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

Installers who connected the most home solar systems in Napa 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 Napa by the numbers

PG&E approved 470 home solar systems in Napa in 2025, from 88 installers; the top three were named on 38% of them. The busiest year since 2021 was 2022, with 826 (2025: -43%). Another 236 were approved from January through May 2026.

2025 mix: 36% leased or on a power purchase agreement, 64% owned by the household; 52% with a battery; median size 6.32 kW DC. Napa County: 36% leased or PPA, 49% with a battery, median 6.14 kW.

Hiring a solar company in Napa

Solar companies in the City of Napa get residential solar and battery backup permits over the counter, by walk-in, Monday through Thursday, with an active City of Napa business license and a signed contract with the homeowner. The City reports no automated SolarAPP+-style platform to the Energy Commission. PG&E delivers the power and MCE supplies the generation. Compare at least three written bids built on your own bill.

Start with your Napa electricity bill

Napa is an MCE member city, so a Napa bill carries PG&E's delivery charges and MCE's generation charges on one statement. MCE enrolls solar customers in its own program automatically, Net Energy Metering for systems applied for by April 14, 2023 and its Solar Billing Plan after that, and pays annual surplus at the Net Surplus Compensation rate plus $0.02 per kWh. Have each bidder model both halves from your own bill.

Napa's over-the-counter solar permit

Where many Bay Area cities now issue solar permits instantly online, the City of Napa's Building Division handles residential solar and battery backup systems at the counter. Walk-ins are taken Monday through Thursday between 8:30 a.m. and 3:30 p.m. The applicant brings one application per project and two full sets of plans: title page, site plan, structural calculations, single-line electrical diagram, attachment details, footing details for a ground mount, and the equipment cut sheets.

Two requirements catch applicants out. The address must be inside city limits rather than unincorporated Napa County, and the contractor must hold an active City of Napa business license, without which no permit is issued. The City also wants a signed contract with the homeowner, in paper or electronic form, and any revision needs both the original approved plans and the new ones.

How MCE credits a Napa solar home

MCE enrolls solar customers automatically. On its Net Energy Metering program, for systems whose applications were completed by April 14, 2023, credits build at retail rates through the year and are settled at MCE's annual spring cash-out, where surplus is paid at the Net Surplus Compensation rate plus $0.02 per kWh. Newer systems are on MCE's Solar Billing Plan for generation and PG&E's for delivery.

PG&E still sends the bill and trues up its delivery charges on its own schedule. A proposal that shows one annual savings number is hiding that split; ask for the MCE and PG&E portions separately.

What a Napa quote needs to explain

A comparison to ask for

Because Napa permits are issued in person, ask each bidder who will take your plans to the counter, whether its business license is active, and how quickly after contract signing it can do so. The City asks for a signed contract with the homeowner at submittal, so the permit step comes after you commit, not before.

Verify the company behind the Napa quote

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

Permit fees and the filing route are on the Napa solar cost and permit page.

Napa solar quote questions