In May 2024, the Vacaville City Council adopted a temporary moratorium on new large-scale Battery Energy Storage Systems (BESS) within city limits. At the time, city officials had begun receiving interest from developers exploring energy storage projects in the region, but Vacaville did not yet have specific regulations governing these facilities.
The temporary pause allowed the city to evaluate how modern battery storage projects should be located, permitted, and regulated before additional proposals moved forward.
Nearly two years later, that review has resulted in a new ordinance regulating battery energy storage facilities. In March 2026, the Vacaville City Council unanimously approved the ordinance after months of public meetings, technical studies, and community debate.
The ordinance introduces new rules governing where energy storage systems may be built and what safety requirements must be met before projects move forward.
For Vacaville residents, policymakers, and developers considering projects in the region, the central question has remained consistent throughout the process: how can communities deploy energy storage while protecting public safety and maintaining clear oversight of large infrastructure projects?
Vacaville’s Two-Year Review of Battery Storage
Vacaville first enacted its temporary moratorium on May 14, 2024, pausing new large-scale battery storage proposals within city limits while the city evaluated potential safety, land-use, and permitting concerns.
The moratorium was later extended through May 14, 2026, to give city officials time to complete a full policy review and draft permanent regulations governing these projects.
During this period, Vacaville conducted technical studies, held community meetings, and received input from residents, planning officials, and emergency responders. City staff also examined different battery technologies and the safety characteristics associated with large grid-scale energy storage facilities.
A draft ordinance regulating battery storage facilities was released for public review in late 2025, followed by hearings before the Planning Commission and City Council in early 2026.
The process culminated in the March 2026 vote, when the City Council adopted the final ordinance establishing new policies and development standards for battery energy storage projects in Vacaville.
What the New Ordinance Requires
The Vacaville ordinance introduces a set of rules governing the development of large battery energy storage facilities within city limits.
Key provisions include:
- A prohibition on lithium-ion battery storage systems for large front-of-the-meter energy storage projects.
- A minimum 500-foot buffer zone between battery facilities and sensitive locations such as homes, schools, and hospitals.
- Restrictions on where energy storage facilities can be located, limiting development to specific areas and preventing projects on certain previously developed sites.
- Hazard analysis and emergency response planning requirements that must be completed before projects receive approval.
- Decommissioning and financial assurance requirements to ensure facilities can be safely removed and sites restored if a project is retired.
The ordinance primarily applies to large utility-scale battery storage facilities, while smaller behind-the-meter systems used by homes or businesses are treated differently under the city code.
Vacaville officials say the goal of the ordinance is to provide clear standards for evaluating energy storage proposals while addressing safety concerns raised by residents and emergency planners.
Why the Community Had Safety Concerns
Battery storage projects became a major local issue as residents learned about the possibility of large energy storage facilities being built near homes or agricultural land.
Public meetings and community forums drew significant participation from residents concerned about the potential impacts of these projects.
Several issues emerged repeatedly during the review process.
Fire Risk and Thermal Runaway
Lithium-ion batteries store large amounts of energy in a compact space. In rare circumstances, an internal battery failure can trigger thermal runaway, a rapid temperature increase that releases heat and gases.
During the city’s review process, residents and officials asked how battery systems are designed to manage these types of failure scenarios and whether a failure in one battery cell could spread to other cells.
These questions are common in municipal reviews of battery energy storage projects because they influence both system design and facility siting.
Air Quality and Gas Management
Another concern raised during the review involved the release of gases during a battery failure event.
Under extreme heat conditions, lithium-ion batteries can produce toxic gases such as carbon monoxide and hydrogen fluoride. Public discussions focused on how battery systems detect and manage these gases and how surrounding communities would be protected if an incident occurred.
Emergency Response Preparedness
Emergency preparedness also played a major role in the review.
Battery incidents differ from traditional structure fires and can require specialized response procedures. City officials discussed how local fire departments would respond to a battery-related event and whether response planning should occur before projects are approved.
These discussions ultimately shaped the safety provisions included in Vacaville’s new ordinance.
Why Battery Storage Still Matters for Vacaville
While communities carefully evaluate safety standards for energy storage projects, battery storage continues to play an important role in modern power systems.
For residents and local businesses, the benefits often appear in practical ways.
Reliable Power
Battery storage helps stabilize the electrical grid during periods of high demand. When electricity use rises sharply in the afternoon or evening, stored energy can be released to support the grid.
This helps prevent overload conditions and reduces the risk of power disruptions for homes and businesses.
More Stable Electricity Costs
Energy storage can also help manage electricity costs. By storing energy when demand is lower and releasing it during peak hours, storage systems reduce the need for expensive peak generation.
In many applications, battery storage can reduce peak electricity demand by 20% to 40%.
Lower peak demand helps stabilize electricity prices and reduces the need for costly grid expansion projects that ultimately affect ratepayers.
Emergency Resilience
Battery storage can also support emergency preparedness. During storms, heat waves, or other grid disruptions, stored electricity can help maintain power for critical services.
Facilities such as hospitals, emergency shelters, water systems, and communication infrastructure can rely on stored energy to maintain operations during outages.
These benefits explain why many communities continue exploring energy storage as part of long-term energy planning.
How Engineering Design Addresses Safety Concerns
Many of the concerns raised during Vacaville’s review stem from how conventional battery systems manage heat, ignition risk, and gas release.
Most battery energy storage systems use either air cooling or liquid cooling within enclosed battery cabinets to regulate temperature during operation. These designs move heat away from battery cells through airflow or cooling loops, but the cells themselves still operate inside air-filled enclosures.
During a failure event, heat buildup and gas release inside these enclosures can create the conditions that allow thermal escalation or fire propagation.
For this reason, attention is increasingly shifting toward engineering approaches that eliminate the conditions required for ignition and gas exposure, rather than relying solely on emergency response planning.
How EticaAG Helps Communities Deploy Battery Storage Safely
EticaAG designs battery energy storage systems specifically to address the safety concerns that have driven many municipal reviews of conventional battery installations.
Two technologies form the foundation of this safety architecture: LiquidShield Immersion Cooling and HazGuard Gas Neutralization Technology.
LiquidShield Immersion Cooling
Traditional battery systems typically rely on air cooling or conventional liquid cooling to remove heat from battery cells. EticaAG’s LiquidShield immersion cooling uses a different approach.
Immersion cooling submerges the entire battery cell in a non-toxic dielectric fluid. The fluid transfers heat away from the cells and maintains stable temperatures across the system.
Immersion cooling also isolates the battery cells from oxygen. In the event of an internal cell failure, the liquid barrier prevents oxygen from reaching the cells.
Without oxygen, flames cannot form. This immediately suppresses flames and prevents ignition.
HazGuard Gas Neutralization Technology
Battery failure scenarios can produce gases such as carbon monoxide, hydrogen fluoride, and hydrocarbons. EticaAG’s HazGuard technology manages these gases inside the enclosure.
The system contains the gases, directs them through sealed pathways, and neutralizes hazardous compounds before air is released. The treated air leaving the system is inert and safe, protecting nearby residents, emergency responders, and surrounding infrastructure.
Integrated Safety Architecture
When LiquidShield and HazGuard operate together, the system provides multiple layers of protection.
Heat is controlled at the battery cell, ignition is prevented, and gases are neutralized before they can reach the surrounding environment.
These engineering outcomes directly address the safety concerns communities evaluate when reviewing battery energy storage projects.
A Clear Path Forward
Vacaville’s two-year review reflects the growing attention communities are paying to energy infrastructure safety.
Before approving large energy systems, cities want clear policies that protect residents, emergency responders, and the environment.
At the same time, energy storage continues to play a critical role in supporting reliable electricity, stabilizing energy costs, and strengthening grid resilience.
As technology evolves, engineering solutions that eliminate fire propagation and control hazardous gases will play an increasingly important role in helping communities deploy energy storage safely.
