Solar Companies in Sonoma, CA: Who Installed the Most Systems in 2025

Installers who connected the most home solar systems in Sonoma in 2025

Counts from utility records, not a ranking or endorsement. Check each license's status and complaint history on the CSLB's Check a License page (checked Sept. 24, 2026).

Source: California Distributed Generation Statistics (CPUC), Interconnected Project Sites data set, data through May 31, 2026 (checked Sept. 24, 2026).

Home solar in Sonoma by the numbers

PG&E approved 196 home solar systems in Sonoma in 2025, from 61 installers; the top three were named on 39% of them. The busiest year since 2021 was 2023, with 311 (2025: -37%). Another 86 were approved from January through May 2026.

2025 mix: 34% leased or on a power purchase agreement, 66% owned by the household; 49% with a battery; median size 6.44 kW DC. Sonoma County: 33% leased or PPA, 47% with a battery, median 5.75 kW.

Hiring a solar company in Sonoma

Solar companies in Sonoma pull permits from one of two offices, depending on the address: the City of Sonoma, which runs SolarAPP+ and usually issues permits in 2 to 5 business days, or Permit Sonoma for the unincorporated county. Either way, Sonoma Clean Power supplies the generation and PG&E delivers it. Get three written bids that name the right permit office and your actual bill, then compare them.

Start with your Sonoma electricity bill

Sonoma homes get delivery from PG&E and generation, by default, from Sonoma Clean Power, the community choice provider for Sonoma and Mendocino counties; the Energy Commission's map places the City of Sonoma inside both. Have each bidder model your actual Sonoma Clean Power and PG&E enrollment and show the two halves of the bill separately.

City of Sonoma or Permit Sonoma: which office issues your permit

Inside city limits, the City of Sonoma uses SolarAPP+ for residential, roof-mounted, retrofit photovoltaic systems and storage, which gives an instant plan review; SolarAPP+ charges its own processing fee. The City runs a separate expedited permit for battery energy storage systems. It says approved permits usually issue in 2 to 5 business days and that inspections can often be done the next business day, requested by calling 707-938-3681 at least a business day ahead with the permit number, address and inspection type.

Outside city limits, Permit Sonoma handles the job. Its SolarAPP+ route covers rooftop systems of 10 kW or less on one- and two-family homes, is open to licensed contractors only (owner-builders use the regular process), and asks for the system's fire classification and label locations, since all roof-mounted systems must meet State Fire Marshal requirements. Inspection requests made before midnight are usually scheduled for the next business day. Ask each bidder which office your address belongs to before comparing timelines.

Sonoma Clean Power's rules for new solar

Sonoma Clean Power's net energy metering program is closed to new customers, so a new system goes on its Solar Billing Plan. Each spring SCP pays customers for surplus energy sent to the grid at the Net Surplus Compensation rate, up to $5,000 a year: more than $200 arrives as a check, and $200 or less appears as a bill credit.

That cap and those thresholds only matter if a system overproduces for the year, which a system sized to your usage should not. The bigger question for a Sonoma bid is how much of your own daytime use it covers, so ask each bidder to show monthly production next to your monthly use.

What a Sonoma quote needs to explain

A comparison to ask for

Give each bidder the same year of bill history and the same roof layout. Then compare the system design, roof and electrical work, the permit route (city SolarAPP+ or Permit Sonoma), the contract total and the remaining Sonoma Clean Power and PG&E charges side by side. A lower monthly payment does not show the full agreement.

Verify the company behind the Sonoma quote

Match the business name and license number on each Sonoma proposal to the CSLB record, then use our contractor verification steps, the quote comparison guide and the PPA, loan, lease and cash comparison.

Sonoma solar quote questions