03. Z250007 PZ Staff Report

Maricopa County — Planning & Zoning (2025-07-24)

View PDF Item 3 Meeting page

Extracted text (via pymupdf) 153956 characters
Z250007
Page 1 of 9
Report to the Planning and Zoning Commission
Prepared by the Maricopa County Planning and Development Department
Case:
Z250007 – Sierra Luna BESS Facility
Hearing Date:
July 24, 2025
Supervisor District:
5
Applicant:
Christy Eichorn, Plus Power 
Owner:
Marwest Enterprises LLC 
  
Request:
Zone Change with Overlay from Rural-43 to IND-2 IUPD 
 
Site Location:
Generally located 750’ northeast of Avondale Blvd. and Broadway Rd. in the 
Avondale area
 
Site Size:
Approx. 18.47 acres
Density:
N/A
County Island: 
Yes, City of Avondale
County Plan:
Rural Development Area
Municipal Plan:
City of Avondale – Local Commercial
Municipal Comments:
City of Avondale - Supportive
Support/Opposition:
Four letters in support
Recommendation:
Approve with conditions

Z250007
Page 2 of 9
Project Summary:
1.
The IND-2 IUPD zoning will facilitate development of a proposed a Battery Energy Storage System 
(BESS) facility 750’ northeast of Broadway Road and Avondale Boulevard in the Avondale area. 
The site spans several parcels within a county island extending south toward the Salt River, 
bordered by the City of Avondale to the north and west. An SRP canal separates the site from 
direct access to Avondale Boulevard. The facility will interconnect with the nearby Ruud 
Substation, located several hundred feet west in Avondale jurisdiction. Upon completion, the 
facility will include 408 battery cabinets and will store approximately 150MW. This will be the 
second BESS project tied to the substation, following the Sierra Estrella BESS, completed in 2024.
2.
The BESS facility will operate continuously with up to five on-site staff monitoring operations. A 
development agreement between the applicant and the City of Avondale requires the developer 
to coordinate fire and medical training with both Avondale and Rural Metro due to fire safety 
concerns associated with BESS cabinets. The agreement also mandates construction of two 
24,000-gallon water tanks for emergency response, along with a third-party contract to maintain 
water supply.
3.
The IUPD proposes increased setbacks for BESS units from the base IND-2 zoning district’s 
setback requirements.  According to the applicant this reflects advances in BESS safety 
standards. The applicant requests a 100-foot setback from all property lines to battery 
enclosures—for emergency fire-fighting staging and refuge.  Earlier BESS proposals included a 
500-foot separation from existing residential. The applicant argues this amount of separation is 
unnecessary as improved BESS technology poses less fire and smoke risks. This specific BESS 
setback is not codified in the ordinance but has been crafted in consultation with the local fire 
authority. Other IUPD provisions align with recent BESS approvals processed by the County. No 
Plan of Development is proposed with this application.
REGULATION
BASE ZONING DISTRICT 
REGULATIONS (IND-2)
PROPOSED ZONING DISTRICT 
REGULATIONS (IND-2 IUPD)
Minimum Front Yard
20'
20’ (100’ for battery enclosures)
Minimum Side Yard
5’
5’ (100’ for battery enclosures)
Minimum Street-side Yard
10'
10’ (100’ for battery enclosures)
Minimum Rear Yard
25'
25’ (100’ for battery enclosures)
Parking Spaces
See parking regulations
3 spaces plus one ADA stall
Screening
6' solid wall
8’ Masonry Wall
Additional Regulations
Art. 902.9.1.
Battery Energy Storage System 
components may be located 
outside of enclosed buildings
Paving
Art. 1102.7.1.
Gravel surface with compacted 
subgrade of native soil
Allowed Uses
Art. 902.2.
Battery Energy Storage System

Z250007
Page 3 of 9
Aerial photo of subject site, oriented north
Aerial image & surrounding environs showing recent developments

Z250007
Page 4 of 9
Eagle view of subject site looking north into subject parcel (aerial image dated March 2nd, 2025)
Conceptual site plan

Z250007
Page 5 of 9
Portion of conceptual site plan showing distance from cabinets to Rural-43 Zoning District
Existing On-Site and Adjacent Zoning / Land Use:
4.
On-site:
Rural-43 / Vacant
North:
SRP Canal then City of Avondale / Future Residential 
South:
Rural-43 / Residential
East:
Rural-43 / Residential
West:
Avondale Blvd then City of Avondale / Future Commercial
Zoning District map

Z250007
Page 6 of 9
Utilities and Services:
5.
Water:
Well
Wastewater:
Septic
Fire:
City of Avondale/Rural Metro
Police: 
MCSO 
Right-of-Way:
6.
The following table includes existing and proposed half-width right-of-way and the future 
classification based upon the Maricopa County Department of Transportation (MCDOT) Major 
Streets and Routes Plan. Avondale Blvd at the site is under the jurisdiction of the City of Avondale.
Street Name
Half-width Existing R/W
Half-width Proposed R/W
Future Classification
Broadway Rd.
36’
40’
Minor Arterial
Adopted Plan:
7.
Avondale General Plan 2030 (adopted December 4, 2023): Local Commercial: Land use category 
that is used primarily for providing daily needs of goods and services to the residents residing 
within the surrounding area. The types of uses allowed in this category specifically for local 
residents may include: grocery stores, gas stations, neighborhood/retail services, and office and 
medical uses serving consumers residing in adjacent residential areas, which promotes a 
walkable community. Preferred locations are major arterial intersections, although other 
locations may be deemed acceptable based on the merits of the project. In addition, services that 
provide shopping and basic services for the immediate area (i.e. “neighborhood commercial”) 
may be allowed in any land-use classification based upon the merits of the development proposal. 
Generally neighborhood commercial development would not be greater than five acres, and would 
require adequate buffering to protect surrounding land uses.
Public Participation Summary:
8.
The applicant complied with the Maricopa County Public Participation Process with the required 
posting of the property and notification by first class mail to the adjacent property owners within 
300’ of the subject site and interested parties. Staff received four letters of support in addition to 
the approved development agreement between the City of Avondale and the applicant.
9.
The support letters come from members of the Phoenix business community, including the 
Arizona chapter of the Chamber of Commerce, the Arizona Commerce Authority, the Arizona Tech 
Council, and the Western Maricopa Coalition. They all speak to the necessity of the project given 
the rising demand of energy throughout the valley, and that the project would be an important 
component of ensuring such energy would remain available during peak demand hours.
10.
The applicant and the City of Avondale were in frequent communication throughout the review 
period of the project. Although not directly expressed to staff, City of Avondale staff had apparent 
concerns regarding ensuring appropriate access to the site in addition to appropriate fire 
servicing. These discussions ultimately led to a development agreement between Avondale and 
the applicant regarding certain measures that would allow for site development. This 
development agreement was approved by Avondale’s City Council on July 7, 2025. While the

Z250007
Page 7 of 9
County is not party to this agreement, staff has implemented terms of the agreement as part of 
this zone change to be enforceable with a future Plan of Development application for the site.
Outstanding Concerns from Reviewing Agencies:
11.
Although the project does not meet the land-use designation within the Avondale General Plan, 
staff notes the approval of Avondale’s City Council of the development agreement as an approval 
of the proposed land-use. Staff is appreciative of the efforts of the applicant in working with the 
City of Avondale on procuring this agreement. 
Staff Analysis:
12.
Staff supports IND-2 IUPD zoning at this site because the proposed BESS use would help protect 
the Valley’s energy grid during this period of rapid development and represents an appropriate 
land-use for this site considering its proximity to the nearby substation and power lines. BESS 
facilities are becoming increasingly common in the Valley, helping to meet rising energy demands 
by supplying additional load during peak hours and reducing the risk of grid failure.
Recommendation:
13.
Staff recommends the Commission adopt a motion recommending that the Board of Supervisors 
approve Z250007 subject to the following conditions ‘a’ – ‘j’:
a.
Development of the site shall be in substantial conformance with the Site Plan entitled “Sierra 
Luna Energy Storage Project“, consisting of 2 full-size sheets, dated July 15, 2025, except as 
modified by the following conditions and as modified by the Plan of Development. 
b.
Development of the site shall be in substantial conformance with the Narrative Report 
entitled “Sierra Luna Energy Storage Narrative Report”, consisting of 60 pages, dated May 9, 
2025, except as modified by the following conditions.
c.
The following Planning Engineering conditions shall apply:
1.
Without the submittal of a precise plan of development, no development approval is 
inferred by this review, including, but not limited to number of proposed  building  
lots/units,  drainage  design,  access  and   roadway alignments. These items will be 
addressed as development plans progress and are submitted to the County for 
further review and/or entitlement.
2.
A traffic impact study must be submitted with future entitlement (POD or Preliminary 
Plat) application(s). Due to the preliminary nature of this zone change request 
MCDOT traffic did not comment on the zone change review and will make comments 
once more details are provided in the future entitlements.
3.
Engineering review of re-zone cases is conceptual in nature. All development and 
engineering design shall be in conformance with Section 1205 of the Maricopa 
County Zoning Ordinance; Drainage Policies and Standards; Floodplain Regulations 
for Maricopa County; MCDOT Roadway Design Manual; and current engineering 
policies, standards and best practices at the time of application for construction.
d.
The following IND-2 IUPD standards shall apply:
1.
Minimum Front Yard: 20’ (100’ for battery enclosures)

Z250007
Page 8 of 9
2.
Minimum Side Yard: 5’ (100’ for battery enclosures)
3.
Minimum Street-side Yard: 10’ (100’ for battery enclosures)
4.
Minimum Rear Yard: 25’ (100’ for battery enclosures)
5.
Parking Spaces: Min. 3 spaces plus one ADA stall
6.
Screening: Min. 8’ masonry wall
7.
Additional Regulations: Battery Energy Storage System components may be located 
outside of enclosed buildings
8.
Paving: Gravel surface with compacted subgrade of native soil
e.
The IND-2 zoning is subject to an Industrial Unit Planned Development (IUPD) Overlay that 
limits the entitled use to battery energy storage facilities and ancillary uses, or other uses 
determined by both the Planning & Development Department and the Environmental Services 
Department as appropriate and that can accommodate wastewater disposal via on-site 
septic systems or a third-party wastewater management provider. . The IUPD may be deleted 
or amended to entitle additional uses via Modification of Condition application to the 
Planning & Development Department but will require legislative approval by the Board of 
Supervisors after recommendation of the Planning & Zoning Commission.
f.
Administrative approval of a POD will be required prior to approval and issuance of 
construction permits to develop and establish use of the site. Prior to issuance of a building 
permit, written confirmation will be required from the emergency fire protection jurisdiction 
having authority that the facility has been designed in accordance with their regulations and 
requirements, and that emergency fire protection service will be provided to the facility. Prior 
to issuance of the certificate of occupancy, local fire protection jurisdiction review and 
approval will be required.
g.
The following Plan of Development conditions per the City of Avondale development 
agreement shall apply:
1.
Developer shall coordinate with the City of Avondale Fire and Medical Department 
and Rural Metro to provide onsite training at Developer’s expense.
2.
Developer shall provide two (2) access driveways to the Property from South 113th 
Avenue.
3.
Battery unit spacing shall comply with NFPA 855 and OSHA 1926.
4.
Developer shall install two (2) 24,000-gallon water tanks on site, with access 
connections located outside the perimeter wall.
5.
Developer shall retain a third-party service provider to refill water tanks as needed to 
support emergency response.
h.
Noncompliance with any of the conditions assigned to the approval of this Zone Change by 
the Maricopa County Board of Supervisors may be grounds for revocation in accordance with 
the requirements and procedures as set forth in the Maricopa County Zoning Ordinance.
i.
The property owner/s and their successors waive claim for diminution in value if the County 
takes action to rescind approval due to noncompliance with conditions.
j.
The granting of this change in use of the property has been at the request of the applicant, 
with the consent of the landowner. The granting of this approval allows the property to enjoy 
uses in excess of those permitted by the zoning existing on the date of application, subject 
to conditions. In the event of the failure to comply with any condition, the property may be 
considered for revocation to the zoning that existed on the date of application. It is, therefore,

Z250007
Page 9 of 9
stipulated and agreed that either revocation due to the failure to comply with any conditions, 
does not reduce any rights that existed on the date of application to use, divide, sell or 
possess the property and that there would be no diminution in value of the property from the 
value it held on the date of application due to such revocation of the Zone Change. The Zone 
Change enhances the value of the property above its value as of the date the Zone Change 
is granted and reverting to the prior zoning results in the same value of the property as if the 
Zone Change had never been granted.
Presented by:
Joel Landis, Planner
Reviewed by:
Rachel Applegate, Planning Supervisor
Attachments:
Case Map (1 page)
Site Plan (2 pages)
Narrative Report (60 pages)
MC PND Engineering comments (2 pages)
Support Letters (4 pages)
Approved development agreement (17 pages)

/
Maricopa County Planning & Development - Phoenix, AZ
5
Gross Acres: 18 approx.
Generated June 25, 2025 8:26 AM
Z250007
Application Name:
Legal Description
Sierra Luna Energy Storage
Applicant
Case Address
1N 1E 19
Peter Furlow
4025 S AVONDALE BLVD
Applicant Phone/Email
Parcel Primary:101-23-002F
(402) 575-8000
peter.furlow@quarles.com
TOLLESON, AZ 85353
Map scale 1:2,854
Supervisor District No.
Zone Change with Overlay Request from Rural-43 (RU-43) to Light Industrial (IND-2) and Industrial Unit
Plan of Development (IUPD) for proposed battery energy storage facility.

S.1
SIERRA LUNA ENERGY
STORAGE PROJECT
150MW / 1200MWH
COVER SHEET
UTILITY COMMITMENT TABLE
WATER
N/A
WASTEWATER
N/A
FIRE PROTECTION
RURAL METRO FIRE
POLICE PROTECTION
MARICOPA COUNTY SHERIFF'S OFFICE
ELECTRIC
SALT RIVER PROJECT
NATURAL GAS
N/A
TELEPHONE
N/A
REFUSE
TBD
SITE SUMMARY TABLE
GROSS ACREAGE
18.47 ACRES
NET ACREAGE
17.74 ACRES
EXISTING ZONING & LAND USE
ZONE: RURAL-43 (RU-43)
USE: VACANT
PROPOSED ZONING & LAND USE
ZONE: LIGHT INDUSTRIAL (IND-2) WITH IUPD OVERLAY
USE: BATTERY ENERGY STORAGE SYSTEM
REQUEST
ZONE CHANGE FROM RU-43 TO IND-2 WITH IUPD OVERLAY FOR SIERRA
LUNA ENERGY STORAGE.
IUPD COMPARISON CHART
REGULATION
BASE ZONING DISTRICT REGULATIONS
(IND-2)
PROPOSED ZONING DISTRICT REGULATIONS
(IND-2 IUPD)
MAXIMUM BUILDING HEIGHT
40'
40'
MINIMUM FRONT YARD
20' (ABUTTING A SECTION LINE ROAD)
20' (ABUTTING A SECTION LINE ROAD) EXCEPT 100' FROM
BATTERY ENCLOSURES TO PROPERTY LINE*
MINIMUM SIDE YARD
5' (ADJACENT TO RURAL OR RESIDENTIAL ZONING
DISTRICT)
5' (ADJACENT TO RURAL OR RESIDENTIAL ZONING
DISTRICT) EXCEPT 100' FROM BATTERY ENCLOSURES TO
PROPERTY LINE*
MINIMUM STREET-SIDE YARD
10' (STREET SIDE OF CORNER LOT ABUTTING RURAL
RESIDENTIAL ZONING DISTRICT)
10' (STREET SIDE OF CORNER LOT ABUTTING RURAL
RESIDENTIAL ZONING DISTRICT) EXCEPT 100' FROM
BATTERY ENCLOSURES TO PROPERTY LINE*
MINIMUM REAR YARD
25' (ABUTTING A RURAL OR RESIDENTIAL ZONING
DISTRICT)
25' (ABUTTING A RURAL OR RESIDENTIAL ZONING DISTRICT)
EXCEPT 100' FROM BATTERY ENCLOSURES TO PROPERTY
LINE*
MINIMUM LOT AREA
6,000 SQ. FT.
6,000 SQ. FT.
MINIMUM LOT WIDTH *
60'
60'
MAXIMUM LOT COVERAGE
60%
60%
PARKING SPACES
OFFICE: 1 SPACE PER 250 SF
INDUSTRIAL: 1 SPACE PER 600 SF
OFFICE: 1 SPACE PER 250 SF
INDUSTRIAL: 3 SPACES PLUS 1 ADA STALL
PERIMETER SCREENING
6' MASONRY WALL
8' MASONRY WALL
ADDITIONAL REGULATIONS
ARTICLE 902.9.1. ALL USES EXCEPT FOR PARKING,
LOADING, UNLOADING OR STORAGE SHALL BE
CONDUCTED WITHIN A COMPLETELY ENCLOSED
BUILDING
BATTERY ENERGY STORAGE SYSTEMS COMPONENTS MAY
BE LOCATED OUTSIDE OF ENCLOSED BUILDINGS.
PAVING
ARTICLE 1102.7.1. FOR OTHER THAN ONE SINGLE-FAMILY
DWELLING UNIT OR ONE MOBILE HOME ON A LOT OF
RECORD, ANY PARKING AREA MUST BE PAVED OR IN THE
ALTERNATIVE SURFACED WITH AGGREGATE BASE
COURSE MATERIAL.
GRAVEL SURFACE WITH COMPACTED SUBGRADE OF
NATIVE SOIL.
SIERRA LUNA ENERGY STORAGE PROJECT
ZONE CHANGE WITH OVERLAY REQUEST FROM RURAL-43 (RU-43) TO LIGHT INDUSTRIAL
(IND-2) AND INDUSTRIAL UNIT PLAN OF DEVELOPMENT (IUPD)
CASE #Z250007
*THE APPLICANT ALSO REQUESTS THAT THESE SETBACK AREAS ALLOW FOR DRAINAGE CHANNELS, PERIMETER WALLS, ACCESSWAYS, SIGNAGE,
OR OTHER IMPROVEMENTS PER THE SETBACKS OF THE UNDERLYING IND-2 ZONING DISTRICT BUT EXCLUDING BATTERY STORAGE UNITS.
VICINITY MAP
(NOT-TO-SCALE)
N
GENERAL NOTES
1.
PROJECT IS LOCATED IN SCHOOL DISTRICT LITTLETON #65 IN TOLLESON UNION HS #214.
BATTERY ENERGY STORAGE IS THE ONLY PERMITTED USE IN THE IUPD OVERLAY

APN: 101-23-012C
APN: 101-23-012D
ɸ1
ɸ2
ɸ3
ɸ3
ɸ2
ɸ1
E
E
E
CAPBANK
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
E
E
E
FLOOD CHANNELIZATION AND
STORMWATER RETENTION AREA
RETENTION POND
APN: 101-23-002E
JENNINGS JAMES D/NANCY M TR
ZONE: RU-43
APN: 101-23-002G
MARTINEZ JAIME L/MARIA L
ZONE: RU-43
APN: 101-23-006A
MARWEST ENTERPRISES LLC
ZONE: RU-43
APN: 101-23-013A
MARWEST ENTERPRISES
ZONE: RU-43
APN: 101-23-012E
S. 113TH AVE.
APN: 101-23-002F
SRP CANAL
SRP CANAL
40'
10'
25'
10'
20'
8'
60'
12'
20'
8'
APN: 101-23-002G
JAIME AND MARIA MARTINEZ
ZONE: RU-43
R45' (TYP.)
8'-6"
(TYP.)
20'
20' (TYP.)
20' (TYP.)
20'
230 KV TRANSMISSION LINE
TO RUDD SUBSTATION
SITE ENTRANCE (TYP.)
SITE ENTRANCE
EXISTING PROPERTY LINE
50' R/W FOR S. 113TH AVE EXPANSION
TO BE CONSTRUCTED BY OTHERS
PERIMETER WALL
(APPROX. HT. = 8'+)
100' SETBACK FROM PROPERTY LINES
CONTROL ENCLOSURE
(APPROX. HT. = 14')
PARKING AREA
LIGHT POLE (TYP.)
(APPROX. HT. = 20'. SEE NOTE 4)
MOBILE OFFICE TRAILER
(APPROX. HT. = 14')
PARKING AREA INCLUDING 1 ADA STALL
PROJECT SUBSTATION FENCE
SAFETY & SECURITY
 SIGNAGE (TYP. SEE NOTE 5)
HIGH VOLTAGE
CIRCUIT BREAKER
MAIN POWER
TRANSFORMER
MEDIUM VOLTAGE FEEDER BAYS
112'
156'
137'
141'
20'
S. AVONDALE BLVD.
171'
223'
50'
174'
SPARE EQUIPMENT
STORAGE
90°
409'
TEMPORARY DRAINAGE EASEMENT
TO BE INCORPORATED INTO DESIGN
FUTURE AUGMENTATION AREA
(SEE NOTE 7)
90'
189'
122'
113'
47'
63'
47'
63'
11'
36'
230 KV TRANSMISSION POLE
(APPROX. HT. = 120')
S
S
G
S
APN: 101-23-002H
MARTINEZ JAIME L/MARIA L
ZONE: RU-43
APN: 101-23-007B
CLIFFORD MOORHEAD LIVING TRUST
ZONE: RU-43
STORAGE CONTAINERS
W/ SHADE
STRUCTURE (TYP.)
(APPROX. HT. = 30')
DEADEND
STRUCTURE
(APPROX. HT. = 80')
24'
24,000 GALLON WATER TANK
(APPROX. HT. = 10')
5'
90°
24'
24,000 GALLON WATER TANK
(APPROX. HT. = 10')
12'
8'
111'
BATTERY  AND
INVERTER
CONTAINER (TYP.)
MEDIUM VOLTAGE
TRANSFORMER
FUTURE
AUGMENTATION
N
S.2
SIERRA LUNA ENERGY
STORAGE PROJECT
150MW / 1200MWH
NOTES
1.
THIS IS A PRELIMINARY DESIGN NOT FOR
CONSTRUCTION.
2.
ALL SPECIFIED DIMENSIONS  AND EQUIPMENT
QUANTITIES ARE FOR REFERENCE ONLY. FINAL
EQUIPMENT SPECIFICATIONS TO BE DETERMINED AT
CONSTRUCTION.
3.
SITE ACCESS FOR FIRE VEHICLES  TO FOLLOW
REQUIREMENTS WITHIN NFPA 1 SECTION 18.2.3.
4.
LIGHT FIXTURES TO COMPLY WITH SECTION 1112 OF
THE MARICOPA COUNTY ZONING ORDINANCE.
5.
SIGNAGE WILL BE INSTALLED IN ACCORDACE WITH
MARICOPA COUNTY ZONING ORDINANCE. FURTHER
DESIGN DETAILS TO BE PROVIDED DURING PLAN OF
DEVELOPMENT SUBMITTAL.
6.
LAYOUT INCLUDES 336 BATTERY ENCLOSURES WITH
84 MEDIUM VOLTAGE TRANSFORMERS EXPECTED TO
BE INSTALLED AT BEGINNING OF PROJECT LIFE.
7.
QUANTITY AND SPECIFICATIONS OF BATTERY
ENCLOSURES AND APPURTENANCES USED IN
FUTURE AUGMENTATION AREA WILL BE DETERMINED
AT THE TIME OF CONSTRUCTION OVER THE LIFE OF
THE FACILITY.
8.
TOTAL PARCEL AREA IS APPROXIMATELY 18.5 AC.
9.
TOTAL DEVELOPED AREA IS APPROXIMATELY 9.7 AC.
10.
THIS SITE PLAN IS CONCEPTUAL IN NATURE AND IS
SUBJECT TO MODIFICATION PER THE MARICOPA
COUNTY ADMINISTRATIVE PLAN OF DEVELOPMENT
APPROVAL PROCESS.
PROJECT SITE PLAN
LEGEND
SETBACKS
CHAIN LINK FENCE
PERIMETER WALL
SAFETY & SECURITY SIGNAGE
LIGHT POLE
PROJECT PROPERTY LINES
GRAVEL SURFACING
FUTURE AUGMENTATION
ACCESS GATE
PROPOSED OVERHEAD ELECTRIC
OTHER PROPERTY LINES
EXISTING EASEMENTS
BATTERY SYSTEM LAYOUT

SIERRA LUNA ENERGY STORAGE 
NARRATIVE REPORT 
 
 
 
 
 
 
 
 
 
Zone Change with Overlay Request from Rural-43 (RU-43) to 
Light Industrial (IND-2) and Industrial Unit Plan of Development (IUPD)  
Northeast of the intersection of S. Avondale Boulevard and W. Broadway Road 
 
Case No. Z250007 
Applicant: Sierra Luna Energy Storage LLC  
 
Applicant’s Agent: 
 
Ben Graff, Esq. 
Peter Furlow, Esq. 
Quarles & Brady LLP 
2 N. Central Ave. 
Phoenix, AZ 85004 
 
First Submittal Date: February 28th, 2025  
Second Submittal Date: May 9th, 2025

Sierra Luna Energy Storage 
Narrative Report  
Page 2 
May 9, 2025 
 
 
 
Table of Contents 
1. 
PURPOSE OF REQUEST ............................................................................................................... 2 
2. 
DESCRIPTION OF PROPOSAL ...................................................................................................... 5 
2.1 
APPLICATION SUMMARY AND CONTACTS ............................................................................................ 5 
2.2 
PROPOSED USE .......................................................................................................................... 6 
2.3 
PROJECT NEED ............................................................................................................................ 6 
2.4 
PROJECT PARTNERSHIPS ................................................................................................................ 8 
2.5 
OPERATIONS .............................................................................................................................. 8 
2.6 
SITE CONSIDERATIONS .................................................................................................................. 8 
2.6.1 
Setbacks ............................................................................................................................. 9 
2.6.2 
Parking ................................................................................................................................ 9 
2.6.3 
Signage ............................................................................................................................... 9 
2.6.4 
Screening and Landscaping ................................................................................................. 9 
2.6.5 
Perimeter Fencing and Security ............................................................................................ 9 
2.6.6 
Perimeter Landscaping ........................................................................................................ 9 
2.6.7 
Lighting ............................................................................................................................. 10 
2.6.8 
On-site surfacing and preliminary Civil Design ..................................................................... 10 
2.6.9 
Floodplain ......................................................................................................................... 10 
2.7 
SAFETY CODES AND STANDARDS ................................................................................................... 10 
3. 
RELATIONSHIP TO SURROUNDING PROPERTIES ........................................................................ 11 
3.1 
BENEFITS OF GRID-SCALE ENERGY STORAGE .................................................................................... 11 
3.2 
COMMUNITY BENEFITS ................................................................................................................ 12 
4. 
LOCATION AND ACCESSIBILITY ................................................................................................. 15 
5. 
CIRCULATION SYSTEM .............................................................................................................. 17 
6. 
ANTICIPATED DEVELOPMENT SCHEDULE .................................................................................. 17 
7. 
COMMUNITY FACILITIES AND SERVICES ................................................................................... 17 
8. 
PUBLIC UTILITIES AND SERVICES .............................................................................................. 17 
8.1 
WATER AND SEWER .................................................................................................................... 18 
8.2 
FIRE PROTECTION MEASURES ....................................................................................................... 18 
9. 
IUPD COMPARISON CHART ...................................................................................................... 20 
10. 
COMPREHENSIVE PLAN COMPLIANCE .................................................................................. 21 
10.1 
COUNTY COMPREHENSIVE PLAN COMPLIANCE ................................................................................. 21 
10.2 
CITY OF AVONDALE 2030 GENERAL PLAN ........................................................................................ 22 
10.3 
COORDINATION WITH CITY OF AVONDALE ........................................................................................ 22 
10.4 
OUTREACH AND COMMUNITY PARTICIPATION PLAN ............................................................................ 23 
11. 
OTHER PROJECT-SPECIFIC INFORMATION ............................................................................. 23 
11.1 
BATTERY ENERGY STORAGE SYSTEM DETAIL ...................................................................................... 23

Sierra Luna Energy Storage 
Narrative Report  
Page 3 
May 9, 2025 
 
 
11.2 
PROJECT SUBSTATION ................................................................................................................. 24 
11.3 
TRANSMISSION LINE ................................................................................................................... 25 
11.4 
EXPERIENCE AND NEARBY PROJECTS............................................................................................... 25 
12. 
CONCLUSION ...................................................................................................................... 25 
 
 
APPENDICES 
Appendix A – Zoning Exhibit 
Appendix B – Change of Zone Legal Description  
Appendix C – SRP Ten Year Transmission Plan

Sierra Luna Energy Storage 
Narrative Report  
Page 4 
May 9, 2025 
 
 
 
1. 
Purpose of Request 
Sierra Luna Energy Storage LLC ("Applicant"), an indirect subsidiary of Plus Power, is 
seeking a proposed zone change with overlay from Rural-43 (“RU-43”) to Light Industrial 
(“IND-2”) with an Industrial Unit Plan of Development (“IUPD”) Overlay for the approximate 
18.5 acres property located at Maricopa County Assessor’s Parcel Nos. 101-23-012E, 101-
23-002F, 101-23-012D, and 101-23-012C (the “Property”). The proposed project is a 
standalone battery energy storage system (“BESS”) with a capacity of 150 megawatt (“MW”) 
/ 1,200 megawatt-hour (“MWh”) and an on-site substation connecting to the existing 230 
kilovolt (“kV”) Rudd Substation co-owned by Salt River Project (“SRP”) and Arizona Public 
Service (“APS”). The project is referred to as “Sierra Luna” or the “Project.” Located 
northeast of south Avondale Boulevard and west Broadway Road, the Project is optimally 
located approximately 2,640 feet from the existing Rudd Substation.  
The Property is currently zoned RU-43 and does not fall within any overlay districts. Although 
BESS uses are not explicitly referenced in the Maricopa County Zoning Ordinance (“MCZO”), 
the Maricopa County Planning and Development Department has issued a formal 
interpretation which states BESS uses are permitted as-of-right under the IND-2 zoning 
district. 
The proposed IUPD overlay includes deviations from the underlying IND-2 district 
development standards to accommodate special design requirements for the proposed 
Project and to provide flexibility to the overall design. The proposed IUPD overlay for Project 
will limit uses to BESS facilities and ancillary uses. It will also establish setbacks for battery 
storage units of at least 100-feet from all adjoining property lines. Other requirements, such 
as parking and height requirements are provided in the IUPD Comparison Chart in Section 9 
of this narrative. An administrative Plan of Development (“POD”) application will be 
submitted in the future consistent with the development standards outlined in this zone 
change with overlay request. Approved administratively following the County’s approval of 
the zone change, the POD will provide a more detailed site plan and give further details on 
the proposed use on the Property. 
With fire safety, and the safety of our local first responders as the most important item of 
consideration in this application, we have provided robust information on our fire safety plan 
in Section 8.2 of this narrative.  Additionally, we are proactively requesting that County Staff 
include and require a stipulation as part of the rezone approval which provides express 
powers to Rural Metro to review and approve all plans prior to the issuance of building 
permits and any certificates of occupancy.  The proposed stipulation language can be found 
in Section 8.2 of this narrative.

Sierra Luna Energy Storage 
Narrative Report  
Page 5 
May 9, 2025 
 
 
2. 
Description of Proposal 
2.1 
Application Summary and Contacts 
Applicant: Sierra Luna Energy Storage, LLC 
Current Landowner: Marwest Enterprises LLC / Camarus LLC 
Project Representatives:  
Christy Eichorn, AICP, Senior Permitting Manager ceichorn@pluspower.com 
Stuart Coles, Senior Development Manager scoles@pluspower.com 
Authorized Agents:  
Quarles & Brady LLP: Benjamin Graff, Benjamin.graff@quarles.com 
Coe Van Loo Consultants Inc: Parker Froehlich, pfroehlich@cvlci.com  
Location of Project: Four unaddressed parcels located northeast of the intersection of 
S. Avondale Blvd. and W. Broadway Road.  
Parcel Number 
Number of Acres 
10123012C 
1.0 
10123012D 
0.87 
10123012E 
15.6 
10123002F 
1.0 
Total 
18.47 
Proposed Zone Change and Overlay Area: 18.47 acres 
Special Land Designations: Federal Emergency Management Agency, Special Flood 
Hazard Area (Zone AE) with a 1% annual flood risk.  
Existing Use: Vacant 
Utility Providers: 
WATER 
ON SITE WATER TANKS  
WASTEWATER 
N/A 
FIRE PROTECTION 
RURAL METRO FIRE 
POLICE PROTECTION 
MARICOPA COUNTY SHERIFF’S OFFICE 
ELECTRIC 
SALT RIVER PROJECT 
NATURAL GAS 
N/A 
TELEPHONE 
N/A 
REFUSE 
TBD

Sierra Luna Energy Storage 
Narrative Report  
Page 6 
May 9, 2025 
 
 
2.2 
Proposed Use 
The Project is a grid-scale, standalone BESS that will provide 150MW of on demand 
power to the grid to service tens of thousands of homes for up to eight hours. The 
Project’s batteries will charge directly from the local grid, via the electricity provided by 
an interconnection to the existing 230-kV Rudd Substation, and discharge electricity 
through the same path back into the existing substation. With this vacant site 
approximately 2,640 feet from the Rudd Substation, it offers a unique opportunity to 
meet the West Valley’s electrical grid stability needs with a minimum amount of 
powerline infrastructure. The Project consists of the following components: 
• Grid-scale BESS containers (approximately 408 units expected at end-of-life of 
the Project based on preliminary site design)  
• Electrical collection systems, including transformers 
• High-voltage transmission line and associated facilities 
• Project substation consisting of typical electrical equipment and a control 
enclosure 
• Maintenance area consisting of unoccupied storage containers and shade 
structures for operation and maintenance 
• Mobile office trailer 
• Solid perimeter wall (minimum height of 8 feet) for screening and security 
• Landscaping and vegetative screening  
• Above-ground water tank 
• Access elements including gates, interior access roads, and on-site parking 
• Civil design features including drainage channels and retentions basins.  
 
Construction is expected to begin in 2028, with service starting in 2029. The zone change 
will allow the construction and operation of the BESS and appurtenances on the 
Property. 
2.3 
Project Need 
There is an quantifiable need for BESS projects over the next decade in the West Valley. 
In SRP’s 2023 Integrated System Plan, SRP announced plans for over 1,500 MW of new 
energy storage by 2035. Similarly, APS has determined 3,000 MW of energy storage will 
be necessary to address its growing electrical demand load, particularly in the summer, 
and support integration of new renewable energy projects into a reliable and functioning 
grid.

Sierra Luna Energy Storage 
Narrative Report  
Page 7 
May 9, 2025 
 
 
The Rudd Substation, originally constructed in 2022, is an important component of the 
SRP and APS electric grid for the Region. It is important to emphasize that the 
construction of the Rudd Substation brought with it the expectation that surrounding 
land uses would include energy sources such as BESS developments in the near future. 
See SRP Ten Year Transmission Plan attached as Appendix C.   
The Rudd Substation integrates transmission lines at multiple voltage classes and has 
ample hosting capacity for new resources, which makes it a critical location for an energy 
storage project. This specific point of delivery minimizes costs for upgrading the facility 
to allow for the addition of an energy storage system. As a result, the Project will benefit 
the utility, and ratepayers will receive improved grid reliability and integration of 
generation resources.  
Both SRP and APS are continuing to make investments in the Rudd Substation and have 
identified the following upgrades in their transmission planning documents:  
• SRP: Reconductoring the Rudd - Orme 230 kV double circuit line (Operational  2027) 
• APS: Construction of the JoJoba 500 kV - Rudd 500 kV transmission line 
o (Commercial Operation Date 2028)  
• APS: Construction of the White Tanks - Rudd 230 kV transmission line 
o (Commercial Operation Date 2024) 
In 2024, Plus Power completed the Sierra Estrella Energy Storage Project in Avondale, AZ 
which also connects directly to the Rudd Substation.  
The Sierra Estrella Energy Storage Project came online in the summer of 2024 during peak 
demand for regional utilities and Phoenix. At the time, Jim Pratt, SRP’s chief executive 
officer stated: 
“We appreciate our partnership with Plus Power to develop these resources, 
which will provide flexibility and resource diversity to help maintain reliable 
power during Arizona’s hot summers…We are proud to be leading the way with 
integrating new energy technology to serve our customers.” 
SRP estimated that energy storage projects like these supplied more than 10% of its 
peak-hours electricity demand in 2024, the equivalent of the electricity used by 
approximately 180,000 homes. Both the continued investment in the Rudd Substation 
and the commitment from SRP to incorporate energy storage into its system emphasize 
the opportunity for the Project to support Maricopa County’s existing electric grid where 
it is needed most.

Sierra Luna Energy Storage 
Narrative Report  
Page 8 
May 9, 2025 
 
 
2.4 
Project Partnerships  
Sierra Luna Energy Storage LLC is a leader in standalone battery energy storage projects 
in the United States. Plus Power operates seven systems nationwide, with two additional 
systems anticipated to commence operations in 2025. Two of the seven operational 
projects are in Arizona, with one in Gilbert and one in Avondale. Plus Power partners with 
local governments, utilities, and stakeholders in those communities and will continue to 
foster productive relationships. Plus Power seeks to establish a similar partnership with 
Maricopa County and adjacent jurisdictions, including Avondale, to ensure transparent 
communication and thoughtful development for this critical energy infrastructure 
project to support the West Valley. 
2.5 
Operations 
The BESS will be operational 24 hours a day seven days a week. After construction is 
complete, up to five technicians are anticipated to be on site during normal business 
hours maintaining and monitoring equipment. In addition to the BESS, there will be a 
trailer on site to accommodate operations and maintenance staff.  There will be a control 
enclosure  located in the Project substation to house equipment for monitoring and 
controls. Equipment staging areas will consist of storage containers and shade 
structures covering approximately ten thousand square feet in area.  
2.6 
Site Considerations 
The Project is designed to minimize impacts on local land uses and resources, manage 
floodplain distribution responsibly, and blend with the surrounding area's aesthetics. 
To maintain the Project’s energy storage capacity and efficiency throughout its lifetime, 
augmentation of the Project’s battery enclosures will be necessary. Augmentation is the 
process of adding more BESS capacity to compensate for the natural degradation of the 
capacity of the BESS installed initially. Augmentation is anticipated to include repair, 
replacement and installation of new battery enclosures. The exact specifications and 
dimensions of the battery enclosures and associated equipment used for augmentation 
will vary and will be determined at the time of installation, utilizing state-of-the-art 
technology at that time. The site plan included in this application includes both the initial 
phase of build-out and anticipated future augmentation.

Sierra Luna Energy Storage 
Narrative Report  
Page 9 
May 9, 2025 
 
 
2.6.1 Setbacks 
The site will have 100-foot setbacks between all battery enclosures and Property lot 
lines in compliance with the 2023 version of National Fire Protection Association 
(“NFPA”) 855 which applies to remote facilities such as this Project. 
2.6.2 Parking 
The proposed development will have five parking stalls in compliance with the MCZO. 
Separate from employee parking, an approximate one thousand square foot area will 
also be solely dedicated to first responders and allow for a fire staging area. 
2.6.3 Signage  
During all phases of this Project, signage for safety and identification will be posted 
around the perimeter of the project site The Project will comply with minimum 
standard safety signage around its perimeter. Any and all signage will conform to 
MCZO Chapter 14 Section 14.04 requirements. 
2.6.4 Screening and Landscaping  
The proposed BESS will have no negative impact on neighbouring parcels and is 
compatible with the nearby existing high-voltage transmission lines, stables, planned 
data center, and substation. The Applicant has committed to installing a minimum 8-
foot-tall wall on all sides to visually screen the batteries and secure the site. The wall 
will resemble similar walls found along Avondale Boulevard for commercial and 
residential developments typical of the area. Additionally, the 100-foot setback from 
the property boundaries will support screening from major roads, and landscaping 
outside the wall will consist of native vegetation in compliance to landscape 
standards in the MCZO.  
2.6.5 Perimeter Fencing and Security 
The Project will be surrounded by a perimeter wall for aesthetic and security 
purposes. The perimeter wall will be a minimum of eight-feet tall, solid masonry wall 
with two access points. Remote security cameras will be installed to monitor the 
facility 24 hours a day.  
2.6.6 Perimeter Landscaping 
The landscaping will use native species that need no irrigation and will be planted 
around the perimeter of the Project subject to the drainage plan. Extra attention will 
be given to enhancing the landscaping along S. Avondale Boulevard. The 
landscaping will consist of carefully selected native plants that are well-suited to

Sierra Luna Energy Storage 
Narrative Report  
Page 10 
May 9, 2025 
 
 
the local climate and soil conditions, reducing the need for additional water 
resources once they are established. Water trucks will support the plants in early 
growth to ensure establishment. 
2.6.7 Lighting 
Lighting will be installed throughout the site to increase safety and security at night. 
Light fixtures will only be turned on when needed, and they will be designed to direct 
light downwards into the Project site to minimize light pollution. All outdoor lighting 
will be in accordance with Chapter 11, Section 1112 of the Maricopa County Zoning 
Ordinance and all county standards, regulations and requirements.  
2.6.8 On-site surfacing and preliminary Civil Design  
The Applicant has long-standing experience designing all aspects of BESS projects, 
including civil design. The containers will be installed on foundations, while the area 
between containers will likely consist of crushed rock or compacted earth. The 
Project will also include necessary stormwater management improvements, such as 
drainage ditches and detention basins. Design of those features as well as a drainage 
plan will be provided and addressed during the Plan of Development submittal. 
2.6.9 Floodplain 
The Project site is located in the 100-year floodplain. To meet standards and best 
management practices for facility siting, the Project footprint is anticipated to be two 
feet above the existing base flood elevation. As part of future Floodplain permitting 
requirements with Maricopa County, a civil solution will be designed to address 
compliance with the floodplain requirements and minimize changes to surrounding 
hydrological conditions.  
2.7 
Safety Codes and Standards 
The Project will comply with the MCZO, state standards, federal standards, and industry 
safety standards as safety is the Applicant’s top priority. All equipment adheres to national 
and global design and manufacturing standards, ensuring rigorous testing and 
certification prior to equipment placement. Redundant safety systems, including 
temperature regulation, cameras, and proper equipment spacing, are in place to enhance 
system protections. Trained personnel will conduct 24/7 monitoring to maintain continual 
oversight. The NFPA 855 2023 and 2018 International Fire Code (“IFC”) 1207 have 
established standards specifically for standalone battery energy storage and this Project 
will meet those standards, including the setback of 100-feet between property

Sierra Luna Energy Storage 
Narrative Report  
Page 11 
May 9, 2025 
 
 
boundaries and battery energy system enclosures. The battery storage area will also be 
surrounded by a minimum eight-foot-tall perimeter wall with landscaping facing Avondale 
Boulevard.  
An Emergency Response Plan will be prepared in collaboration with local first responders 
prior to the start of operations and will require the Applicant to provide ongoing annual 
training to local responders to maintain preparedness. Compliance with federal, state, 
and local fire and safety codes will be required. In addition, the electric grid reliability that 
results from the use of battery energy storage, in turn, creates more reliability for local 
emergency services, hospitals, industries, and residences, essentially all the customers 
that use electricity from the local electric grid.  
To further ensure fire safety measures are secured for the Project, the Applicant is 
proactively requesting that County Staff include and require a stipulation as part of the 
rezone approval which provides express powers to Rural Metro to review and approve all 
plans prior to the issuance of building permits and any certificates of occupancy. See draft 
stipulation in Section 8.2 of this Narrative. 
 
3. 
Relationship to Surrounding Properties  
3.1 
Benefits of Grid-Scale Energy Storage 
To handle anticipated load growth from increased population, industries such as data 
centers and new renewable power generation resources connecting to the grid, SRP needs 
fast, flexible capacity to provide reliable electricity. Sierra Luna will provide 150 MW of 
storage by charging the batteries when energy is plentiful on the grid, and discharging that 
energy when it’s needed, capable of powering tens of thousands of homes for eight hours 
on demand.  
The Project will provide crucial services and strengthen the grid by: 
• Increasing the stability and resiliency of the electric grid. 
• Supporting affordable rates for local homes and businesses. 
• Adding capacity during times of peak demand in hot, Arizona summers. 
• Delivering electricity in the blink of an eye when the grid needs additional energy. 
• Helping to address intermittent power generation sources like solar and wind.

Sierra Luna Energy Storage 
Narrative Report  
Page 12 
May 9, 2025 
 
 
Storing local energy cuts costs for utilities and consumers, optimizes grid operations, 
reduces upgrades that would otherwise be needed on the existing electric grid, and boosts 
efficiency of the local grid. 
3.2 
Community Benefits  
In addition to utility-scale grid resiliency, the Project will benefit the community by: 
• Generating millions in local tax revenue. 
• Increasing local energy reliability. 
• Helping to reduce consumer costs. 
• Creating well-paying local jobs. 
• Enabling integration of clean energy resources. 
• Providing upgrades to SRP’s transmission network. 
• Attracting new commercial and residential development. 
Standalone energy storage projects provide direct benefits at the local level during the 
permitting, engineering, construction and operation phases of the project. Local 
engineering and consulting firms are already supporting the design of the project during 
the early development phase. Up to 100 on-site construction workers will be needed 
throughout the construction phase of the project, which will occur over an approximate 
12-18 month period. The Sierra Luna construction team will work to guarantee prevailing 
wages. Additionally, construction will benefit secondary industries and local businesses, 
such as hotels, restaurants, and local suppliers, including the associated increase in 
sales tax attributable to such spending.  
Once operational, the Project will bring additional benefits including long-term 
employment for full-time operational and maintenance specialists who will live and work 
in the Avondale area. The proposed BESS will provide crucial reliability of electric power 
necessary for existing and future industrial and residential users in the City of Avondale 
and West Valley area, while also providing a measurable boost in local and state taxes 
from the capital investment. Improved grid reliability can also help support economic 
development in the region as prospective commercial and industrial partners consider 
reliable power in siting decisions for potential investment in the West Valley.   
The Applicant takes siting and safety very seriously. The Project’s location was selected 
because it is compatible with existing and proposed land uses, but also because it is an 
appropriate place to operate an energy project. The Project is near public roads,

Sierra Luna Energy Storage 
Narrative Report  
Page 13 
May 9, 2025 
 
 
facilitating easy site access, as well as a network of high-voltage transmission lines. Figure 
1 and the narrative below depicts and describe surrounding land uses.  
 
Figure 1. Surrounding Land Uses 
West of Property: 
• Buckeye Canal (SRP) – This canal is adjacent to the west separating the Property 
from Avondale Boulevard. The Project incorporates a suitable buffer from all property 
lines, including the SRP property hosting Buckeye Canal, which provides a natural 
setback for travellers driving down Avondale Boulevard. The project fits with this type 
of utility use.  
 
• Planned Area Development (PAD) – On the west side of Avondale Boulevard, in the 
corporate city limits of Avondale is a future planned development that includes 
medium density residential with commercial along Avondale Boulevard. This 
property is currently being used for agriculture. Residential and commercial 
development have not started construction. The Project’s proposed solid perimeter 
wall will resemble nearby residential and commercial developments and will be 
screened from view, which will support consistency and compatibility with future 
residential and commercial development across the street.

Sierra Luna Energy Storage 
Narrative Report  
Page 14 
May 9, 2025 
 
 
• Hermosa Ranch PAD – The City of Avondale approved the Hermosa Ranch PAD to 
facilitate data center and battery energy storage system development. This PAD will 
also host the future interconnection path of the Sierra Luna Project. This PAD is 
across Avondale Boulevard from the proposed stie and demonstrates the Project’s 
consistency and compatibility with nearby development in the City of Avondale. This 
PAD includes the future Prime Data Center (currently undergoing construction 
mobilization) as well as the operating Sierra Estrella battery energy storage facility 
owned by Plus Power. Sierra Estrella became operational in 2024. 
 
• Rudd Substation – The SRP and APS Substation is located adjacent to the Hermosa 
PAD (including the Sierra Estrella Project) and is the point of delivery for the project. 
Vacant land near critical substations, such as Rudd Substation, are vital 
opportunities for local governments to support grid stability and attract capital 
investment. The Property is near the Rudd Substation, which also supports the 
existing transmission network already a main feature of the vicinity.  
North of Property: 
• St. John’s Canal (SRP) – The St. John’s irrigation ditch, also managed by SRP, 
connects directly to the Buckeye canal on the west side of the property and runs 
diagonal from east to west along the north side of the Property. With future 
development in the Project area, a separate SRP parcel will also be created on the 
north side to memorialize SRP’s existing property right. Setbacks incorporate this 
future parcel. Similar to Buckeye Canal, the St. John’s canal does not present an 
obstacle to construction or operations of the facility. The SRP system provides 
additional space between the Project’s solid perimeter wall and any nearby users or 
development. 
 
• City of Goodyear Water Pump Facility – The City of Goodyear operates a water pump 
facility on the north side of the St. John’s canal. This facility supports water 
management for Goodyear and was installed in the last decade. The Project will not 
interfere with the existing facility’s operations. This facility provides an example of 
utility services being located alongside commercial and residential development. No 
project components (such as transmission line poles or other ancillary features) are 
planned for the City of Goodyear property.  
 
• Entrada Development (Meritage Homes): Directly north of the Project is the 
planned Entrada Community being developed by Meritage Homes. Applicant has met

Sierra Luna Energy Storage 
Narrative Report  
Page 15 
May 9, 2025 
 
 
with representatives from Meritage Homes and there is no known objection to the 
project. The Entrada development will use the southern portion of the property 
adjacent to the St. John’s Canal for a detention basin. This provides a natural buffer 
to any new development north of the project. The Project also incorporates Entrada’s 
stormwater management plan and changes to floodplains into its design.  
East of Property: 
• Livestock operations and low density residential: Properties to the east operate 
livestock and stable operations as well as low-density residential. Energy storage 
projects are compatible with both types of land use. The property owner is supportive 
of the project.  
South of Property: 
• Low density residential – Much of the area to the south of the Project is vacant land 
owned by Marwest, the existing landowner for the Sierra Luna Project. To the 
Applicant’s knowledge, there are no near-term plans for this site. There is only one 
other landowner along the property’s southern border. The landowner has a working 
shed on the north side of its property and the main residence is closer to Broadway 
Road. As stated elsewhere, the project will incorporate sizable setbacks to all 
property boundaries. No objection has been raised from the landowner to the south.  
 
4. 
Location and Accessibility 
Location: The Project location was chosen for its proximity to the existing Rudd Substation 
and high voltage transmission lines, the availability of transmission interconnection 
capacity, existing road access, and the previously disturbed nature of the site. 
Additionally, the planned data center and commercial development in the vicinity of the 
site further supports the feasibility of this location for the proposed use. 
Existing Project Site: The Project site is currently a vacant but was historically used as a 
small dairy operation. The Property is zoned RU-43, permitting residential development 
with minimum lot sizes of one acre, as well as agricultural, recreational, and institutional 
uses. 
Accessibility: The Project site will be accessed via S. 113th Ave., which  is being improved 
by Meritage Homes (residential developer to the north) to accommodate a second access 
for future residential properties northeast of the Property. The extension and improvement

Sierra Luna Energy Storage 
Narrative Report  
Page 16 
May 9, 2025 
 
 
of S. 113th Ave. will support construction, operation, maintenance, and emergency 
response access for the Project. Routine operations, maintenance, and inspections will 
occur throughout the Project’s lifecycle, following supplier-directed schedules, 
preventative inspections, and a comprehensive maintenance program.   
 
Figure 2: Entrada Residential Development’s S. 113th Avenue Improvement 
Operations Monitoring: The BESS will be continuously monitored remotely and routinely 
managed on-site by approximately three to five technicians, depending on operational 
requirements. A self-contained office trailer will be positioned on the Property. 
Technicians are expected to be present each weekday during normal business hours, with 
occasional night-time or weekend work as necessitated by the system's needs. The 
facility will operate continuously and the traffic resulting from the workers is anticipated 
to be minimal.  
 
ENTRADA DEVELOPMENT

Sierra Luna Energy Storage 
Narrative Report  
Page 17 
May 9, 2025 
 
 
5. 
Circulation System  
The rezoned parcels will be accessible from an improved S. 113th Street at two locations: 
one at the north end of the facility and one at the south. Both access points depicted on 
the preliminary site plan will be gated. An internal 20-foot-wide access road will provide 
circulation around the battery enclosures for operation and maintenance purposes. The 
internal circulation plan is designed to facilitate efficient access for both operations 
teams and emergency response vehicles. 
 
6. 
Anticipated Development Schedule 
It is anticipated that Sierra Luna will begin operations with SRP in 2029. To meet this 
schedule, Applicant is targeting the following dates:  
• 2025: Maricopa County Zone Change and Overlay 
• 2025 : Maricopa County Plan of Development 
• 2027: Maricopa County Building Permit and Other Administrative Permits 
• 2028: Construction Mobilization 
• 2029: Commercial Operation 
 
7. 
Community Facilities and Services  
During operations, the Project will have no impact on community facilities and services 
such as schools and parks. After construction, BESS projects generate minimal additional 
roadway traffic and they do not place any burden on local schools, as they do not 
contribute to population growth or daily commuting demands. Please see Section 1 for a 
detailed discussion on emergency response services.  
 
8. 
Public Utilities and Services  
Sierra Luna will not create an undue burden on public facilities and will not require 
services beyond what is required for existing private electric utilities located in the area. 
The Project will utilize public roads to access the site. However, the bulk of transportation 
needs will take place during the construction phase of the project. Once operational, use

Sierra Luna Energy Storage 
Narrative Report  
Page 18 
May 9, 2025 
 
 
of City and County roads will resemble current traffic patterns in the area. Additionally, 
Sierra Luna will provide a net positive contribution to public utilities, enhancing grid 
stability and reliability without straining community resources. 
8.1 
Water and Sewer 
The Project will not require water or sewer for operation of the battery energy storage 
systems. The on-site trailer used by on-site workers will include bathroom facilities that 
will be serviced by a third-party contractor. Therefore, there is no need to connect to 
municipal sewer facilities or to connect to/provide water. To respond to a request from 
Rural Metro, the Applicant will construct and maintain a 24,000-gallon, above-ground 
water tank kept on site to aid Rural Metro’s response in the unlikely need for defensive 
operations during an emergency. This approach aligns with applicable fire code and is 
common for commercial and residential developments served by Rural Metro Fire 
Department. 
8.2 
Fire Protection Measures 
The Applicant recognizes that fire safety and suppression, as well as the priority safety of 
our first responders and Maricopa County citizens, are paramount to the County’s review 
and approval of the Project. The Project will comply with applicable local fire code, the 
NFPA 855 2023 version and the Occupational Safety Health Administration (“OSHA”) 
1926 standards, and the units installed will be certified by the Underwriters Laboratories 
under 9540A.  
The Project will be designed, constructed, and operated in a manner that will promote and 
maintain safety. The Project will utilize best-in-class lithium-ion battery products. These 
are non-occupiable structures that will meet safety and performance requirements for 
BESS technology described by NFPA and IFC and have undergone Underwriters 
Laboratory testing. Comprehensive evaluations from independent auditors, such as 
Fisher Engineering, demonstrate that the technology is well suited for the proposed site. 
The system will be designed to comply with the current IFC adopted by Maricopa County 
Ordinances. In particular, the stationary storage battery systems will comply with IFC 
Chapter 12. Sierra Luna Batteries will maintain a 100-foot setback from all property lines 
in compliance with NFPA 855 2023 and 2018 IFC.  
The BESS will be designed with active and passive safety features that enable constant 
monitoring of the Project on a single cell level every second of the day. The Battery 
Management System monitors key datapoints such as voltage, current, and temperature

Sierra Luna Energy Storage 
Narrative Report  
Page 19 
May 9, 2025 
 
 
of battery cells, in addition to providing control of corrective and protective actions in 
response to any abnormal conditions. To provide a redundant safety detection system, 
the Project may also be equipped with 24-hour infrared thermal detectors directed at the 
batteries. Moreover, the project will be monitored 24/7 by remote operating centers. As 
mentioned above, three to five employees will provide full-time operations and 
maintenance to ensure the BESS operates safely. 
The Sierra Luna Project Team met with Rural Metro Fire Department in November 2024 
and again in January 2025. The Applicant is working with Rural Metro to provide a “will 
serve” letter. Sierra Luna will continue to collaborate with Rural Metro to develop an 
Emergency Response Plan to be submitted to the County that specifically addresses site 
planning and emergency response. In addition, training will be provided to local first 
responders around the time of Project commissioning and re-training will be provided on 
an annual basis.  
Proposed Rezoning Case Stipulation Language Regarding Fire Authority Review 
To further ensure fire safety measures are secured for the Project, the Applicant is 
proactively requesting that County Staff include and require a stipulation as part of the 
rezone approval which provides express powers to Rural Metro to review and approve all 
plans prior to the issuance of building permits and any certificates of occupancy. The 
proposed stipulation language is as follows: 
Administrative approval of a POD will be required prior to approval and issuance of 
construction permits to develop and establish use of the site. Prior to issuance of a 
building permit, written confirmation will be required from the emergency fire 
protection jurisdiction having authority that the facility has been designed in 
accordance with their regulations and requirements, and that emergency fire 
protection service will be provided to the facility. Prior to issuance of the certificate of 
occupancy, local fire protection jurisdiction review and approval will be required.

Sierra Luna Energy Storage 
Narrative Report  
Page 20 
May 9, 2025 
 
 
9. 
IUPD Comparison Chart 
REGULATION 
BASE ZONING DISTRICT 
REGULATIONS (IND-2) 
PROPOSED ZONING DISTRICT 
REGULATIONS (IND-2 IUPD) 
Maximum Building Height   
40' 
40’ 
Minimum Front Yard   
20’ (abutting a section line road) 
20’ (abutting a section line road) 
except 100’ from battery enclosures 
to property line 
Minimum Side Yard   
5’ (adjacent to rural or residential 
zoning district) 
5’ (adjacent to rural or residential 
zoning district) except 100’ from 
battery enclosures to property line 
Minimum Street-side 
Yard   
10’ (street side of corner lot abutting 
rural residential zoning district) 
10’ (street side of corner lot abutting 
rural residential zoning district) except 
100’ from battery enclosures to 
property line 
Minimum Rear Yard   
25' (abutting a rural or residential 
zoning district) 
25' (abutting a rural or residential 
zoning district) except 100’ from 
battery enclosures to property line 
Minimum Lot Area   
6,000 sq. ft. 
6,000 sq. ft. 
Minimum Lot Width   
60' 
60' 
Maximum Lot Coverage   
60% 
60% 
Parking Spaces   
Office: 1 space per 250 SF 
Industrial: 1 space per 600 SF 
Office: 1 space per 250 SF 
Industrial: 3 spaces plus 1 ADA stall 
Perimeter Screening   
6’ masonry wall 
8’ masonry wall 
Additional Regulations  
Article 902.9.1. All uses except for 
parking, loading, unloading or 
storage shall be conducted within a 
completely enclosed building 
Battery Energy Storage Systems 
components may be located outside 
of enclosed buildings. 
Paving   
Article 1102.7.1. For other than one 
single-family dwelling unit or one 
mobile home on a lot of record, any 
parking area must be paved or in the 
alternative surfaced with aggregate 
base course material. 
Gravel surface with compacted 
subgrade of native soil. 
Battery Energy Storage is the only permitted use in the IUPD Overlay 
Setbacks: The Applicant seeks to increase the front, side, and rear yard setbacks to 100-
feet for added safety and aesthetics (i.e., screening for visual impacts) beyond MCZO 
requirements for the BESS. Using the 2023 version of NFPA 855 as it applies to remote

Sierra Luna Energy Storage 
Narrative Report  
Page 21 
May 9, 2025 
 
 
facilities, the site will have 100-foot setbacks from all battery enclosures and Project 
parcel lot lines.  
The Applicant also requests that these setback areas allow for drainage channels, 
perimeter walls, accessways, signage, or other improvements per the setbacks of the 
underlying IND-2 zoning district but excluding battery storage units.  
Loading and Unloading: The Applicant requests that no loading and unloading spaces be 
required for this Project. Once operational, the Project will have very few vehicle trips. 
Parking will be provided for the operation and maintenance facility per MCZO standards. 
Additional Regulations: The Applicant requests removal of the requirement for all uses 
except for parking, loading and unloading, or storage to be conducted within an enclosed 
building. Locating BESS components indoors will increase fire safety risks, and NFPA 
standards support locating BESS components outdoors within sealed containers that are 
separated from each other.  
Paving: The Applicant requests that alternative surfacing materials or methods approved 
by Maricopa County Air Quality may be used in driveways and parking areas. Gravel roads 
on the Project will be maintained to reduce fugitive dust in accordance with County air 
quality regulations and will be coordinated with the appropriate fire safety agency to 
ensure adequacy for emergency vehicle use. 
 
10. Comprehensive Plan Compliance 
10.1 County Comprehensive Plan Compliance  
The Sierra Luna BESS Project aligns with the Maricopa County Vision 2030 
Comprehensive Plan. Energy storage in the county is a technology that results in cost 
effective energy production and use and provides significant environmental benefits by 
allowing the integration of variable renewable generation resources while adding to the 
economy.  
“Maricopa County recognizes that technological innovation leads to cost effective 
energy production and use, which ultimately creates economic and environmental 
benefits.” Maricopa County Comprehensive Plan, page 101.  
The Energy section of the Maricopa County Comprehensive Plan underscores the 
County’s commitment to the development of innovative energy infrastructure uses,

Sierra Luna Energy Storage 
Narrative Report  
Page 22 
May 9, 2025 
 
 
particularly technologies with low water usage to avoid depleting groundwater resources. 
The Sierra Luna Energy Storage Project has no operational needs for water.  
The Maricopa County Comprehensive Plan also details a goal of being a leader in energy 
development. One way to do that is by enhancing grid resiliency through the 
implementation of battery energy storage solutions. 
10.2 City of Avondale 2030 General Plan 
The City of Avondale future land use map designates the Project area for medium-density 
residential development, with commercial development planned across Avondale 
Boulevard and to the south between the Property and Broadway Road. Medium-density 
residential development is also planned to the north and east. While the future land use 
map serves as a guide and is not parcel-specific, the Property faces challenges related to 
medium-density residential development due to the need to maintain open space for 
floodplain mitigation. However, the Project and associated unique design associated with 
a BESS development, can accommodate the necessary basins for floodplain mitigation. 
The Project is designed to minimize impacts on local land uses and resources, manage 
floodplain distribution responsibly, and blend with the surrounding area's aesthetics. The 
Saint John’s Canal to the north of the project and 113th Avenue make logical barriers to 
transition from the commercial uses along Avondale Boulevard to the planned residential 
to the north and east.  
10.3 Coordination with City of Avondale  
The Project team has been regularly meeting with City of Avondale staff – including the 
City Manager, Development Services, Engineering, and the Fire Chief to discuss the 
Project. Negotiations are ongoing regarding a potential agreement related to 
improvements along Avondale Boulevard. These improvements are of mutual interest to 
the City, County and Developer, and will enhance the aesthetics and ensure inter-
governmental alignment along an important transportation corridor. 
Avondale is a key partner in this development, not only due to our adjacency to the City’s 
boundaries, but also because the Project requires approval from the City of Avondale for 
the short interconnection line leading to the Rudd Substation. Building off positive 
relationships with operating Sierra Estella Energy Storage Project in Avondale, the 
Applicant will continue its coordination with City on permitting the proposed 
interconnection line and associated approval requirements. The interconnection line is

Sierra Luna Energy Storage 
Narrative Report  
Page 23 
May 9, 2025 
 
 
planned to cross Avondale Boulevard into the City of Avondale and run along the south 
side of the Hermosa Ranch PAD to the Rudd substation.  
10.4 Outreach and Community Participation Plan  
The Applicant takes community outreach and engagement seriously. From the beginning, 
the Project has prioritized meaningful dialogue with neighbors and key stakeholders, City 
of Avondale, economic development specialists, and SRP Water Division. In February of 
2025, the Applicant mailed out notification letters and hosted a Community Open House 
near the Property. The open house included project experts ready to answer questions 
and listen to concerns from members of the public and attending agencies. Members of 
the development team were located at various stations containing informational boards. 
Project information handouts were also made available. The handouts included the 
project website, email address and phone number making the project team available to 
answer questions and address concerns. No objections or complaints were received in 
advance of or at the open house.  The only attendee at the open house was a City of 
Avondale Planner, but no other members of the public attended. 
 
Sierra Luna Energy Storage will continue its work with the local community, both 
throughout the development period and for the life of the Project since we look forward to 
being a good neighbor for many years to come. The Project team also looks forward to 
continued collaboration with Maricopa County, the City of Avondale, and other 
governmental agencies. Per the MCZO, a citizen participation plan has been submitted 
as part of the zone change with overlay application. 
 
11. Other Project-Specific Information 
11.1 Battery Energy Storage System Detail 
The Project will have modular electrical equipment composed of individual battery units 
or “racks,” housed in enclosed containers with integrated inverters. The batteries will be 
evenly spaced throughout the property following requirements for setbacks and spacing 
according to applicable code and manufacturer recommendations. The battery storage 
modules will be laid out in modular, orderly rows. Each grouping of approximately four 
battery containers will operate at low voltage (480 V) and be connected to a medium 
voltage (“MV”) 34.5-kV step-up transformer. The medium voltage transformers will be

Sierra Luna Energy Storage 
Narrative Report  
Page 24 
May 9, 2025 
 
 
connected in parallel to form a collector circuit, which will feed into the MV feeder bays of 
the Project substation. 
Sierra Luna can be operated and monitored remotely with a much smaller footprint than 
other energy infrastructure. This technology uses proven, reliable, and safe lithium-ion 
batteries that are preassembled for use in climate-controlled containers with redundant 
operating and safety systems. Each battery container unit will contain specially designed 
safety systems and remote controls that monitor battery temperature, voltage, and 
performance and enable redundant remote and manual shutdown capabilities. 
Over time, to maintain the Project’s energy storage capacity and efficiency throughout its 
lifetime, augmentation of the Project’s battery enclosures is necessary. Augmentation is 
the maintenance process of adding more battery energy storage capacity periodically to 
compensate for the natural degradation of the capacity of the BESS installed initially. This 
maintenance process is anticipated to include repair, replacement and installation of new 
battery enclosures. The equipment used for augmentation will generally be similar in 
function to the equipment installed during the initial construction phase and will be 
determined at the time of installation to utilize the state-of-the-art technology at that time.  
11.2 Project Substation 
An on-site substation for the Project will be built in the northwest portion of the Project 
footprint and will output electricity at 230-kV. Within the Project substation, there will be 
a concrete pads and other foundations for facilities including an electrical transformer, 
control enclosure, up to four lightning poles (static masts) approximately 100 feet in 
height, and a substation dead-end structure up to approximately 80 feet in height. Ground 
material at the site will consist primarily of crushed rock, resembling typical substations 
in the area. All electrical equipment will be designed in close communication with the 
interconnection engineers from SRP. 
The MV feeder bays will feed into a main power transformer, expected to be a three-phase, 
outdoor unit designed for stepping up the voltage to transmission levels. The main power 
transformer will be in the Project substation, which will also house one power pole/tower 
to raise an approximately 0.80-mile-long transmission line. Only a short portion of the line 
will be within unincorporated Maricopa County, while the remainder of the line running 
west from the site to the Rudd Substation will be within the City of Avondale.

Sierra Luna Energy Storage 
Narrative Report  
Page 25 
May 9, 2025 
 
 
11.3 Transmission Line 
An overhead 230-kV line will be installed to provide a connection to the existing Rudd 
Substation located approximately 0.80 mile to the west of the proposed Project site. The 
only portion of the transmission line included within this zone change and overlay request 
will be a short section of the line connecting the dead-end structure in the Project 
substation to a monopole located outside of the Project substation in the northwest 
corner of the project site. The transmission line will then travel off the western edge of the 
Project site across Avondale Boulevard and along an generally along an east-west 
easement to the Rudd substation. The monopoles supporting the 230-kV transmission 
line will likely be steel and approximately 80-120 feet above ground level. Finally, the 
existing Rudd Substation will be modified to allow for interconnection of the new 
transmission line into the substation. 
11.4 Experience and Nearby Projects 
The Applicant also developed, constructed, owns and operates the Sierra Estrella Energy 
Storage Project in Avondale, Arizona and the Superstition Energy Storage Project in the 
Town of Gilbert, Arizona. 
The Sierra Estrella Energy Storage Project interconnects adjacent to the 230-kV bus of the 
Rudd Substation, an existing critical exchange on the grid. That project, which began 
commercial operations in June 2024, holds up to 250 MW / 1,000 MWh of battery energy 
capacity, providing enhanced grid reliability and allowing the integration of low-cost, 
readily available energy into the local electrical system.  
The Superstition Energy Storage Project is adjacent to the existing 230-kV Corbell 
Substation. The 90 MW / 360 MWh battery storage facility provides capacity and energy 
services to the SRP electrical grid in southeast Phoenix, enhancing grid reliability and 
accelerating the integration of readily available, locally produced energy sources. This 
project began commercial operations in July 2024.  
 
12. Conclusion 
The Applicant respectfully requests review of this submittal for a zone change from RU-
43 to IND-2 with an IUPD overlay to accommodate a new BESS. The Sierra Luna Energy 
Storage Project will help optimize SRP’s energy use, provide tangible economic benefits

Sierra Luna Energy Storage 
Narrative Report  
Page 26 
May 9, 2025 
 
 
to the community, enhance regional grid reliability, require no public infrastructure, and 
be a good neighbor. 
If you have any questions regarding this request, please contact Christy Eichorn at 
ceichorn@pluspower.com or 480-685-9811. Thank you for your consideration.

APPENDIX A 
ZONING EXHIBIT 
Sierra Luna Energy Storage 
Narrative Report 
May 9, 2025

SITE
Zoning: RU-43
Zoning: RU-43
Zoning: 
Zoning: 
RU-43
RU-43
Zoning: RU-43
Zoning: RU-43
Zoning: RU-43
Zoning: RU-43
City of Avondale
City of Avondale
Zoning: RR-43
Zoning: RR-43
City of Avondale
City of Avondale
Zoning: PAD
Zoning: PAD
City of Avondale
City of Avondale
Zoning: PAD
Zoning: PAD
City of Avondale 
 Zoning: R1-6
City of Avondale 
 Zoning: R1-6
City of 
City of 
Avondale
Avondale
Zoning: 
Zoning: 
PAD
PAD
City of 
City of 
Avondale
Avondale
Zoning: 
Zoning: 
PAD
PAD
AVONDALE BOULEVARD
AVONDALE BOULEVARD
26 February 2025
N:\01\0426001\Graphics\Exhibits
Sierra Luna
Existing Zoning Map
0’
60’ 
120’

Zoning: 
Zoning: 
RU-43
RU-43
Zoning: RU-43
Zoning: RU-43
Zoning: RU-43
Zoning: RU-43
City of Avondale
City of Avondale
Zoning: RR-43
Zoning: RR-43
City of Avondale
City of Avondale
Zoning: PAD
Zoning: PAD
City of Avondale
City of Avondale
Zoning: PAD
Zoning: PAD
City of Avondale 
 Zoning: R1-6
City of Avondale 
 Zoning: R1-6
City of 
City of 
Avondale
Avondale
Zoning: 
Zoning: 
PAD
PAD
City of 
City of 
Avondale
Avondale
Zoning: 
Zoning: 
PAD
PAD
AVONDALE BOULEVARD
AVONDALE BOULEVARD
SITE
Zoning: IND-2 IUPD
Zoning: IND-2 IUPD
26 February 2025
N:\01\0426001\Graphics\Exhibits
Sierra Luna
Proposed Zoning Map
0’
60’ 
120’

APPENDIX B 
CHANGE OF ZONE LEGAL DESCRIPTION 
Sierra Luna Energy Storage 
Narrative Report 
May 9, 2025

Sierra Luna Energy Storage 
Narrative Report 
May 9, 2025 
 
 
 
 
 
 
 
 
 
 
APPENDIX C 
SRP TEN YEAR TRANSMISSION PLAN

Page1 
Page1
 
 
 
 
 
2018 
Prepared for the Arizona Corporation Commission 
January 2018 
Docket No. E-00000D-17-0001  
 
SRP Ten Year Transmission Plan 
2018-2027

SRP Ten Year Transmission Plan 2018-2027 
i 
 
Table of Contents 
 
1. Introduction ......................................................................................................................... 1 
2. Planning Organizations ...................................................................................................... 2 
2.1 
Regional Planning Organizations ................................................................................. 2 
2.1.1 Western Electricity Coordinating Council (WECC) ............................................ 2 
2.1.2 WestConnect .................................................................................................... 2 
2.2 
Subregional Planning Group ........................................................................................ 3 
2.2.1 Southwest Area Transmission (SWAT) ............................................................. 3 
3. Biennial Transmission Assessment (BTA) Order Requirements ..................................... 4 
3.1 
9th BTA Order Requirements ....................................................................................... 4 
3.2 
Prior BTA Order Requirements .................................................................................... 4 
4. SRP Ten Year Transmission Plan Study Work .................................................................. 6 
5. Changes from Previous Plan .............................................................................................. 7 
5.1 
Projects Placed in Service in 2017 ............................................................................... 7 
5.2 
Revised Projects .......................................................................................................... 7 
5.3 
New Projects ................................................................................................................ 7 
5.4 
Removed Projects ........................................................................................................ 7 
5.5 
Potential Projects ......................................................................................................... 7 
6. Project Maps ........................................................................................................................ 9 
6.1 
Figure 1 – SRP 500kV System ................................................................................... 10 
6.2 
Figure 2 – SRP 230kV System West .......................................................................... 11 
6.3 
Figure 3 – SRP 230kV System East ........................................................................... 12 
6.4 
Figure 4 – SRP 115kV System (Eastern Mining Area) ............................................... 13 
7. Project Descriptions ......................................................................................................... 14 
7.1 
Browning – Corbell 230kV & Santan – Rogers 230kV Line Reconfiguration (2019) ... 15 
7.2 
Coolidge – Hayden 115kV Reroute (2020) ................................................................. 16 
7.3 
SunZia Southwest Transmission 500kV Project (2021) .............................................. 17 
7.4 
Price Road Corridor (2021) ........................................................................................ 18 
7.5 
Abel – Pfister – Ball 230kV (2021-TBD) ..................................................................... 19 
7.6 
Copper Crossing – Abel 230kV (2023) ....................................................................... 20 
7.7 
Southeast Power Link (2024) ..................................................................................... 21 
7.8 
Hassayampa – Pinal West 500kV #2 Line (2024) ...................................................... 22 
7.9 
Silver King – New Oak Flat – New Superior 230kV (2026) ......................................... 23 
7.10 Superior – Silver King 115kV Reroute (2027) ............................................................. 24 
8. Attachment ........................................................................................................................ 25 
8.1 
Attachment 1 – 2018 Ten Year Plan Technical Study ................................................ 25

SRP Ten Year Transmission Plan 2018-2027 
Page 1 of 25 
 
1. Introduction 
 
This report updates and replaces the Ten Year Transmission Plan of the Salt River Project 
Agricultural Improvement and Power District (SRP), submitted in January 2017 pursuant to 
A.R.S. Section 40-360.02 - Plans; filing; failure to comply; classification. The 2018-2027 plan 
describes planned transmission line projects of 115kV or higher that SRP may construct or 
participate in over the next ten years.

SRP Ten Year Transmission Plan 2018-2027 
Page 2 of 25 
 
2. Planning Organizations 
 
SRP continues to be involved in regional and subregional planning organizations. SRP’s 
primary goal in these various planning activities is to ensure that a reliable and economical 
transmission system is connected to energy sources. Participation also allows SRP to 
coordinate its transmission plans with the plans of the other transmission providers.  
 
2.1 Regional Planning Organizations 
 
2.1.1 Western Electricity Coordinating Council (WECC) 
 
WECC is a non-profit corporation approved by the Federal Energy Regulatory 
Commission (FERC) to serve as the Regional Entity tasked with assuring a reliable 
bulk electric system in the geographical area known as the Western 
Interconnection. 
 
SRP is an active participant in the WECC committees that develop and integrate 
new system and generation models, develop WECC-wide base cases, develop 
WECC reliability criteria, and coordinate planning methodologies.  
 
2.1.2 WestConnect 
 
SRP participates in the regional transmission planning activities of WestConnect. 
WestConnect is comprised of utility companies and independent transmission 
developers with transmission assets or potential transmission projects in the 
western United States. Its members collaboratively assess stakeholder needs and 
develop cost-effective transmission enhancements. WestConnect is committed to 
coordinating its work with other regional and interregional industry efforts to ensure 
consistency within the Western Interconnection.  
 
SRP continues to be an active participant in the WestConnect regional 
transmission planning and cost allocation processes established by FERC Order 
No. 1000. In August 2016, the 5th Circuit Court of Appeals vacated FERC’s 
Compliance Orders on the WestConnect Order 1000 process. The WestConnect 
utilities continue to work through the regional transmission planning process while 
they wait for FERC to reassess the compliance orders. While SRP is not required 
to participate in the Order No. 1000 process, SRP recognizes the importance of 
maintaining a collaborative and cooperative transmission planning process in the 
Western Interconnection. The Order No. 1000 planning process began January 1, 
2015 with an abbreviated, one-year planning cycle. The regular, biennial regional 
transmission planning process began January 1, 2016. The outcome of Order No. 
1000 regional transmission planning is a regional transmission plan that selects 
regional transmission projects to meet identified reliability, economic, or public

SRP Ten Year Transmission Plan 2018-2027 
Page 3 of 25 
 
policy transmission needs. The regional participants did not identify any 
transmission needs in the 2016–2017 Regional Transmission Plan.1 
 
2.2 Subregional Planning Group 
 
2.2.1 Southwest Area Transmission (SWAT) 
 
The SWAT Subregional Planning Group addresses future transmission needs on a 
subregional (desert southwest) basis. SRP participates in SWAT activities to help 
meet obligations for the Arizona Corporation Commission (ACC) and the Ten Year 
Transmission Plan filing. SWAT disseminates its work publicly and coordinates its 
studies and data with other subregional planning groups and WestConnect. 
                                                          
1 WestConnect 2017 Regional Transmission Plan is available at: 
https://doc.westconnect.com/Documents.aspx?NID=17160

SRP Ten Year Transmission Plan 2018-2027 
Page 4 of 25 
 
3. Biennial Transmission Assessment (BTA) Order Requirements 
 
3.1 9th BTA Order Requirements 
 
On November 21, 2016, the ACC issued Decision No. 75817, which suspended the 
requirement from the 8th BTA that required utilities to provide the anticipated load level 
range at which each transmission project may be needed. Consistent with the 8th BTA, 
utilities must continue to describe whether each project is driven by load growth or 
reliability. Factors driving each of SRP’s transmission projects may change over time as 
resource plans change.  
  
3.2 Prior BTA Order Requirements  
 
The following sections highlight SRP’s responses to ongoing activities related to prior BTA 
orders.  
 
As ordered by the ACC in its 7th BTA decision, entities are required to notify parties 
requesting generation or transmission interconnections to the Bulk Electric System of the 
appropriate ACC filing requirements. SRP placed an advisory notice on SRP’s OASIS 
page on March 19, 2013 to satisfy this requirement:  
 
http://www.oatioasis.com/SRP/SRPdocs/Potential_Additional_State_Requirements.pd.pdf 
 
This notice continues to meet the requirements of the 7th BTA that was further affirmed in 
the 8th and 9th BTAs. SRP does not take responsibility for any third-party interconnector’s 
compliance with ACC requirements. 
 
The ACC’s 6th BTA order adopted several requirements that remain in force. The ongoing 
requirements include: 
 
a) Report relevant findings in future BTAs regarding compliance with transmission 
planning standards (e.g. TPL-001 through TPL-004)2 from NERC/WECC 
reliability audits that have been finalized and filed with FERC. 
 
SRP was last audited on its compliance with NERC Standards TPL-001-0, TPL-
002-0, and TPL-003-0 in August 2013. The WECC Audit team determined that 
SRP is in compliance with these three Standards. The next audit of TPL-001-4 
has not been scheduled.  
 
b) Identify planned transmission reconductor projects, transformer capacity upgrade 
projects, and reactive power compensation facility additions at 115kV and above 
in ten year plan filings.  
 
                                                          
2 NERC Standards TPL-001 through TPL-004 have been replaced with TPL-001-4.

SRP Ten Year Transmission Plan 2018-2027 
Page 5 of 25 
 
SRP’s planned transmission reconductor, transformer capacity upgrades, and 
reactive power compensation additions in this ten year period are shown below. 
In-service dates may change to reflect load changes in the local system.  
 
Reactive Devices 
SRP’s planned reactive device addition and anticipated in-service year: 
• 
18 Ohm Series Reactors on Palo Verde – Hassayampa 500kV Ties #1-3 
(2020) 
 
Transformers 
SRP’s planned transformer additions to existing stations to accommodate load 
growth and anticipated in-service year: 
• 
Rudd 230/69kV Transformer (2022) 
• 
Browning 230/69kV Transformer (2024)  
 
Reconductor 
SRP does not have any planned reconductor projects. 
 
c) Discuss the effects of distributed renewable generation and energy efficiency 
programs on future transmission needs in ten year plan filings. 
 
SRP includes the effects of energy efficiency programs and distributed 
generation (traditional and renewable) in its resource planning and transmission 
system models. Thus, each of the transmission projects identified in the Ten 
Year Transmission Plan includes the effects of energy efficiency and distributed 
generation. In addition, the 8th BTA (Decision No. 74785, dated October 24, 
2014) called for a technical study to analyze the effects of removing DG and EE. 
To comply with this order, SRP is analyzing the effects of DG and EE through a 
separate study that will be reported for the upcoming 10th BTA.

SRP Ten Year Transmission Plan 2018-2027 
Page 6 of 25 
 
4. SRP Ten Year Transmission Plan Study Work 
 
Attachment 1 contains the 2018 Ten Year Transmission Plan Technical Study. This study 
analyzed the reliability impacts of the projects identified in the Ten Year Transmission Plan. 
Study work for joint projects is covered by subregional planning groups.

SRP Ten Year Transmission Plan 2018-2027 
Page 7 of 25 
 
5. Changes from Previous Plan 
 
The following changes are noted between the Ten Year Transmission Plan submitted in 
January 2017 and this submittal. The changes include project or substation names, in-service 
dates, projects now in service, and newly identified projects.  
 
5.1 Projects Placed in Service in 2017 
 
SRP’s placed the following projects in service in 2017: 
• 
12 Ohm Series Reactors on Palo Verde – Hassayampa 500kV Ties #1-3 
 
5.2 Revised Projects 
 
Revised Project 
2017 Plan 
2018 Revision 
Price Road Corridor 
2019 – TBD 
2021 – TBD 
Southeast Power Link 
2019 
2024 – TBD 
“Mesa Technology 
Corridor” 
“Southeast Power 
Link” 
Copper Crossing – Abel 230kV 
2021 
2023 
Superior – Silver King 115kV Reroute 
2017 
2027 
 
5.3 New Projects  
 
SRP did not add any new projects.  
 
5.4 Removed Projects 
 
SRP did not remove any projects. 
 
5.5 Potential Projects 
 
The following projects were included in previous plans with TBD in-service dates and have 
not advanced in SRP’s planning process. In order to provide further transparency, SRP 
will continue to reflect these and other projects under consideration that fall outside of the 
ten year planning window as “Potential Projects” in future filings.

SRP Ten Year Transmission Plan 2018-2027 
Page 8 of 25 
 
Potential Project
Purpose
Eastern Mining Expansion 
Accommodate growing mining customer load in 
SRP’s Eastern Mining Area. 
Superior 230kV Loop-in 
Provide adequate transmission capacity in the 
event of future load growth in SRP’s eastern 
service territory. 
Thunderstone – Browning 230kV 
Provide additional transfer capability from the 
south and east to the north and central areas of 
SRP’s service territory. 
Silver King – Knoll – New Hayden 
230kV 
Increase the transmission capacity to serve new 
customer load in SRP’s eastern service territory. 
New Hayden 115kV Loop-in 
Increase the transmission capacity to serve new 
customer load in SRP’s eastern service territory. 
RS25 Project 
Serve growing Salt River Pima – Maricopa Indian 
Community load. 
RS26 Project 
Serve load growth in the Fountain Hills area and 
to relieve stress on the lower voltage system that 
serves the Fountain Hills/Rio Verde area. 
Pinal Central – Abel – RS-20 500kV 
Deliver remote resources into the southeast 
portion of SRP’s service territory. 
Palo Verde – Saguaro 500kV 
Increase the adequacy of the existing EHV 
transmission system and permit increased power 
delivery throughout the state. 
Ball (RS17) 230kV Loop-in 
Serve customer load in the Gilbert/Queen Creek 
area. 
Pinnacle Peak – Brandow 230kV 
Provide adequate transmission capacity to 
accommodate SRP customer load. 
Abel 500kV Substation 
Provide adequate transmission capacity for future 
load growth.

SRP Ten Year Transmission Plan 2018-2027 
Page 9 of 25 
 
6. Project Maps 
 
This section includes maps showing the general location of existing and future transmission 
projects. Substation locations and line routings depict an electrical connection only and do not 
reflect any assumed physical locations or routing. Separate maps are provided for the 500kV 
system (Figure 1), the 230kV System West (Figure 2), the 230kV System East (Figure 3), and 
the 115kV system (Figure 4). The 115kV map primarily covers the 115kV Eastern Mining Area 
of SRP’s service territory; however, some 230kV projects are also included.

SRP Ten Year Transmission Plan 2018-2027 
Page 10 of 25 
 
 
6.1 Figure 1 – SRP 500kV System  
 
 
Substation locations 
and line routings depict 
an electrical connection 
only and do not reflect 
any assumed physical 
locations or routing.

SRP Ten Year Transmission Plan 2018-2027 
Page 11 of 25 
 
6.2 Figure 2 – SRP 230kV System West 
 
Substation locations and 
line routings depict an 
electrical connection only 
and do not reflect any 
assumed physical locations 
or routing.

SRP Ten Year Transmission Plan 2018-2027 
Page 12 of 25 
 
6.3 Figure 3 – SRP 230kV System East  
 
 
Substation locations 
and line routings depict 
an electrical connection 
only and do not reflect 
any assumed physical 
locations or routing.

SRP Ten Year Transmission Plan 2018-2027 
Page 13 of 25 
 
6.4 Figure 4 – SRP 115kV System (Eastern Mining Area)   
 
Substation locations 
and line routings depict 
an electrical connection 
only and do not reflect 
any assumed physical 
locations or routing.

SRP Ten Year Transmission Plan 2018-2027 
Page 14 of 25 
 
 
7. Project Descriptions 
 
This section includes project details in accordance with the requirements of A.R.S. Section 40-
360.02 - Plans; filing; failure to comply; classification. Each project is identified by name, 
estimated in-service date, sizing details, routing, purpose, and major milestone dates.

SRP Ten Year Transmission Plan 2018-2027 
Page 15 of 25 
 
7.1 Browning – Corbell 230kV & Santan – Rogers 230kV Line 
Reconfiguration (2019)    
 
Size 
 
Browning – Corbell 
Santan – Rogers 
Voltage 
230kV 
230kV 
Capacity 
To be determined 
To be determined 
Point of Origin 
Browning 230kV Substation 
SEC 12, T1S, R7E 
Santan 230kV Substation 
SEC 21, T1S, R6E  
Intermediate Point 
NA 
NA 
Point of Termination 
Corbell 230kV Substation 
SEC 10, T1S, R5E 
Rogers 230kV Substation 
SEC 13, T1N, R5E 
Length 
Approximately 130 feet 
Approximately 70 feet 
Routing 
 
The Browning – Corbell line reconfiguration will follow the current route of the Browning – 
Santan and Santan – Corbell 230kV lines. The Santan – Rogers line reconfiguration will 
follow the current route of the Santan – Thunderstone 230kV line. This project will use 
existing circuit positions on existing structures. Reconfiguration of these two lines will be 
done in tandem. 
Purpose 
 
To create a third 230kV circuit serving the Corbell 230/69kV substation and prevent the 
loss of the Corbell 69kV area in the event of multiple 230kV line outages. This is a 
reliability driven project and is not triggered by rising system load levels forecasted in the 
next ten years. 
Schedule  
Right of Way / 
Property Acquisition 
NA 
Construction Start 
2018 
Estimated In-Service  
2019 
Notes 
 
The in-service year for this project advanced from 2020 to 2019 to coincide with other 2019 
projects that mitigate short circuit fault current issues at Kyrene 230kV. Together, the 
projects mitigate short circuit problems without causing any thermal overloads on the 
system. A CEC is not expected to be needed at this time.

SRP Ten Year Transmission Plan 2018-2027 
Page 16 of 25 
 
7.2 Coolidge – Hayden 115kV Reroute (2020) 
 
Size 
Voltage 
115kV 
Capacity 
To be determined 
Point of Origin 
Coolidge 115kV Substation 
SEC 16, T1S, R13E 
Intermediate Point 
None 
Point of Termination 
N/A this is a reroute of an intermediate portion of the line. 
SEC 16, T1S, R13E 
Length 
Approximately 1.5 miles 
Routing 
 
The portion of the line that may be relocated begins about 0.5 miles northeast of the 
Coolidge substation and runs north along the Union Pacific Railroad until it crosses the Gila 
River where it turns northeast following a canal and drainage feature. The portion to be 
rerouted is 1.25 miles in length. The new line will be from 1.25 to 2.0 miles long.  
Purpose 
 
A short segment of the subject 115kV line is located on Gila River Indian Community 
(GRIC) land. SRP is negotiating an extension of the current land grant for the line. SRP 
may elect to move this portion of the line onto private land if negotiations with the GRIC are 
unsuccessful or if SRP determines it is in the best interest of its customers. 
Schedule  
Right of Way / 
Property Acquisition 
2019 
Construction Start 
2020 
Estimated In-Service  
2020 
Notes 
 
SRP plans to pursue a CEC for this project in 2018 if negotiations with the GRIC are 
unsuccessful. SRP will begin the relocation of the impacted portion of the line once a 
certificate is received.

SRP Ten Year Transmission Plan 2018-2027 
Page 17 of 25 
 
7.3 SunZia Southwest Transmission 500kV Project (2021) 
 
Size 
Voltage 
Two single-circuit 500kV AC lines 
Capacity 
WECC Approved Rating of 3000MVA 
Point of Origin 
Central New Mexico 
Intermediate Point 
Willow 500kV Substation 
Point of Termination 
Pinal Central 500kV Substation 
SEC 30, T6S, R8E 
Length 
515 miles 
Routing 
 
From Lincoln County area in central New Mexico to the Willow 500kV substation 15 miles 
north of Bowie, Arizona to Pinal Central 500kV substation in Coolidge, Arizona.  
Purpose 
 
SRP’s interest in this project is to provide the opportunity to develop additional 
transmission from existing generation sources in eastern Arizona and western New Mexico 
to serve load in central Arizona. 
Schedule  
Right of Way / 
Property Acquisition 
In progress 
Construction Start 
To be determined 
Estimated In-Service 
2021 
Notes 
 
Southwestern Power Group is the project manager on the development of this project. 
SRP is a participant.

SRP Ten Year Transmission Plan 2018-2027 
Page 18 of 25 
 
7.4 Price Road Corridor (2021) 
 
Size 
Voltage 
230kV  
Capacity 
To be determined 
Point of Origin 
Knox 230kV Substation 
SEC 32, T1S, R4E 
Intermediate Point 
None       
Point of Termination 
New Henshaw 230kV Substation 
SEC 7, T2S, R5E 
Length 
Approximately 7 miles 
Routing 
 
The final line route was determined through the CEC process. The project consists of a 
new double circuit 230kV line from the existing Knox Substation to the new Henshaw 
Substation. Henshaw will be located near to the intersection of Price Road and Germann 
Road in Chandler.  
Purpose 
 
To serve growing industrial and commercial customer loads along the Price Road Corridor, 
adjacent to Price Road in Chandler. 
Schedule  
Right of Way / 
Property Acquisition 
2018-2019 
Construction Start 
Mid 2019 
Estimated In-Service 
2021:  Knox – Henshaw 230kV Line 
2021:  Henshaw 230kV Substation 
Notes 
 
SRP received a CEC for this project by unanimous approval by the Arizona Corporation 
Commission line siting committee on September 12, 2017 Case No.00175, Decision # 
76371. The CEC expires in September 2027.

SRP Ten Year Transmission Plan 2018-2027 
Page 19 of 25 
 
7.5 Abel – Pfister – Ball 230kV (2021-TBD)    
Size 
 
Voltage 
230kV 
Capacity 
To be determined 
Point of Origin 
Santan – Schrader 230kV Line 
(near existing Moody 69kV substation and future Ball (RS-17) 
230kV substation) 
SEC 1, T2S, R6E  
Intermediate Point 
New Pfister (RS-24) 230kV Substation 
SEC 25, T2S, R7E 
Point of Termination 
Abel 230kV Substation 
SEC 19, T3S, R9E 
Length 
Approximately 20 miles 
Routing 
 
This project is a double circuit 230kV line that bisects and connects the existing Santan – 
Schrader 230kV line #2 to Abel 230kV Substation. The new double circuit 230kV line will 
be routed generally south and east from a point on the Santan – Schrader 230kV line near 
the existing Moody 69kV substation and future Ball (RS-17) 230kV substation to the new 
Pfister (RS-24) 230kV substation in the southeastern portion of the town of Queen Creek. 
From the Pfister 230kV substation, the 230kV line will continue south and east to the Abel 
230kV substation.  
Purpose 
 
This project was originally proposed to serve long-term load growth in the southeast valley. 
Load growth remains a driver for this project. However, the current timeline reflects a near-
term reliability need driven by new generation resources connecting near Abel Substation.  
Schedule  
Right of Way/ 
Property Acquisition 
2013-2020 
Construction Start 
2019-2020 
Estimated In-Service 
2021:  Abel – Santan 230kV Line 
2021:  Abel – Schrader 230kV Line 
TBD:  Pfister 230kV Substation 
TBD:  Ball 230kV Substation 
Notes 
 
This project was formerly known as Abel – Moody. SRP received a CEC for this project on 
December 23, 2009, Case No. 148, Decision # 71441. The CEC expires December 23, 
2021. The Pfister 230kV and Ball 230kV substations in-service dates are TBD depending 
on load growth in the Queen Creek area.

SRP Ten Year Transmission Plan 2018-2027 
Page 20 of 25 
 
7.6 Copper Crossing – Abel 230kV (2023) 
 
Size 
Voltage 
230kV 
Capacity 
To be determined 
Point of Origin 
New Copper Crossing Energy Center 
SEC 24, T3S, R8E 
Intermediate Point 
NA 
Point of Termination 
Abel 230kV Substation 
SEC 19, T3S, R9E 
Length 
Less than 1 mile 
Routing 
 
This project is a double circuit 230kV line to connect new generation units to Abel 230kV 
substation.  
Purpose 
 
To accommodate near term new generation resources connecting in the Abel area. This is 
a reliability driven project and is not triggered by rising system load levels forecasted in the 
next ten years. 
Schedule  
Right of Way / 
Property Acquisition 
NA 
Construction Start 
2023-2024 
Estimated In-Service 
2023: Copper Crossing Energy Center – Abel 230kV Line #1 
2024: Copper Crossing Energy Center – Abel 230kV Line #2 
 
Notes 
 
If the installed generation capacity is over 925 MW, a new 230kV switchyard will need to 
be built near Abel Substation in order to limit the amount of generation loss from a single 
contingency.

SRP Ten Year Transmission Plan 2018-2027 
Page 21 of 25 
 
7.7 Southeast Power Link (2024) 
 
Size 
Voltage 
230kV 
Capacity 
To be determined 
Point of Origin 
Section of Santan – Browning 230kV Line 
SEC 9, T1S, R7E 
Intermediate Point 
RS-31 230kV Substation 
TBD 
Intermediate Point 
RS-32 230kV Substation (if needed) 
TBD 
Point of Termination 
Section of Abel – Pfister – Ball 230kV Line 
SEC 10, T2S, R7E 
Length 
TBD 
Routing 
 
Several options are under consideration to accommodate potential southeast valley load 
growth in the City of Mesa and the Town of Queen Creek. The analysis indicates that 
adding one or two new 230kV substations and a connection between the existing Santan – 
Browning corridor to the future Abel – Pfister – Ball corridor would provide the greatest 
benefit to the area.  
 
The location of the 230kV substations and any new lines will be determined by the public 
siting process and load growth in the area. 
Purpose 
 
To meet potential growing customer loads in the southeast valley. 
Schedule  
Right of Way / 
Property Acquisition 
2019 
Construction Start 
2022 
Estimated In-Service 
2024 
Notes 
 
SRP does not yet hold a CEC for this project but plans to begin pursuing one in 2018. 
Construction of the facilities will be dependent upon the load growth in this area. This 
project was formerly identified as the Mesa Technology Corridor.

SRP Ten Year Transmission Plan 2018-2027 
Page 22 of 25 
 
7.8 Hassayampa – Pinal West 500kV #2 Line (2024)   
 
Size 
Voltage 
500kV 
Capacity 
TBD 
Point of Origin 
Hassayampa 500kV Switchyard 
SEC 15, T1S, R6W 
Intermediate Point 
Jojoba 500kV Switchyard 
SEC 25, T2S, R4W 
Point of Termination 
Pinal West 500kV Switchyard 
SEC 18, T5S, R2E 
Length 
Approximately 51 miles 
Routing 
 
South and east of the Hassayampa Switchyard along the existing Palo Verde – Kyrene 
500kV line to a point where the gas pipeline splits from the transmission line, then 
generally along the pipeline (except in the Maricopa County Mobile Planning Area) to the 
Pinal West 500kV switchyard. 
Purpose 
 
The Central Arizona Transmission System study identified system additions to provide 
access to new generation in western or central Arizona.  
 
This project is needed as a result of the EPA ruling on Section 111(d) of the Clean Air Act 
(October 23, 2015), establishing emission performance rates representing the best system 
of emission reduction. 
 
This project can accommodate increased access to existing and potentially new load 
growth; however, future load growth was not identified as a driver.  
 
This is a reliability driven project not triggered by system load forecasts within the next ten 
years. 
Schedule  
Right of Way / 
Property Acquisition 
2004 
Construction Start 
2023 
Estimated In-Service 
2024 
Notes 
 
The CEC for Case No. 124 was awarded in May 2004 (ACC Decision # 67012). The CEC 
expires May 24, 2024. The first of the two permitted transmission lines was placed in 
service in October 2008.

SRP Ten Year Transmission Plan 2018-2027 
Page 23 of 25 
 
7.9 Silver King – New Oak Flat – New Superior 230kV (2026) 
 
Size 
Voltage 
230kV 
Capacity 
To be determined 
Point of Origin 
Silver King 230kV Substation 
SEC 16, T1S, R13E 
Intermediate Point 
New 230kV Substation near the existing Oak Flat 115kV 
Substation, tentatively named “New Oak Flat” 
Near SEC32, T1S, R13E (exact location not determined) 
Point of Termination 
New 230kV Substation near the existing Goldfield – Silver King 
230kV line, tentatively named “New Superior” 
Near SEC34, T1S, R12E (exact location not determined) 
Length 
Approximately 6.5 miles 
Routing 
 
The alignment will closely follow the existing 115kV circuit connecting Silver King to Oak 
Flat. The line starts at the Silver King Receiving Station, heading south and then turning 
southwest into the New Oak Flat 230kV Substation. The alignment will then traverse to the 
west into the New Superior 230kV Substation. In addition, the existing Goldfield – Silver 
King 230kV line will be looped into the New Superior 230kV Substation. The location of the 
New Oak Flat and the New Superior sites are still being determined. 
Purpose 
 
To serve growing customer loads at Oak Flat and Superior. 
Schedule  
Right of Way / 
Property Acquisition 
N/A 
Construction Start 
2024 
Estimated In-Service 
2026 
Notes 
 
SRP does not yet hold a CEC for this project. SRP will pursue a Certificate when required 
by load growth in this area.

SRP Ten Year Transmission Plan 2018-2027 
Page 24 of 25 
 
7.10 Superior – Silver King 115kV Reroute (2027) 
 
Size 
Voltage 
115kV 
Capacity 
Approximately 165MVA 
Point of Origin 
Point on existing Superior – Silver King 115kV Line 
SEC 34, T1S, R12E 
Intermediate Point 
None 
Point of Termination 
Point on existing Superior – Silver King 115kV Line 
SEC 26, T1S, R12E 
Length 
Approximately 1.25 miles 
Routing 
 
The new alignment will traverse to the north and west of the historical line and adjacent to 
the existing Goldfield – Silver King 230kV circuit. 
Purpose 
 
To move an existing 115kV line on a single Customer’s private property to accommodate 
Customer’s land use needs. This is a single customer driven and requested project and is 
not triggered by system load growth. 
Schedule  
Right of Way / 
Property Acquisition 
None 
Construction Start 
2027 
Estimated In-Service 
2027 
Notes 
 
SRP was granted a CEC for Case No. 166 on October 4, 2012 (Decision # 73551) which 
expired in 5 years (October 16, 2017). An extension to the CEC termination date was 
submitted in July 2017. If approved, the CEC will be extended through 2027. The actual 
timing of the 115kV line relocation is dependent upon the Customer’s land use needs.

SRP Ten Year Transmission Plan 2018-2027 
Page 25 of 25 
 
 
8. Attachment 
 
8.1 Attachment 1 – 2018 Ten Year Transmission Plan Technical Study

Page 1 of 2 
 
 
 
 
 
 
 
 
 
 
 
James Philbin, PE 
Planning & Development 
301 W. Jefferson St., Suite 170 
Phoenix, Arizona 85003 
Phone: (602) 372-4362 
www.maricopa.gov/planning 
Email address: 
james.philbin@maricopa.gov 
Planning & Development 
 
Engineering Plan Review 
Date:    
March 21, 2025 
 
Memo To: Darren Gerard, AICP, Planning Manager, Department of Planning & 
Development 
 
Attn: 
Joel Landis, Planner, Planning & Development Services 
 
 
From: 
James Philbin, P.E., Plans Examiner Engineer, Planning & 
Development Services 
 
cc: 
Bob Fedorka, P.E., Engineering Manager, Planning & Development 
 
Subject:   
Z250007 - Zone Change (RU-43 to IND-2 IUPD) 
 
(E1 Memo) 
Job Site Address: 4025 Avondale BLVD, Tolleson, AZ 85353 
 
APN(s): 101-23-002F, 101-23-012E, 101-23-012D and 101-23-012C 
 
This application is to specify zoning for future development and does not include a 
Plan of Development. 
 
PND Engineering Plan Review (DPR, FCD and PND Transportation) has reviewed the 
1st submittal of the Zone Change application routed for review on March 03, 2025, and 
has no objections subject to the following conditions: 
 
1. Without the submittal of a precise plan of development, no development approval 
is inferred by this review, including, but not limited to number of proposed building 
lots/units, drainage design, access and roadway alignments. These items will be 
addressed as development plans progress and are submitted to the County for 
further review and/or entitlement. 
 
2. The site contains areas of regulated floodplains (FEMA Zone AE). 
 
3. Any Development in the floodplain will require a floodplain use permit issued 
concurrent with building permit(s) required for site development. Structures and 
pad elevations for battery storage units and other electrical equipment in the 
floodplain must be elevated to the regulatory flood elevation (BFE +2’) as 
determined by the engineer. (FRMC 601(A)4) 
 
4. The impact of the extensive quantity of fill in the floodplain will require analysis to 
determine its impact on the current floodplain delineations. Development of the 
site for the intended use may require re-delineation of the floodplain through the 
FEMA CLOMR/LOMR process (administered through the Flood Control District).

Page 2 of 2 
  
For more information on this process, please contact the Flood Control District 
Fahmida.Maula@maricopa.gov.   
 
Regulatory flood elevations remain effective until such time that LOMRs become  
effective. 
 
Note that a CLOMR has been filed for the subdivision located northeast of the 
subject premises. 
 
5. See  Tres Rios Vol. 1 and Tres Rios Vol. 2    for information regarding the Tres 
Rios North Levee FDS. 
 
6. Currently, the 113th Avenue alignment  is comprised of a series of private 
easement(s) that has not been accepted by the County; and is therefore not 
maintained by the County. It is the owner/applicant’s responsibilities to determine 
access rights to 113th Avenue. 
 
7. A Traffic Study/Statement must be submitted with future entitlement (POD) 
application(s). See following link to MCDOT Traffic Impact Manual. (RDM 7.1.4) 
https://www.maricopa.gov/DocumentCenter/View/303   
 
8. Given the anticipated low traffic volume and lack of frontage on County Road(s), 
the applicant can seek to have the Study requirement waived through the 
MCDOT Traffic Branch (Hasina Luna – Hasina.Luna@maricopa.gov). A copy of 
the waiver must be provided with the entitlement application. 
 
9. Avondale Boulevard and Broadway Road (at 113th Avenue) are within the 
jurisdiction of the City of Avondale. The applicant will be responsible for 
coordinating with the City to review any traffic impact, right-of-way dedication, 
permitting or roadway improvement requirements. 
 
 
10. Engineering review of re-zone cases is conceptual in nature. All development and 
engineering design shall be in conformance with Section 1205 of the Maricopa 
County Zoning Ordinance; Drainage Policies and Standards; Floodplain 
Regulations for Maricopa County; MCDOT Roadway Design Manual; and current 
engineering policies, standards and best practices at the time of application for 
construction. 
 
Please contact me if you have any questions or require any additional information.

Arizona Chamber of Commerce & Industry  
602.248.4430    100 N 7th Ave #120, Phoenix, AZ 85007 
 
 
May 9, 2025 
 
 
Subject: Letter of Support for Sierra Luna Energy Storage Project 
 
Dear Maricopa County Planning & Zoning Commissioners, 
On behalf of the Arizona Chamber of Commerce and Industry, I am writing to express our strong 
support for the Sierra Luna Energy Storage Project. The Arizona Chamber of Commerce and 
Industry is committed to fostering a pro-business environment that attracts investment, creates jobs, 
and enhances the quality of life for all Arizonans. We believe that the Sierra Luna project aligns with 
these goals and will be a valuable asset to our state's economy. 
A modern and reliable energy infrastructure is essential for attracting new businesses to Arizona and 
supporting the growth of our existing industries. Companies considering expanding or relocating to 
our state require assurance that they will have access to a stable and dependable power supply. The 
Sierra Luna project will play a crucial role in enhancing grid reliability, ensuring that Arizona can 
meet the energy demands of a growing and dynamic economy. 
Furthermore, the Sierra Luna project will contribute to the diversification of our state's energy 
portfolio. By supporting the integration of battery storage technology, this project will help Arizona 
become a leader in innovative energy solutions. This diversification is crucial for mitigating risks 
associated with reliance on any single energy source and for promoting long-term economic stability. 
The Sierra Luna project will also have a positive impact on local communities. During construction, 
the project will create jobs and stimulate economic activity in the region. Once operational, it will 
contribute to the local tax base, providing valuable resources for schools, infrastructure, and other 
essential services. 
We support responsible energy development that strengthens our economy, enhances our 
competitiveness, and supports the well-being of our communities. The Sierra Luna Energy Storage 
Project represents such a development, and we urge you to approve it. 
Sincerely, 
 
 
 
Danny Seiden 
President & CEO

May 13, 2025 
 
Maricopa County Planning & Zoning Commissioners 
Board of Supervisors Auditorium 
205 W Jefferson Street 
Phoenix, AZ 85003 
 
Dear Commissioners: 
I am writing to strongly support the Sierra Luna Energy Storage project. A reliable and resilient energy 
infrastructure is crucial for attracting and retaining businesses within our state. Companies across all 
sectors, particularly in technology and manufacturing, depend on a stable power supply to operate 
efficiently and expand their operations.  
A significant advantage of the Sierra Luna Energy Storage project is its anticipated role in enhancing the 
state's appeal to companies concerned with energy availability. According to the Common Sense 
Institute, Arizona's electricity demand is projected to increase by 60% over the next 30 years, 
necessitating an addition of 57 GW of new generation capacity. Arizona must take proactive measures 
to address this issue, and the Sierra Luna Energy Storage project is poised to contribute significantly to 
meeting the state's energy needs. 
Maricopa County will benefit from the project's substantial capital expenditure, which will generate 
construction jobs and increase local tax revenues. These economic advantages will have a positive ripple 
effect throughout the region, stimulating the local supply chain and improving the quality of life for 
residents of Arizona. 
The Sierra Luna Energy Storage project aims to develop innovative energy solutions, improve our energy 
infrastructure, stimulate economic growth, and enhance the state's competitiveness. Thank you for your 
consideration. Please do not hesitate to reach out with any questions.  
Sincerely, 
 
Sandra Watson 
President & CEO 
Arizona Commerce Authority

Maricopa County Planning and Zoning Commission 
301 W. Jefferson St. 
Phoenix, AZ 85003 
  
May 9, 2025 
  
Subject: Letter of Support for Sierra Luna Energy Storage Project 
Dear Arizona Corporation Commissioners, 
On behalf of the Arizona Technology Council, I am writing to express our strong support for the Sierra Luna 
Energy Storage Project. As the state’s premier trade association representing science and technology 
companies, we recognize that a reliable, modern energy infrastructure is foundational to Arizona’s continued 
economic growth and competitiveness. 
Our state is experiencing a surge in business relocations and industrial development, driven by a favorable 
economic climate and a highly skilled workforce. Arizona’s utilities have clearly identified the need for 
additional power capacity to meet this rising demand. The Sierra Luna project is a timely and necessary 
solution that addresses this challenge head-on. 
At the Council, we advocate for an “all of the above” energy strategy—excluding coal—that leverages a diverse 
mix of resources. Battery storage is a critical enabler of this strategy. It enhances grid stability, balances 
fluctuating demand, and will lead to energy savings for Arizona consumers.   
Modern battery storage systems are safe, reliable, and rigorously engineered. They incorporate advanced 
technologies and strict safety protocols to ensure dependable performance, helping to prevent service 
disruptions while reinforcing grid resilience. 
The Sierra Luna Energy Storage Project is more than just an energy infrastructure upgrade—it is an 
investment in Arizona’s future. It will strengthen our power grid, bolster our growing technology ecosystem, and 
support sustainable economic development across the state. 
We urge your approval of this important project and stand ready to support its success. 
Sincerely, 
Steve  
ARIZONA TECHNOLOGY COUNCIL & SCITECH INSTITUTE 
 
 
 
Steven G. Zylstra 
President & CEO

6751 N. Sunset Blvd. Suite 210  
 
 
 
 
 
 
 
               Tax ID: 86-0666418 
Glendale, AZ  85305                                                                                                                                          623.435.0431 
May 6, 2025 
Maricopa County Planning and Zoning Commissioners 
Subject: Letter of Support for Sierra Luna Energy Storage Project 
Dear Commissioners, 
On behalf of WESTMARC, I am writing to express our strong support for the Sierra Luna Energy 
Storage Project. WESTMARC is a coalition of 15 West Valley cities, towns, and Native 
American nations committed to enhancing the economic and social prosperity of our region. We 
believe the Sierra Luna project aligns with our mission to promote responsible growth, 
infrastructure development, and a high quality of life for our communities. 
The West Valley is experiencing significant population and economic growth, which is driving 
increased demand for reliable and sustainable energy sources. The Sierra Luna project will play 
a crucial role in meeting this demand by providing a modern, efficient, and flexible energy 
storage solution. This project will enhance grid stability, facilitate the integration of renewable 
energy resources, and ensure a reliable power supply for our growing communities. 
Investments in energy infrastructure, like the Sierra Luna project, are vital to attract and retain 
businesses, support job creation, and sustain our region's economic competitiveness. A robust 
and reliable energy grid is essential for businesses to operate efficiently and expand their 
operations in the West Valley. 
WESTMARC’s legislative agenda supports appropriate action to ensure Arizona has an 
adequate supply of gasoline, broadband, electricity, natural gas, water and other critical 
resources and the protection of critical energy infrastructure, including generation, transmission, 
and distribution assets 
We support the development of innovative energy solutions that not only meet our 
current needs but also contribute to a more sustainable future. The Sierra Luna Energy 
Storage Project represents such a solution, and we urge you to approve this project. 
Sincerely, 
 
Sintra Hoffman 
President & CEO, WESTMARC

QB\96723138.6 
 
WHEN RECORDED RETURN TO: 
Benjamin Graff, Esq.  
Quarles & Brady LLP 
One Renaissance Square 
Two North Central Avenue, Suite 600 
Phoenix, Arizona  85004 
DEVELOPMENT AGREEMENT 
THIS DEVELOPMENT AGREEMENT (the “Agreement”) is made as of the 8th day of 
July 2025, by, between and among CITY OF AVONDALE, ARIZONA, an Arizona municipal 
corporation (the “City”), and SIERRA LUNA ENERGY STORAGE LLC, a Delaware limited 
liability company (“Developer”).  City and Developer are sometimes referred to in this Agreement 
collectively as the “Parties”, or each individually as a “Party.” 
RECITALS 
A.
MARWEST ENTERPRISES, L.L.C., an Arizona limited liability company, and
CAMARUS, L.L.C., an Arizona limited liability company (collectively, “Fee Owner”) own the 
approximately 18.5 acres of real property located in unincorporated Maricopa County, Arizona, 
north of the northeast corner of south Avondale Boulevard and west Broadway Road, directly east 
and south of the jurisdictional boundary of the City of Avondale, and legally described on 
Exhibit A (the “Property”).  Developer has the right to purchase the Property pursuant to a 
separate, recorded agreement between Developer and Fee Owner. Fee Owner is executing this 
Agreement solely for purposes of acknowledging this Agreement and consenting to the recordation 
of this Agreement against the Property.  
B.
Following its acquisition of the Property, Developer intends to construct, operate
and maintain a private battery energy storage system project on the Property consisting of an 
approximately 150-megawatt/1,200-megawatt-hour standalone battery energy storage system 
(“BESS”) and related equipment, facilities and structures including a tie-line with interconnection 
to the Salt River Project (“SRP”) Rudd Substation (the “Project”).  
C.
The Project is adjacent to a strip of real property owned by the Maricopa County
(the “County”) and assigned Assessor’s Parcel Number 101-23-014 (“County Parcel”).  The 
County Parcel is situated between the Property and Avondale Boulevard.  The Project will require 
entitlements from Maricopa County (the “County”), including a rezoning of the Property from 
Rural-43 to Light Industrial (IND-2) with an Industrial Unit Plan of Development (IUPD), to be 
considered and approved by the Maricopa County Board of Supervisors, as well as a Plan of 
Development (POD), which may be approved administratively by County staff. All such 
entitlements, when approved, and following expiration of applicable appeal and referendum 
25-303C

QB\96723138.6 
 2
periods with no appeal or referendum then pending, are collectively referred to as the “County 
Entitlement Approvals”. 
D.
The Project will require approvals from the City including, rights-of way, licenses,
design, engineering, construction and other necessary approvals for the Project’s transmission 
infrastructure and access, consisting of the interconnection tie-line crossing Avondale Boulevard 
west of the Property and crossing private properties located between Avondale Boulevard and the 
Rudd Substation connecting the Project to the SRP Rudd Substation and any associated 
transmission and appurtenant facilities, to the extent located within City jurisdiction (all such 
approvals, when granted, and following expiration of applicable appeal and referendum periods 
with no appeal or referendum then pending, are collectively referred to as the “City Infrastructure 
Approvals”).   
E.
Developer previously constructed a similar BESS in the City of Avondale
northwest of the Project, called the Sierra Estrella Energy Storage facility, and the Parties 
acknowledge their previous cooperation to allow energy storage, a key component of resilient and 
reliable essential infrastructure.  The Parties acknowledge that BESSs provide backup power 
during outages, enhance grid stability, and support the integration of renewable energy, making 
them particularly valuable for hospitals, emergency services, water utilities, and public safety 
operations. 
F.
Although the Property is outside the City limits, the City, as the nearest jurisdiction
to provide emergency response services, will likely be responding to emergency events on or near 
the Project and providing services to the Project and the surrounding area.  Developer will ensure 
that the emergency response and fire protection requirements for the Project meet the City’s 
standards and needs for safely and efficiently responding to and providing emergency response 
services for the Project and the surrounding area (the “Emergency Response Requirements”), as 
further described in this Agreement.  
G.
In recognition of the significant benefits that will accrue to City (and the general
public) as a result of the Project and the voluntary financial contribution to the City, which benefits 
include (i) the improvement of public roadways, (ii) increased opportunities for commercial 
property development, and (iii) incentivizing the development of adjacent properties, City and 
Developer desire to cooperate in facilitating the Project,  as more fully set forth in this Agreement. 
H.
The Parties understand and acknowledge that this Agreement is a “Development
Agreement” within the meaning of, and is entered into pursuant to, Arizona Revised Statutes 
(“A.R.S.”) § 9-500.05. 
AGREEMENT 
Now, therefore, in consideration of the foregoing recitals and representations and the 
mutual promises contained in this Agreement, the Parties agree as follows:

QB\96723138.6 
 3
1.
PURPOSE AND TERM OF THIS AGREEMENT.
1.1 
Recitals; Rules of Construction.  The Recitals set forth in Paragraphs A
through H, inclusive, are incorporated into this Agreement by reference and form a part of this 
Agreement.  The use of the term “shall” in this Agreement means a mandatory act or obligation. 
Unless the context requires otherwise, the term “including” means “including but not limited to” 
or “including without limitation.”   
1.2 
Purpose.  The purpose of this Agreement is to facilitate the planning and 
development of the portions of the Project that will impact existing and planned infrastructure. 
This Agreement also provides for Developer’s voluntary financial contribution to the City for the 
purposes of improving south Avondale Boulevard and enhancing emergency response services at 
the Project. These efforts are of mutual interest to the City and Developer and are intended to 
improve public safety and enhance the functionality of Avondale Boulevard as a key 
transportation corridor. 
1.3 
Effective Date. The “Effective Date” of this Agreement means the date on 
which all the following have occurred: (i) this Agreement has been adopted and approved by the 
City Council of City (“City Council”), (ii) any appeal or referendum periods have expired 
pursuant to A.R.S. § 9-500.05(F), and (iii) this Agreement has been executed by duly authorized 
representatives of City, Developer, and Fee Owner. 
1.4 
Term. The Term of this Agreement shall commence on the Effective Date 
and shall remain in effect for a period of ten (10) years, unless earlier terminated as provided 
herein (the “Term”). 
1.5 
Termination.  Developer’s obligations under this Agreement shall 
terminate upon the Developer’s full payment of the Voluntary Contribution (as defined below) to 
City. Additionally, Developer may terminate the Agreement at any time prior to obtaining 
Governmental Approvals (also defined below) by providing fifteen (15) days’ written Notice to 
City.  For avoidance of doubt, if Developer terminates this Agreement pursuant to the 
immediately preceding sentence, Developer shall have no obligation to pay the Voluntary 
Contribution. Further, this Agreement shall automatically terminate if Developer does not 
purchase the Property from Fee Owner by December 31, 2028. Developer, the City, and Fee 
Owner agree to cooperate in good faith to promptly record a termination and release of this 
Agreement following any termination of this Agreement as provided herein. 
2.
SCOPE AND REGULATION OF DEVELOPMENT.
2.1 
Project Scope. The Project consists of the development, construction,
operation, and maintenance of a standalone approximately 150-megawatt/1,200-megawatt-hour 
private battery energy storage system facility and related infrastructure on the Property, including 
the interconnection tie-line and associated transmission facilities connecting the Project due 
westward to the SRP Rudd Substation.  Development of the Project shall proceed in accordance 
with the terms of this Agreement, applicable County Entitlement Approvals, and City 
Infrastructure Approvals.

QB\96723138.6 
 
 
 
 
 
4
2.2 
City Infrastructure Approvals and Design Compliance. The City has the 
authority to grant all City Infrastructure Approvals for the Project, which are limited to those 
components of the Project located within City jurisdiction, including but not limited to the 
transmission corridor and related improvements within the south Avondale Boulevard right-of-
way. Developer shall design and construct such improvements in accordance with all applicable 
City codes, standards, and conditions of approval.  
2.3 
Governing Code and City Cooperation. For purposes of the City 
Infrastructure Approvals, the applicable City codes and standards shall be those in effect as of the 
Effective Date of this Agreement and shall continue to apply through final inspection and 
approval of the Project infrastructure. City shall cooperate reasonably in processing the City 
Infrastructure Approvals required for the development and construction of the Project. 
2.4 
Project Review and Coordination. The City designates the City Engineer 
as the primary point of contact to coordinate the review and inspection of the City Infrastructure 
Approvals.  The City shall make reasonable efforts to provide consistency in plan review and 
field inspections by assigning the same or similar personnel throughout the development period.  
2.5 
Fees. Developer shall pay all standard and applicable City permitting, 
inspection, and development fees required by the Avondale City Code in effect at the time of each 
respective application submittal. Nothing in this Agreement shall waive or reduce the obligation 
of Developer to pay such fees, unless otherwise expressly provided. 
3. 
DEVELOPER’S 
VOLUNTARY 
CONTRIBUTION 
TO 
CITY 
INFRASTRUCTURE. 
3.1 
Developer’s Voluntary Contribution of Funds. Developer agrees to make 
the following voluntary financial contribution to the City in accordance with this Article 3 for the 
purposes of assisting the community and supporting the City’s public initiative of improving and 
beautifying Avondale Boulevard and enhancing emergency response initiatives in connection 
with the Project (“Voluntary Contribution”). Developer confirms that this contribution is not, 
and shall not be construed as an exaction, impact fee, or any form of mandatory payment required 
by City, its ordinances, policies or regulations in connection with the Project or any aspect thereof. 
Developer hereby waives and forever releases, any right or claim that may arise under ARIZ. REV. 
STAT. § 9-500.13 (Compliance With Court Decisions), including any claim that the City coerced 
or required payment of the Voluntary Contribution in exchange for the City Infrastructure 
Approvals, or any other item of value or exercise of City discretion in favor of the Developer or 
the Project, together with any claim alleging that the City engaged in any unlawful or 
unconstitutional taking of property rights.  
3.2 
Voluntary Contribution Amount. Subject to the further terms of this 
Agreement, Developer shall pay to the City a total amount of Three Million Two Hundred Fifty 
Thousand Dollars ($3,250,000) (the “Voluntary Contribution Amount”). The Voluntary 
Contribution Amount may also be referred to herein as the “Funds” when describing the City’s 
use of the Voluntary Contribution.

QB\96723138.6 
 
 
 
 
 
5
3.3 
Payment Contingency.  Developer’s obligation to make the Voluntary 
Contribution described in Section 3.2 shall be contingent upon the satisfaction of all of the 
following conditions: (i) the Project receiving all County Entitlement Approvals, (ii) the Project 
receiving all City Infrastructure Approvals, and (iii) Developer applying for and receiving from 
Maricopa County a building permit for Project infrastructure on the Property (collectively, the 
“Governmental Approvals”). For avoidance of doubt, this Agreement does not impose on 
Developer any obligation to apply for the Governmental Approvals or to proceed with 
construction of the Project.  This Agreement imposes on Developer the obligation to pay the 
Voluntary Contribution if and when Developer elects to obtain, and receives, all of the 
Governmental Approvals. The receipt of the Voluntary Contribution by the City does not create 
an obligation on the part of the City to approve or expedite any of the City Infrastructure 
Approvals, nor does it obligate the City to provide any specific level of support, endorsement or 
non-opposition to the Project beyond that which is generally afforded to development projects 
located in the County and adjacent to the City. 
3.4 
Payment Timing. Developer shall pay the Voluntary Contribution Amount 
in one lump sum to the City within five (5) business days after the later of (i) issuance by the 
County of a building permit for Project infrastructure on the Property and (ii) the Project receiving 
the City Infrastructure Approvals.  
3.5 
Acceptable Methods of Payment. All payments due under this Article 3 
shall be made by wire transfer, certified check, or such other method as may be reasonably 
approved in writing by the City. Payments shall be made in immediately available funds to an 
account or address designated in writing by the City. 
4. 
PURPOSE 
AND 
USE 
OF 
FUNDS; 
EMERGENCY 
RESPONSE 
COVENANTS. 
4.1 
Use of Funds. City shall use the Funds for the following public purposes: 
(a) 
Improvements along south Avondale Boulevard, including but not 
limited to paving, signage, water delivery, civil improvements, irrigation, stormwater design, 
landscaping, buffering, and electrical utility infrastructure; and enhancing local emergency 
response capabilities, including equipment, training, and operational support, as determined 
appropriate by the Avondale Fire and Medical Department; and  
(b) 
Following receipt of the Voluntary Contribution, the City may 
allocate and expend the Funds at its sole discretion to further the purposes set forth in this 
Section 4.1, provided such use remains consistent with the terms of this Agreement and applicable 
laws.  
The City considered the following cost estimates, provided by independent consultants who were 
engaged by the City and the Developer, to identify the following uses of the Funds: 
 
 
Paving  
 
 
  $525,000 
 
 
Signage 
 
 
      $8,000

QB\96723138.6 
 
 
 
 
 
6
 
 
Irrigation 
 
 
$2,302,000 
 
 
Electrical Utilities 
 
   $200,000 
 
 
Avondale Fire and Medical    $215,000 
4.2 
No Developer Liability.  Final allocation, budgeting and expenditure of all 
Funds shall be in accordance with the City’s adopted procedures. Developer shall have no 
obligation, responsibility, or liability for any actions taken by the City in connection with the use, 
management, or allocation of the Funds, including whether the Funds are used for the intended 
public purposes. Payment of the Voluntary Contribution shall constitute full satisfaction of 
Developer’s obligations under this Agreement. 
4.3 
City Emergency Response Requirements.  Developer will allow the City 
Fire Chief or Fire Marshal to perform a courtesy review of the County Plan of Development, prior 
to the County’s final approval of the Plan of Development, to confirm compliance with the 
following Emergency Response Requirements for the Project: 
(a) 
Developer shall provide two (2) access driveways to the Property 
from South 113th Avenue. 
(b) 
The spacing of battery units on the Property shall comply with 
NFPA 855 and OSHA 1926. 
(c) 
Developer shall include two (2) 24,000-gallon water tanks on 
Property, with the ability to connect to the water tanks from outside of the perimeter wall. 
(d) 
Developer shall retain a third-party services provider to refill water 
tanks, as needed to support response efforts. 
(e) 
Developer shall coordinate with the City of Avondale Fire and 
Medical Department and Rural Metro to provide onsite training, at Developer’s cost. 
Developer will request County to include the above five (5) Emergency Response Requirements 
as Conditions of Approval attached to County Rezoning Case No. Z25007 and the corresponding 
Ordinance. City acknowledges that (i) County is the sole regulatory authority with zoning and land 
use authority over the Property, and (ii) the above covenants are private covenants from Developer 
to City, are enforceable by City as limited by the scope of each of the five (5) covenants, and do 
not establish any regulatory authority of the City with respect to the Property, which is located 
within the jurisdiction of the County.  Should the County impose Conditions of Approval that 
deviate or otherwise conflict with the five (5) Emergency Response Requirements, Developer and 
City shall work in good faith to identify a solution that meets the intent of each item in conflict. 
4.4 
Annexation.  Developer and City agree after Developer has received a 
certificate of occupancy from the County, each, in its sole and absolute discretion, may consider 
entering into discussions regarding the  future annexation of the Property into the City, but without 
any obligation to enter into such discussions or to annex the Property into the City.

QB\96723138.6 
 
 
 
 
 
7
5. 
REPRESENTATIONS BY THE PARTIES.  Each Party represents and 
warrants to the other Party that: 
5.1 
The representing Party has the full right, power, and authorization to enter 
into and perform this Agreement. 
5.2 
All consents and approvals necessary for the execution, delivery and 
performance of this Agreement by the representing Party have been obtained. 
5.3 
The representing Party shall execute, and acknowledge when appropriate, 
all documents and instruments, and shall take all actions, in each case necessary to implement, 
evidence and enforce this Agreement. 
5.4 
The representing Party has been assisted by counsel of its own choosing in 
connection with the preparation and execution of this Agreement. 
6. 
DEFAULT AND ENFORCEMENT. 
6.1 
Events of Default.  “Default” or an “Event of Default” by Developer or 
City under this Agreement shall mean one or more of the following:  
(a) 
Any representation or warranty made in this Agreement by the Party 
was materially inaccurate when made or shall prove to be materially inaccurate during the Term; 
and  
(b) 
Such Party fails to observe or perform any other covenant, 
obligation or agreement required of it under this Agreement.  
6.2 
Grace Periods; Notice and Cure.  Upon the occurrence of an Event of 
Default by any Party, such Party shall, upon written Notice from any other Party, proceed 
immediately to cure or remedy such Default and, in any event, such Default shall be cured within 
thirty (30) days after receipt of such Notice; or, if such Default is of a nature that is not capable 
of being cured within thirty (30) days, the cure or remedy shall be commenced within such period 
and diligently pursued to completion, but in no event exceeding ninety (90) days in total.   
6.3 
Remedies for Default.  In the Event of Default under any provision of this 
Agreement where the same is not cured within the applicable time period set forth above, the non-
defaulting Party shall have all remedies available to it at law or in equity. Except as otherwise 
expressly stated in this Agreement, the rights and remedies of the Parties are cumulative, and the 
exercise by any Party of one or more of such rights or remedies will not preclude the exercise by 
it, at the same time or different times, of any other rights or remedies for the same default or any 
other default by such defaulting party. 
6.4 
Venue. Any legal actions instituted pursuant to this Agreement must be 
filed in the county of Maricopa, State of Arizona, or in the Federal District Court in the District 
of Arizona.

QB\96723138.6 
 
 
 
 
 
8
6.5 
Waiver. Except as otherwise stated in this Agreement, failure by any Party 
in asserting any of its rights or remedies as to any Default, will not operate as a waiver of any 
Default, or of any such rights or remedies, or deprive any such Party of its right to institute and 
maintain any actions or proceedings which it may deem necessary to protect, assert or enforce 
any such rights or remedies. 
6.6 
No Liability.  No member of the City Council, nor any officer, agent, 
attorney, or employee of the City, shall be personally liable for any breach or default under this 
Agreement. Similarly, Developer’s obligations under this Agreement are limited to its assets. The 
personal assets of its members, managers, officers, directors, partners, or shareholders shall not 
be subject to any claims arising from this Agreement. 
7. 
MISCELLANEOUS PROVISIONS.  
7.1 
Assignment. Developer shall have the right to assign all or a portion of its 
interest under this Agreement to an owner of all or any portion of the Property only with the prior 
consent of City, which consent will not be unreasonably withheld, conditioned or delayed; 
provided that City’s consent shall not be required for an assignment in whole or in part to a 
Developer Affiliate.  City’s rights and obligations under this Agreement shall be non-assignable 
and non-transferable, without the prior express written consent of Developer, which consent will 
not be unreasonably withheld, conditioned or delayed.  For purposes of this Agreement, an 
“Affiliate,” means any person or entity directly or indirectly controlling, controlled by, or under 
common control with Developer.  Without limiting the foregoing, the Parties expressly 
acknowledge that the rights and obligations of Developer are personal to Developer, for 
Developer’s proposed development of the Property, and Fee Owner will have no obligation or 
liability to perform the obligations of Developer under this Agreement.   
7.2 
Limited Severability.  City and Developer each believes that the execution, 
delivery, and performance of this Agreement are in compliance with all applicable laws.  
However, in the unlikely event that any provision of this Agreement is declared void or 
unenforceable (or is construed as requiring City to do any act in violation of any applicable laws), 
such provision shall be deemed severed from this Agreement and this Agreement shall otherwise 
remain in full force and effect; provided that this Agreement shall retroactively be deemed 
reformed to the extent reasonably possible in such a manner so that the reformed agreement (and 
any related agreements effective as of the same date) provide essentially the same rights and 
benefits (economic and otherwise) to the Parties as if such severance and reformation were not 
required.   
7.3 
Notices.  
(a) 
All “Notices”, demands or other writings in this Agreement 
provided to be given, made or sent by any Party hereto to the other Party must be made in writing 
and will be deemed to have been fully given, made or sent (i) on the day personally delivered or 
served; or (ii) on the day delivered is sent by recognized overnight courier service (e.g., FedEx or 
UPS) for next business day delivery; or (iii) three (3) business days after deposit in the United 
States mail postage prepaid and sent by registered or certified mail, and in each case addressed as 
follows:

QB\96723138.6 
 
 
 
 
 
9
 
If to City:  
 
 
City of Avondale 
Attn: Ron Corbin, City Manager 
11465 W. Civic Center Drive  
Avondale, Arizona  85323 
Email: rcorbin@avondaleaz.gov  
 
With a required copy to:   
City of Avondale 
Attn: Nicholle Harris, City Attorney 
11465 W. Civic Center Drive 
Avondale, Arizona  85323 
Email: nharris@avondaleaz.gov  
 
If to Developer:  
 
Sierra Luna Energy Storage LLC 
 
 
c/o Plus Power LLC 
 
 
Attn: General Counsel 
 
 
1780 Hughes Landing Blvd, Suite 675 
 
 
The Woodlands, TX 77380 
 
 
Email: legal@pluspower.com  
 
             With a required copy to:   
Quarles & Brady LLP 
Attn: Benjamin Graff 
One Renaissance Square 
Two North Central Avenue, Suite 600 
Phoenix, Arizona  85004  
Email: benjamin.graff@quarles.com  
 
 
 
Each Party may by notice in writing change its address for the purpose of this Agreement, which 
address shall thereafter be used in place of the former address.  
 
7.4 
Entire Agreement.  Except as expressly provided in this Agreement, this 
Agreement constitutes the entire agreement between the Parties with respect to the subject matters 
hereof and supersedes any prior agreement. 
7.5 
Further Assurances.  Each Party agrees to perform such other and further 
acts and to execute and deliver such additional agreements, documents, affidavits, certifications, 
acknowledgments and instruments as the other Party may reasonably require to consummate, 
evidence, confirm or carry out the matters contemplated by this Agreement or confirm the status 
of (a) this Agreement as in full force and effect and (b) the performance of the obligations 
hereunder at any time during its Term.  
7.6 
Recordation.  Within ten (10) days after this Agreement has been approved 
by City and executed by the Parties, City shall cause this Agreement to be recorded in the Official 
Records of Maricopa County. 
7.7 
Amendment.  All amendments to this Agreement must be in writing and 
signed by the appropriate authorities of the Parties hereto and recorded in the Official Records of 
Maricopa County.

QB\96723138.6 
 
  
 
 
10
 
[Signatures appear on following pages]

QB\96723138.6 
 
SIGNATURE PAGE TO DEVELOPMENT AGREEMENT 
DEVELOPER 
SIERRA LUNA ENERGY STORAGE LLC,  a 
Delaware limited liability company,  
By:  ______________________________ 
Its:  ______________________________ 
STATE OF ARIZONA 
) 
) ss. 
COUNTY OF __________ 
) 
The foregoing instrument was acknowledged before me this _____ day of ________, 2025, 
by _________________________________, the ___________________ of SIERRA LUNA 
ENERGY STORAGE LLC, a Delaware limited liability company, who acknowledged that he/she 
signed the foregoing instrument on behalf of Developer.  
____________________________________ 
Notary Public  
My commission expires:  
____________________

QB\96723138.6 
 
 
 
 
ACKNOWLEDGMENT OF FEE OWNER 
 
The undersigned has executed the foregoing Agreement for the purposes of expressly consenting 
to the recordation of this Agreement against the interest of Fee Owner in and to the Property and 
has authorized and approved the execution and delivery of the foregoing Development Agreement. 
 
 
MARWEST ENTERPRISES, L.L.C. , an Arizona 
limited liability company 
 
 
By:  
 
Name:  
Title:    
 
 
 
STATE OF ARIZONA 
) 
 
) 
County of Maricopa 
) 
The foregoing instrument was acknowledged before me this _____ day of _____________, 
2025, by ___________________, the _____________________ of MARWEST ENTERPRISES, 
L.L.C., an Arizona limited liability company, on behalf of the company.   
 
 
 
Notary Public 
 
My commission expires: _______________________ 
[Seal]

QB\96723138.6 
 
 
 
 
 
ACKNOWLEDGMENT OF FEE OWNER 
 
The undersigned has executed the foregoing Agreement for the purposes of expressly consenting 
to the recordation of this Agreement against the interest of Fee Owner in and to the Property and 
has authorized and approved the execution and delivery of the foregoing Development Agreement. 
 
 
CAMARUS, L.L.C. , an Arizona limited liability 
company 
 
 
By:  
 
Name:  
Title:    
 
 
 
STATE OF ARIZONA 
) 
 
) 
County of Maricopa 
) 
The foregoing instrument was acknowledged before me this _____ day of _____________, 
2025, by _______________________, the ________________ of CAMARUS, L.L.C., an Arizona 
limited liability company, on behalf of the company.   
 
 
 
Notary Public 
 
My commission expires: _______________________ 
[Seal]

QB\96723138.6 
 
 
 
 
 
List of Exhibits 
 
Exhibit A: 
Legal Description of Property

QB\96723138.6 
 
 
 
 
 
Exhibit A 
Legal Description of Property 
 
PARCEL NO. 1:  
Lot 4 of the Southwest quarter of the Southwest quarter of Section 19, Township 1 North, Range 
1 East of the Gila and Salt River Base and Meridian, Maricopa County, Arizona; 
 
EXCEPT the South half thereof; 
 
EXCEPT the West 99 feet therof; and 
 
EXCEPT the South 324 feet of the West 200 feet thereof. 
 
PARCEL NO. 2:  
The South 324 feet of the West 200 feet of the following described property:  
 
Lot 4 of the Southwest quarter of the Southwest quarter of Section 19, Township 1 North, Range 
1 East of the Gila and Salt River Base and Meridian, Maricopa County, Arizona; 
 
EXCEPT the South half thereof;  
 
EXCEPT the West 99 feet thereof. 
 
PARCEL NO. 3: 
That part of Lot 4, Section 19, Township 1 North, Range 1 East of the Gila and Salt River Base 
and Meridian, Maricopa County, Arizona, described as follows: 
 
BEGINNING at the Southwest corner of said Section 19; 
 
THENCE North 88 degrees 41 minutes 10 seconds East 99.00 feet; 
 
THENCE North 0 degrees 28 minutes 10 seconds West 505.63 feet to the True Point of Beginning, 
said point also being the Northwest corner of said property described in instrument recorded in 
Docket 10400, page 1304, records of Maricopa County, Arizona; 
 
THENCE North 0 degrees 20 minutes 10 seconds West 155.21 feet; 
 
THENCE North 88 degrees 41 minutes 10 seconds East 287.42 feet; 
 
THENCE South 0 degrees 28 minutes 10 seconds East 155.21 feet to the Northeast corner of 
property described in instrument recorded in said Docket 10400, page 1304, records of Maricopa 
County, Arizona;

QB\96723138.6 
 
 
 
 
 
 
THENCE along the North line of property described in instrument recorded in said Docket 10400, 
page 1340, records of Maricopa County, Arizona, South 88 degrees 41 minutes 10 seconds West 
287.42 feet to the TRUE POINT OF BEGINNING. 
 
PARCEL NO. 4: 
An easement for ingress, egress and utilities purposes as created by instrument recorded in 
Docket 10400, page 1291, records of Maricopa County, Arizona, over the East 20 feet of the 
following described property: 
 
BEGINNING at the Southwest corner of Section 19, Township 1 North, Range 1 East of the Gila 
and Salt River Base and Meridian, Maricopa County, Arizona; 
 
THENCE North 88 degrees 41 minutes 10 seconds East 99.00 feet; 
 
THENCE North 0 degrees 28 minutes 10 seconds West 40 feet to the True Point of Beginning; 
 
THENCE North 0 degrees 28 minutes 10 seconds West 465.63 feet; 
 
THENCE North 88 degrees 41 minutes 10 seconds East 287.42 feet; 
 
THENCE South 0 degrees 28 minutes 10 seconds East 465.63 feet; 
 
THENCE South 88 degrees 41 minutes 10 seconds West 287.42 feet to the TRUE POINT OF 
BEGINNING.