Vacaville Planning Commission recommends ordinance banning lithium‑ion for large battery storage and tightening siting rules

The Vacaville Planning Commission on Jan. 20 voted to recommend that City Council introduce and adopt a new ordinance establishing land‑use, permitting and safety standards for battery energy storage systems (BESS) within city limits.

Staff said the ordinance is intended to give Vacaville locally enforceable standards as several large projects move through the California Energy Commission process. A December technology assessment identified two broadly relevant technologies — lithium‑ion chemistries (including lithium iron phosphate and nickel manganese cobalt) and nonflammable flow‑battery alternatives — and noted that lithium‑ion deployments are prone to thermal‑runaway risk while certain flow batteries are nonflammable.

In response, staff revised the draft ordinance to explicitly prohibit lithium‑ion chemistry for tier 2 and tier 3 systems, lengthen the buffer for sensitive uses from 300 feet to 500 feet, and require enhanced financial assurances and decommissioning bonds so the city can remediate a site in the event of bankruptcy or an incident. Staff also adjusted tier definitions so the ordinance would apply to systems with an aggregate energy capacity above a defined threshold and to close a draft‑language gap identified in public comment.

Opponents argued the ordinance should be clearer about disclosure and how the exclusion of lithium‑ion from the BESS definition would affect permitting paths; supporters applauded the lithium‑ion prohibition and tighter buffers as protective measures for nearby communities and agriculture. "I think it's really good that City of Vacaville voices its opinion on ... we want to keep Vacaville safe, and that includes no lithium ion," one resident said during public comment.

After public comment and technical questions about measurement (megawatts vs. megawatt‑hours), Commissioner's Vargas moved that the commission recommend Council adopt the CEQA exemption for the ordinance and introduce the ordinance amending Title 14 to add Chapter 14‑09271, including the lithium‑ion prohibition for tier 2/3 and the 500‑foot buffer; Vice Chair Wilkerson seconded. The motion passed unanimously on a roll‑call vote.

The Planning Commission’s recommendation will go to City Council for introduction and a first reading; subsequent steps will include any council direction, outreach to potentially affected stakeholders and coordination with state review processes.