AriSEIA Submits 4th Round of Comments on Surprise BESS Ordinance

Mayor and Members of the City Council
City of Surprise
16000 N. Civic Center Plaza
Surprise, AZ 85374
 
RE: City of Surprise Battery Energy Storage System (BESS) Text Amendment, Case FS23-1041
 
Dear Mayor and Councilmembers:
 
The Arizona Solar Energy Industries Association (AriSEIA) appreciates the opportunity to provide continued comments on the City of Surprise draft Battery Energy Storage System (BESS) ordinance. AriSEIA previously submitted written comments on November 14, 2024, February 18, 2025, and January 5, 2026. AriSEIA representatives also attended both public meetings regarding this ordinance, as well as the Planning and Zoning Commission work session on May 21, 2026. We appreciate the City’s continued engagement and the revisions reflected in the latest draft.
 
The current draft reflects meaningful progress, including alignment with National Fire Protection Association (NFPA) 855 for internal battery cabinet separation requirements. AriSEIA also appreciates the City’s efforts to create a regulatory pathway for utility-scale battery storage through the overlay framework. Several targeted revisions remain necessary, however, to ensure the ordinance is appropriately scoped, workable, and supportive of responsible energy infrastructure development.
 
Applicability and Scope 
The most significant remaining issue is applicability. While the ordinance now excludes batteries located within single-family and multi-family residential projects, it also includes accessory battery energy storage systems within the ordinance’s scope. By contrast, Mesa expressly excludes accessory systems from its utility-scale BESS requirements when those systems serve the enterprise functions of the on-site property owner or tenant and meet defined size thresholds. Mesa City Code § 11-31-37.[1]
 
As drafted, the ordinance could apply not only to utility-scale battery storage projects, but also to commercial, industrial, institutional, and backup power systems serving on-site load. This creates substantial and likely unintended consequences for commercial battery storage paired with rooftop solar, school or hospital backup power systems, industrial behind-the-meter storage, and other customer-sited installations. These systems are fundamentally different from utility-scale infrastructure and should not be subject to the same zoning framework.
 
Zoning ordinances should be clear on their face. Reliance on future interpretation or enforcement discretion creates risk of inconsistent application, appeals, and unintended barriers to distributed energy deployment. Maricopa County addresses this issue by expressly distinguishing utility-scale systems from customer-sited systems. AriSEIA recommends replacing the current applicability language in Chapter 101, Article II with the following:
 
“For purposes of this ordinance, a BESS shall be considered utility-scale when designed for energy market participation or grid services and when not intended to primarily serve on-site end-use load. Residential, commercial, and industrial systems installed behind the customer meter or primarily serving on-site consumption shall be considered distributed energy resources and are exempt from Chapter 106.”
 
This revision would ensure that the ordinance applies only to utility-scale projects while avoiding unintended impacts to customer-sited storage systems. It would also provide clearer direction to applicants, staff, and the public regarding which systems are subject to the overlay framework.
 
Setbacks and Separation Requirements 
AriSEIA appreciates the Planning and Zoning Commission’s efforts to reduce the originally proposed residential separation requirements. However, the currently recommended framework remains too restrictive. The American Planning Association has identified BESS-specific setbacks generally ranging from 50 to 150 feet. Am. Plan. Ass’n, Zoning Practice 10 (Mar. 2024).[2]
 
Maricopa County requires battery energy storage units to be setback a minimum of 100 feet from all lot lines. Maricopa County Zoning Ordinance art. 603.10.[3] Buckeye requires a 150-foot separation from residential properties, measured from the BESS facility to the nearest residential structure, building setback line, or residential property line depending on site conditions. Buckeye, Ariz., Development Code § 5.8, Commercial and Industrial Use Specific Standards, Battery Energy Storage Systems.[4]
 
Against that backdrop, a combined 250-foot requirement exceeds both Arizona peer jurisdictions and the planning benchmarks identified by the American Planning Association. AriSEIA recommends that 150 feet be treated as the maximum separation requirement. If the City determines that a residential separation requirement is warranted, AriSEIA recommends replacing the current setback and separation language with the following:
 
“A utility-scale BESS shall be located no closer than one hundred fifty feet (150’) from an existing residential dwelling unit, measured in a straight line from the outermost battery cabinet, enclosure, or associated battery equipment to the nearest exterior wall of the dwelling.”
 
This approach directly addresses compatibility concerns without creating effective barriers to otherwise appropriate development. It also avoids stacking multiple setback and separation requirements in a way that exceeds relevant safety and planning benchmarks.
 
Noise Standard 
The revised ordinance replaces the prior measurable noise threshold with a requirement that the BESS generate no noise perceptible beyond the site boundaries. This creates a less workable and less objective standard than the prior draft. “Perceptible” is inherently subjective. Perception varies based on ambient conditions, time of day, surrounding land uses, and individual sensitivity. Nearly any infrastructure may generate detectable sound under some conditions. A subjective perception standard creates uncertainty for applicants, staff, and enforcement alike and does not provide a clear compliance framework.
 
AriSEIA recommends replacing the current language with an objective, measurable acoustic standard. Consistent with prior AriSEIA recommendations, a 65 dBA limit at the project boundary would provide a clearer and more administrable framework while avoiding subjective enforcement disputes. AriSEIA recommends replacing the current language with the following:
 
“Operational noise attributable to the BESS shall not exceed 65 dBA at the project boundary, as demonstrated by a study prepared by a qualified third-party acoustical engineer.”
 
This approach provides an objective and enforceable standard while recognizing that battery storage systems are industrial infrastructure and should be regulated using measurable performance criteria rather than subjective perception-based requirements.
 
Administrative Flexibility 
The revised draft requires modifications that change or expand site design beyond what was approved in the original rezone application to return through another Type 3 rezone process. This is unnecessarily restrictive and impractical.
 
Battery storage projects evolve during engineering, procurement, and permitting. Equipment specifications, fire safety design, and layout details often change as projects mature. Requiring full rezoning for design refinements that do not alter the core characteristics of an approved project creates unnecessary delay, cost, and uncertainty. A workable ordinance should preserve public safety while allowing reasonable flexibility for routine project evolution.
 
AriSEIA also recommends that the ordinance include a limited waiver mechanism for projects that substantially comply with the ordinance but require relief from a specific provision. Without that flexibility, otherwise appropriate projects may be blocked based on rigid application of individual requirements, even where equivalent safety and compatibility outcomes can be achieved.
AriSEIA recommends replacing the current language with the following two provisions:
 
“Administrative approval may be granted for modifications that do not increase the approved project footprint, reduce required setbacks, increase approved nameplate capacity, or materially alter approved access, emergency response, or fire protection features.”

“The Planning and Zoning Commission may grant a waiver from specific ordinance requirements upon a finding that the proposed alternative provides equivalent or greater protection for public safety and compatibility with surrounding land uses.”
 
This approach preserves objective guardrails for routine project refinements while maintaining public oversight for requests that require deviation from specific ordinance standards.
 
Need for Timely Action 
AriSEIA encourages the City to make targeted revisions and move this ordinance forward promptly. As currently structured, battery storage projects cannot move forward in Surprise because there is no workable regulatory pathway for development.
 
That uncertainty carries real economic development consequences. Battery storage is increasingly important infrastructure that supports grid reliability, business investment, and economic growth. Maintaining an effective prohibition while ordinance issues remain unresolved creates a missed economic development opportunity for the City. The City can make targeted revisions now and adopt a workable framework this summer so that appropriately sited projects can move forward.
 
Conclusion 
AriSEIA supports reasonable, data-driven regulation of utility-scale battery energy storage systems. The City has made meaningful progress toward creating a pathway for these projects, but the ordinance should be revised to clarify applicability, avoid excessive cumulative setbacks, replace subjective performance standards, provide administrative flexibility, and move expeditiously toward adoption.
 
With these targeted revisions, the City can protect residents while establishing a clear, defensible, and practical framework for needed energy infrastructure. We appreciate the opportunity to continue working with the City toward that outcome.
 
Respectfully,
Autumn Johnson
Executive Director
AriSEIA 
(520) 240-4757
[email protected]

[1] Mesa Resolution 12441, dated December 1, 2025, available here https://www.mesaaz.gov/files/assets/public/v/1/business-development/devsvcs/codesords/bess-adoption-by-ref-doc.pdf.

[2] American Planning Association, Zoning Practice: Battery Energy Storage Systems, available here https://planning-org-uploaded-media.s3.amazonaws.com/publication/download_pdf/Zoning-Practice-2024-03.pdf.

[3] Maricopa County, Article 603.10, available here https://esd.maricopa.gov/DocumentCenter/View/4785/P-18---Zoning-Ordinance-PDF?bidId=.

[4] City of Buckeye, Chapter 7, Development Code 3.2, available here https://library.municode.com/az/buckeye/codes/code_of_ordinances?nodeId=CD_ORD_CH7DECO.