Battery storage rules: Arizona
Arizona is among the top 3 states for utility-scale battery storage (Arizona Corporation Commission news release, October 3, 2025). The Commission describes its role over storage as narrow, and zoning decisions are made by local governments, so siting depends on the city or county.
No state moratorium: Mesa requires 1,000 ft from homes
No Arizona law pauses battery storage projects, and siting is decided by local zoning. Mesa set a 1,000 ft separation from residential uses in January 2026. Ask your city or county planning department whether any pause or restriction applies to your site. Mesa City Council minutes, January 12, 2026, item 8-a (Ordinance No. 5976)
Fire and building codes in force
- State Fire Code: A.A.C. R4-36-201 incorporates the International Fire Code by reference, and the codified text reviewed names the 2018 edition. Fire districts and cities adopt their own editions subject to State Fire Marshal review. Ask your fire district or city fire department which IFC edition and local amendments apply to your site.
- Phoenix adopted the 2024 IFC with city amendments, effective February 17, 2026, including local amendments to Section 1207 (energy storage systems) (Phoenix Fire Code 2024 amendment packet).
- Tucson's 2024 Fire Code amendments list no changes to Chapter 12 (Tucson 2024 Fire Code Amendments).
How a project is permitted
The state Line Siting Committee reviews "plants" of 100 MW or more, but the statute defines plants as thermal electric, nuclear or hydroelectric generating units; battery storage is not listed (A.R.S. 40-360). The Commission's Chair said its authority over non-thermal resources such as storage "hasn't been significantly updated since 1971" (ACC news release, October 3, 2025). Siting is therefore mostly local zoning. SB 1348 (2025), enacted as Chapter 99, lets cities and towns designate a reviewer for fire plans on municipal and private buildings, with a 60-day review deadline.
Setbacks and spacing
- Mesa: 1,000 ft separation from residential uses for battery energy storage facilities, adopted by the City Council on January 12, 2026, by a 6-1 vote (Ordinance No. 5976). Council members said the distance would be revisited as technology and NFPA 855 evolve. Local ordinance Mesa City Council minutes, January 12, 2026, item 8-a (Ordinance No. 5976)
- Maricopa County: two rezoning cases on the Board of Supervisors' December 10, 2025 agenda (Z250015 and Z250028) carry a condition of a 100 ft minimum setback for battery energy storage systems. Ask the county planning department what the current zoning ordinance requires for your site. Local ordinance Maricopa County Board of Supervisors agenda, December 10, 2025, cases Z250015 and Z250028
- Other Arizona cities and counties set their own separation distances. Ask your city or county planning department whether a separation distance applies to your site. Local ordinance Arizona Corporation Commission news release, October 3, 2025 (zoning decisions are local)
Legislation
- HB 2618 (2023) — solar and wind decommissioning, incl. battery storage removal (vetoed): Decommissioning rules for solar and wind facilities, including battery energy storage system removal. Vetoed. Arizona Senate fact sheet for H.B. 2618 (amended/vetoed), 56th Legislature
- SB 1348 (2025) — city review of fire plans (enacted): Lets cities and towns designate a reviewer for fire plans on municipal and private buildings, with a 60-day review deadline, and sets up phased permitting through the Office of the State Fire Marshal. Enacted as Chapter 99, Laws 2025. Laws 2025, Chapter 99 (S.B. 1348); Arizona Senate fact sheet for S.B. 1348
Reported incidents
- McMicken, Surprise, April 19, 2019: four firefighters were injured in an explosion at the battery facility (UL FSRI investigation report). UL FSRI (McKinnon, DeCrane, Kerber), July 2020, DOI 10.54206/102376/TEHS4612
- McMicken — what the investigation found: the DNV GL report for APS found one failed cell started cascading thermal runaway; the clean-agent suppression worked as designed but could not stop it; there were no thermal barriers between cells, no venting for accumulated flammable gas, and no emergency plan steps for this scenario; it recommended codes address cascading thermal runaway directly. DNV GL report No. 10209302-HOU-R-01, July 18, 2020, pp. 1-2
Storage in this place
- Market context (ACC, May 2025): nearly 3,900 MW operating, with 3,807 MW more planned (ACC news release, October 3, 2025, citing EIA).
Places within
- Mesa, AZ — battery storage facilities 1,000 ft from homes
Sources
- Arizona Administrative Code Title 4, Ch. 36 — State Fire Code Arizona Secretary of State
- Phoenix Fire Code 2024 amendment packet City of Phoenix
- Tucson 2024 Fire Code Amendments City of Tucson
- A.R.S. 40-360 — Line Siting definitions Arizona Legislature
- Mesa City Council minutes, January 12, 2026 (item 8-a, Ordinance No. 5976) City of Mesa
- ACC — Arizona now among the top three states for utility-scale battery storage (2025-10-03) Arizona Corporation Commission
- SB 1348 (2025) — Senate fact sheet, as passed House Arizona Legislature
- HB 2618 (2023) — Senate fact sheet, as vetoed Arizona Legislature
- Maricopa County — news release (zoning ordinance update, 2025-12-10) Maricopa County
- Maricopa County Board of Supervisors agenda item, 2025-12-10 (Z250015, Z250028) Maricopa County
- DNV GL — McMicken BESS event technical analysis for APS (2020) DNV GL for APS
Check a specific system
For a proposal or a system you're evaluating, answer a few questions in BESScheck: you get the rules that apply here, a checklist of what to ask, and the sources behind each line.