On Nov. 3, Solano County voters will decide Measure E, a countywide general tax that updates the business license tax on commercial energy and resource projects — and, for the first time, puts a square-footage tax on data centers in unincorporated Solano County. The tax would apply only to facilities outside city limits, but every registered voter in the county can vote on it. For every other local contest we have covered, see our Nov. 2026 election guide.

What a yes vote changes

According to the ballot question published by the Daily Republic and the impartial analysis summarized by California Choices, a yes vote would:

  • Raise the commercial wind turbine rate from $0.00003 to $0.00008 per kilowatt-hour — the first increase since the county set that tax in 1994.
  • Add a $0.00008 per kilowatt-hour tax on electricity from commercial solar energy systems.
  • Add a monthly capacity tax of $1.50 per megawatt-hour of approved storage capacity on front-of-the-meter battery energy storage systems, whether or not the batteries are charging or discharging.
  • Add a tax of $0.30 per thousand cubic feet of natural gas extracted.
  • Add an annual tax of $5 per square foot of gross floor area on data centers, including equipment-pad areas for behind-the-meter batteries and natural gas turbines that support a data center.

KQED reports the new rates would take effect Jan. 1, 2027, with yearly inflation adjustments (California Choices says CPI updates begin Jan. 1, 2028 and cannot lower rates). County staff estimate about $353,000 more a year for the General Fund. There is no sunset.

Why supervisors put it on the ballot

The Board of Supervisors voted 4-0 on July 28, 2026, to place the measure on the ballot; Supervisor John Vasquez was absent, the Press Democrat reported. Chair Mitch Mashburn framed the tax as a way to make state-backed energy and data-center projects pay for county services, telling colleagues he wanted it "as expensive as possible" for those uses. Speakers asked for a data-center ban; Mashburn said a tax came first, noting the state had already overridden local battery-storage limits, the Daily Republic reported.

KQED and California Choices both note there are no data centers in unincorporated Solano County today. Supporters say the $5-per-square-foot rate is insurance if facilities arrive, and that the 1994 wind tax has lost real value without inflation adjustments.

Supporters, opponents and what a no vote means

KQED lists Supervisors Cassandra James and Mitch Mashburn among yes supporters. Their pitch: update a 1994 wind tax, make energy and tech projects contribute locally, and keep the money in Solano rather than Sacramento or Washington.

On the no side, KQED lists Michael Nolan of the Solano County Taxpayers Association and Dixon resident Shari Borkin. Opponents warn a permanent tax expansion — including more than doubling the wind rate — could discourage clean-energy investment and raise costs that flow through to ratepayers and families, for a relatively small $353,000 gain.

  • Yes: Adopt the new and higher business license tax rates for the listed facilities in unincorporated Solano County.
  • No: Leave the 1994 wind rate and current code unchanged; no new solar, battery, gas-extraction or data-center business license taxes under this measure.

Measure E needs a simple majority. Related Solano and business-tax coverage includes our guide to city sales-tax measures in Fairfield, Vacaville and Rio Vista, Concord's Measure O business license tax, and Bay Area data center rules fights.