Narrative

Ellsworth II - Battery Energy Storage System (BESS)
+/- 20.32 acres
Mesa, Arizona
Rezoning Project Narrative
Submitted by:
Pew & Lake, PLC
1744 South Val Vista Drive, Suite 217
Mesa, AZ 85204
480-461-4670
On behalf of:
Submitted to:
The City of Mesa
Planning & Zoning Division
February 9, 2026

Table of Contents
1. Introduction .............................................................................................................. 3
2. About NextEra Energy Resources, LLC ................................................................... 3
3. Existing Land Use Designations, Zoning and Uses.................................................. 4
4. Surrounding Context ................................................................................................ 5
5. Request .................................................................................................................... 6
6. Project Overview ...................................................................................................... 6
Nameplate Capacity .................................................................................................... 7
Phasing and Augmentation .......................................................................................... 8
7. Compatibility with Surrounding Uses ........................................................................ 8
8. General Plan Analysis .............................................................................................. 9
9. Mesa Gateway Strategic Development Plan (MGSDP) ......................................... 10
10. Airfield Overflight Area 3 ..................................................................................... 11
11. Zoning Analysis .................................................................................................. 12
Compliance with Light Industrial (LI) Development Standards .................................. 12
Compliance with BESS Ordinance ............................................................................ 12
12. Conclusion .......................................................................................................... 15
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1. Introduction
Pew & Lake, PLC (the “Applicant”) on behalf of Ellsworth Energy Center, LLC, a subsidiary
of NextEra Energy Resources, LLC (“NextEra”), is pleased to submit this project narrative
to the City of Mesa (the “City”) in support of a rezoning request to allow for the
development of a Battery Energy Storage System (“BESS”) facility, (the “Project”). The
Project is proposed to be developed on approximately 20.3 acres of property located on
the north side of Starfire Avenue, east of Ellsworth Road (the “Property”). The Property is
shown below and is a portion of Maricopa County Assessor parcel number 304-31-0149A.
The approximate boundary of the entire parcel is shown below, outlined in red.
2. About NextEra Energy Resources, LLC
NextEra Energy Resources, LLC (together with its affiliated entities, "NextEra Energy
Resources") is one of the nation’s top wholesale generators of electric power, with
approximately 33,000 megawatts of net generating capacity from all forms of energy,
including nuclear, natural gas, renewables and battery storage, in over 40 states and
Canada. NextEra Energy Resources offers a wide range of energy solutions to help
businesses and customers across the country meet their emissions reduction goals.
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With the development of the Property within the City of Mesa, NextEra will develop an
estimated 190 MW/ 8-hr BESS facility. The Project’s major components include BESS
containers, inverter stations, and a network of circuits that will route power to an adjacent
Project substation that is owned and operated by Salt River Project. Increasing the
capability of the power grid is vitally important in Arizona, and especially in this part of
the City, where high value technology users with extraordinary energy needs have
developed in recent years.
3. Existing Land Use Designations, Zoning and Uses
As shown in the graphics below, the Property (outlined in red) is surrounded on all sides
by land with a similar General Plan 2050 placetype: Regional Employment Center with an
Evolve Growth Strategy. There is a property on the south side of Starfire Avenue that is
currently the subject of a minor General Plan amendment request to change the placetype
designation from Urban Residential, to Local Employment Center. When approved that
request will allow for industrial and commercial uses on that property and remove any
residential adjacencies from the subject Property.
City of Mesa General Plan 2050 Land Use Map
The Property is zoned Light Industrial (LI), with a Planned Area Development (PAD)
Overlay. The PAD applicable to the Property was approved in February of 2022 in
Ordinance No. 5677 and is called the Warner Gateway 202 PAD.
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City of Mesa Zoning Map
The Property is currently vacant. There is a large drainage easement that runs along the
southern boundary of the subject property that diverts water to another drainage
easement that is adjacent to this property, along the western boundary.
4. Surrounding Context
As shown in the graphic on the next page, the Property is just east of the 35-acre SRP
Scott substation. It is adjacent to several existing industrial buildings, and just north of
the Scott substation is the 16-acre Edged Data Center property that was approved in 2023
in case ZON23-0549 and contains a 127,924 square foot data center. North of Warner
Road, there is a 158-acre property owned by Novva Data Centers, with an approved 300
MW data center campus. The Novva facility is proposed to have five data halls, an office
building and warehouse with a 1.3 million square footprint. Each of these users will
dramatically increase the demand for available and reliable energy in this part of the City.
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5. Request
The specific request to the City of Mesa is for:
A rezone of approximately 20.32 acres of property from Light Industrial
with a Planned Area development (LI/PAD), to Light Industrial, without a
Planned Area Development.
Approval of this request will allow for the development of a BESS facility in compliance
with the Light Industrial zoning requirements and development standards contained in
Section 11-8-3 of the Mesa Zoning Ordinance (“MZO”), as well as the development
requirements and standards contained in the BESS Ordinance, Section 11-31-37 of the
Mesa Zoning Ordinance, adopted by the City on January 12, 2026 through Ordinance No.
5976.
6. Project Overview
As noted previously, NextEra will develop a utility scale BESS facility on the Property. As
shown on the Site Plan provided in the application materials, most of the property will be
devoted to the installation of BESS units and ancillary equipment. Shown on the next page
is a graphic representation of what the BESS units will look like on the Property:
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The BESS units will be located on the Property to capture excess energy that is provided
by the adjacent SRP Scott substation. Simply put, the BESS units will allow power delivered
to the electrical grid to be temporarily stored and discharged later. This storage of energy
and release will allow SRP to provide for the consistent delivery of energy to the power
grid.
In addition to the BESS units, the Property will contain interior drive aisles and perimeter
improvements that will secure the property while providing an aesthetically pleasing
appearance.
Ellsworth II is one of two parcels in this immediate area that are collectively known by Salt
River Project and NextEra as the Ellsworth Energy Center. Ellsworth I, the other portion of
the Project, is across the street, on the south side of Starfire Avenue. Due to differing
property owners and underlying entitlements, the development of these two parcels is
being pursued separately but will be developed simultaneously and combine to form one,
350 MW Battery Energy Storage Facility. SRP is the utility in final contract negotiations
with Ellsworth Energy Center, LLC to provide storage capacity in this vicinity.
Nameplate Capacity
The nameplate capacity for Ellsworth II is approximately 190 MW. When combined with
Ellsworth I, the total nameplate capacity for the Ellsworth Energy Center is approximately
350 MW.
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Phasing and Augmentation
The project will be constructed in a single phase, to achieve its full nameplate capacity at
the commencement of operations. Battery augmentation will be required over the life of
the project to continue meeting the full nameplate capacity throughout the project’s
operational term. This augmentation does not represent an increase in approved
capacity, it merely consists of the periodic replacement or addition of battery modules to
offset normal performance degradation over time.
NextEra acknowledges that if a planned augmentation will exceed the nameplate capacity
established with the approval of this rezoning request, approval of the augmentation by
the Mesa City Council will be required, per Section 11-31-37-G-2.ii, of the Mesa Zoning
Ordinance.
7. Compatibility with Surrounding Uses
The uses described in Regional Context section above describe the general context for
this rezoning application. More specifically, the uses immediately adjacent to this
property are shown below and demonstrate that the proposed BESS facility is compatible
with the uses surrounding this property. The SRP substation is west of the Property, across
a large drainage easement that serves the Warner Gateway 202 industrial development.
The remaining three sides of the Property, are surrounded by industrial uses. While the
Regional Context graphic shows the property at the southwest corner of Ellsworth and
Road and Starfire Avenue as currently zoned for residential uses, an application for the
rezoning of that property to Light Industrial and Limited Commercial will complete the
pattern of industrial development along the south side of Starfire, and will further
demonstrate the compatibility of this use to the immediately adjacent properties.
Direction Zoning Existing Use
North Light Industria (PAD)l Industrial Buildings
South Light Industrial (PAD) Industrial Buildings
East Light Industrial (PAD) Industrial Buildings
West Light Industrial SRP Scott Substation
Project Site Light Industrial (PAD) Vacant
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8. General Plan Analysis
As noted previously, the Mesa 2050 General Plan placetype for this site is Regional
Employment Center, with an Evolve growth strategy. Regional Employment Centers are
typically areas that accommodate large employers such as hospitals and medical centers,
airports, universities, corporate headquarters, high-tech companies, and research parks.
However, the placetype designation also allows for smaller business and medical offices,
light industrial uses, and other employment-based activities that are part of a cohesive
development. Regional Employment Centers typically have excellent access to major
arterial roadways and freeways and should incorporate high-quality design. Vacant land
in the Regional Employment Center placetype is intended to support new development
the brings new investment to the City of Mesa and is also encouraged to develop with
land uses that align with City priorities.
The proposed BESS facility, while not a large employer, is a smaller, industrial use. This
project and its location have been chosen in consultation with the City and Salt River
Project, to act as a supporting player for the large number of developed and approved
industrial uses in this part of the City, each of which have large electrical needs.
Additionally, with the rapid growth of the Eastmark and Cadence residential communities,
and others that are under development, the residential need for power in this area
continues to increase.
By using this vacant property to bolster SRP’s ability to provide consistent and reliable
power to residential and industrial energy consumers, the use of this property aligns with
the City’s priority outlined in Chapter 4: The Economy in the General Plan, to create a
“resilient and sustainable City”. As discussed further in Chapter 4, the City’s pursuit of
resilience should respond to both local conditions, and a larger regional context. Most
importantly, the pursuit of sustainability should align with emerging national trends and
guidelines. As this important part of the City had developed into a major player in
industrial development, the critical need to provide power to this part of the City cannot
be understated. In fact, SRP has estimated that it needs to double its load capacity in the
next 10 years, to meet the ever-increasing demand for energy.
One of the strategies promoted in Chapter 4 is the promotion of practices that foster
resilient (energy) systems to reduce hazard risks. Such risks include brownouts caused by
a utility company’s inability to provide consistent power to all users at once. Allowing the
storage of energy in this facility, at this location is precisely the type of practice envisioned
in the General Plan.
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9. Mesa Gateway Strategic Development Plan (MGSDP)
The Project also lies within the boundaries of the Mesa Gateway Strategic Plan area. This
plan, adopted by the City of Mesa in 2008, establishes the vision for the development of
properties in proximity to Mesa Gateway Airport and within its overflight areas. Though
the plan was adopted prior to the explosion of AI and data centers on the cultural and
economic scene, there are facets of the plan that are applicable to this development, and
support approval of this project in the MGSDP area.
The MGSDP encourages developments that will promote the stability of the planning area.
The plan evaluates and promotes land uses that: 1) are economically viable, 2) are
responsive to the context of the area and specific location, 3) use resources efficiently and
are planned with a careful approach and implementation.
The Ellsworth I BESS facility is consistent with each of these elements in the following
ways:
Economically Viability: NextEra is the entity in negotiations to be contracted by
SRP to purchase the energy stored at Ellsworth Energy Center. SRP has estimated
that their energy demand in this area will double in the next ten years, and the
storage of energy is vital to ensure that every megawatt of energy that is produced
can be transmitted to residential, commercial and industrial users. Unlike many
development projects that are speculative, this project already has a dedicated
customer for the energy stored at this location.
Additionally, by enabling SRP to provide consistent and reliable energy in the Mesa
Gateway Area, the marketability of vacant properties in the area increases, and
becomes even more enticing for employers who want to locate in this important
part of the City.
Responsiveness to context and location: This location has been carefully chosen
by NextEra for a BESS facility for its proximity to the SRP Scott substation, and the
large number of existing and planned uses that have created an increase in energy
demand. As previously discussed in this narrative, as energy demand in this part
of the City increases, so does the need for a consistent and reliable energy grid.
Efficient use of resources: As an unmanned facility, a BESS facility has no on-site
employees and requires water only for perimeter landscaping, which has been
designed using low water use plants and trees. Unlike residential or large industrial
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uses, this Property can be used productively, without creating a drain on any
natural resources.
Energy as a natural resource is discussed at length in the MGSDP. In addition to
encouraging the exploration of alternative energy sources, the plan also discusses
the importance of alternative energy technologies to help reduce the cost of
energy, and to decrease the cost of energy transmission. The plan specifically
mentions on-site energy storage as a technology to be considered. With the
selection of this property for a BESS facility, Ellsworth Energy Center has capitalized
on its proximity to 230KV powerlines and the SRP Scott substation, which will assist
SRP in providing energy to its customers in a more efficient manner.
Approach and implementation: The proposed BESS facility at this location
promotes the City’s vision to create sustainability by understanding and addressing
the needs created by climate change. Traditional developments often include
measures like green building design, alternative materials, minimal pavement and
increased tree canopies to minimize the heat island effect. However, these
measures don’t fully address the need to precisely deliver existing energy to users
where and when it is most needed. The recent years have seen historically high
summer heat, with the energy grid strained to near its capacity. The need to extend
the capacity of the grid has never been more important, and this proposed BESS
facility will allow SRP to store energy that is created when it’s not needed, so that
it can provide it when it is most needed. This organized approach to energy
delivery minimizes the impact of climate change on the energy grid and allows the
City of Mesa to play a role in the reliable delivery of energy to its citizens.
10. Airfield Overflight Area 3
Finally, all development proposals in the Mesa Gateway area need to be compatible with
the airport operations. The Property lies within Airfield Overflight Area 3, the least
restrictive of the overflight areas. When examining land uses proposed for an Airport
Overflight Area, the FAA examines the operational detail of the proposed use, and studies
its proposed impact on the air quality near the airport and also evaluates the height of
any proposed structures to ensure there will be no conflict with airport operations. The
proposed BESS facility is an unmanned, non-residential use, with structures that will not
exceed the height allowed in the underlying LI zoning district. The passive use of the
property will not generate a change in air quality, nor will it generate glare, smoke or heat,
making it compatible with the airport, and the MGSDP area.
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11. Zoning Analysis
Compliance with Light Industrial (LI) Development Standards
The project has been designed to comply with all the lot and density development
standards established in Section 11-7-3 of the Mesa Zoning Ordinance, as shown below:
Light Industrial Lot and Density Development Standards
Development Standard Required Provided
Lot Area 1 acre 20.32 acres
Lot Width 100-feet 933-feet
Lot Depth 100-feet 1,048-feet
Maximum Lot coverage 90% <90%
Maximum Building Height 40-feet N/A
Setbacks:
Front (local street) 20-feet 20-feet
Side 0-feet Per BESS ordinance
Rear 0-feet 0-feet
Compliance with BESS Ordinance
The project has been designed specifically to comply with the BESS Ordinance
requirements outlined in Section 11-31-7 of the Mesa Zoning Ordinance. This compliance
includes meeting requirements for: application materials, underlying zoning district
development standards, separation requirements, spacing, drive aisle design,
landscaping, facility screening and substation screening
Bess Ordinance Requirements
Required Provided
11-31-37.B.1.a Greater than 5MW 190 MW
Principal Uses
11-31-37.E Project Narrative Provided in Application
Application materials
Requirements
Operational Plan Provided in Application
materials
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Good Neighbor Policy Provided in Application
materials
Initial Sound Study Provided in Application
materials
Citizen Participation Plan Provided in Application
materials
11-31-37.F.1 Must meet all development See discussion above
Development standards in the LI Zoning District
Standards
11-31-37.F.2 A minimum distance of 1,000 feet to +/- 1,347 feet
Separation the nearest property line of the (to Eastmark
Requirements nearest residential zoning district. Development Unit Phase 3)
A minimum distance of 400 feet to +/- 2,747 feet- Church
the nearest property line of the +/- 2,423 feet- Park
nearest church, park or school +/- 3,293 feet- school
A minimum distance of 150 feet from Will comply
the nearest point of the BESS facility
site screening wall to the nearest
wall, post or column of the nearest
commercial or industrial building.
11-31-37. F.3 Shall comply with all requirements of Will comply
BESS spacing Title 7 of the Mesa City Code
regarding setbacks and clear zones
11-31-37.F.4 Paved in accordance with 11-32-2.C Will comply
Fire access and of the Mesa Zoning Ordinance
Drive Aisles
Fire Access and Drive Aisles must Will comply
comply with all requirements of Title
7- Fire Regulations of the Mesa City
Code
11-31-37.F.5 Shall meet requirements in Section Will comply
Portable 11-30-16
Storage
Containers
11-31-37.F.6
Site Screening
BESS Facility
Height One-foot above the tallest piece of Will comply
equipment
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Wall Materials Opaque; Tinted, textured blocks, Will comply
brick, stone or ornamental metal
Wall Articulation Articulated every 40 feet using a Will comply
column or landscape pocket
Decorative Cap All columns shall have a decorative Will comply
cap
11-31-37.F.7 Will comply
Substation
Screening
Height Fully screened to a height of one- Will comply
foot taller than the tallest piece of
ground mounted equipment (e.g.
busbar, transformer…)
If wall is greater Vertical articulation if permitted
than 10-feet
Line-of-sight study is required Will comply
Cannot exceed 15% of wall’s total Will comply
height.
Substations Maximum of 10 feet in height, with a Will comply
Internal to a Site decorative louvered, slatted or
(Not adjacent to perforated upper screen, no more
public right-of- than 75% opaque, mounted above
way) the masonry wall; OR
A fully decorative louvered, slatted or Will comply
perforated screen, no more than 75%
opaque.
11-31-37.F.8 Undergrounded as deemed
Utilities necessary by the Development
Services Department in its sole
discretion and approved by the
applicable utility provider
Additionally, NextEra will comply with the Operational Requirements established in
Section 11-31-37.G.1-3 of the BESS Ordinance, which includes Ongoing Sound Studies,
Augmentation Approval and Change in Ownership or Operator.
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12. Conclusion
This proposed BESS facility, and the entire Ellsworth Energy Center project, will provide a
range of benefits for the City of Mesa. The facility will contribute to the provision of
available, reliable, and affordable energy for the City and surrounding areas, where
electrical demand is increasing while increasing Valley temperatures are straining the
power grid.
Ellsworth II is in compliance with the Mesa Zoning Ordinance and advances the General
Plan placetype designation, as well as the Mesa Gateway Strategic Development Plan
elements.
The applicant and NextEra respectfully request approval of this rezoning request.
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