The Board of Supervisors of Fairfax County, Virginia, amended its zoning ordinance establishing a comprehensive regulatory framework for large-scale battery energy storage systems (BESS). The amendment, which became effective on March 18, 2026, integrates BESS into the county’s existing utility and zoning framework as a “light utility facility” and introduces specific use permissions, development standards and application requirements.
What Is a Large-Scale BESS?
The amendment defines a large-scale battery energy storage system as a facility consisting of rechargeable batteries, typically enclosed in a physical container, capable of collecting and storing electrical energy from the grid or an energy generation facility and then discharging that energy at a future time, with a maximum stored energy greater than 600 kWh. A facility is not classified as a large-scale BESS if it (a) has a total maximum stored energy of 600 kWh or less, or (b) is located inside a building with a separate principal use and primarily serves that use.
Where Are Large-Scale BESS Permitted?
The amendment sets out a district-by-district permissions framework:
- Residential districts (other than R-A): Permitted by special exception for all light utility facilities, including large-scale BESS, but only if co-located with an electrical substation or solar power facility.
- Commercial districts: Telecommunication facilities are permitted by right; all other light utility facilities, including large-scale BESS, require a special exception.
- I-2 districts: Telecommunication facilities are by right; all other light utility facilities permitted by special exception.
- I-3, I-4, I-5, and I-6 districts: All light utility facilities are permitted by right except large-scale BESS, which requires a special exception with modification of standards for electrical substations.
- Planned development districts (PDH, PRC, PRM, PCC): Large-scale BESS must be co-located with an electrical substation or solar power facility, whether permitted by development plan or special exception.
Key Development Standards
Setbacks
Setbacks are measured to the nearest BESS structure or associated equipment, not to a fence or wall:
- 100-foot minimum setback from all lot lines;
- 200-foot minimum setback from an abutting lot line of a residential district or a property developed with a residential use. For these purposes, a property developed with an international airport and its related uses is not treated as an R district.
Fencing and Screening
A fence or wall that is an integral part of a large-scale BESS may exceed the maximum fence or wall height otherwise applicable under the zoning ordinance. The amendment also updates the transitional screening and barrier requirements (Table 5108.2) to include large-scale BESS alongside solar power facilities, requiring appropriate screening when adjacent to residential and other sensitive uses.
Fire Safety and Noise
- Emergency Operations Plan: A final emergency operations plan must be approved by the Office of Fire Marshal prior to issuance of a building permit.
- NFPA and UL Compliance: Large-scale BESS must comply with NFPA 855 (Standard for the Installation of Stationary Energy Storage Systems) and UL 9540A (Standard for Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems), in addition to all other applicable codes and standards.
- Noise Study: Prior to site plan approval, a noise study must be submitted to the Zoning Administrator demonstrating compliance with the County Noise Ordinance (Chapter 108.1).
Emergency Operations Plan Requirements
Applications for large-scale BESS must include a preliminary emergency operations plan addressing, among other things:
- safe shutdown, de-energizing and isolation procedures under emergency conditions;
- inspection and testing of alarms, interlocks and controls;
- response to system alarms or out-of-range conditions, including shutting down equipment and notifying fire department personnel;
- emergency procedures for fire, explosion, release of liquids or vapors, or other dangerous conditions;
- response considerations similar to a safety data sheet;
- procedures for handling BESS equipment damaged in an emergency;
- schedules for drills and training exercises for local first responders.
Decommissioning Plan and Financial Security
A preliminary decommissioning plan certified by an engineer or contractor with demonstrated expertise in large-scale BESS removal must be submitted with the application. The plan must include, among other items:
- the anticipated life of the project and a narrative of decommissioning activities,
- mitigation procedures for hazardous materials release during decommissioning,
- estimated decommissioning cost in current dollars and the methodology for the estimate;
- contingencies for removing intact or damaged BESS components,
- a requirement that the owner or operator notify the Zoning Administrator at least 60 days prior to planned discontinued operations, and
- a site restoration plan prepared by a licensed engineer or surveyor
A final decommissioning plan must be submitted to the director prior to site plan approval. The estimated cost of decommissioning must be guaranteed by bond, letter of credit or other county-approved security, which must remain valid until full decommissioning is complete. Critically, the cost estimate must be recalculated every five years, and the security must be increased when the recalculated estimate exceeds the existing guarantee amount by 10%.
To discuss how these draft initiatives intersect with your objectives and how to engage effectively with Fairfax County as these initiatives evolve, contact the authors or a member of the Real Estate Transactions Practice Group.