Solar Panel Installation Cost in Marin County (unincorporated), CA: what the permits say

How much does solar panel installation cost in Marin County?

The usual solar & battery job filed with Marin County is $29,222, from 1,335 priced permits, October 2023 through September 2026. The middle half of firms usually file between $17,952 and $38,536. Half of jobs were filed for less, half for more. A filed value is what the contractor wrote on the permit, not a quote or the final bill.

What the spread looks like

Approximately, from each firm's own spread: every firm's range of filed values, weighted by its 1,335 priced permits across 199 firms, pooled into one. Half of Marin County (unincorporated) solar & battery permits were filed between $16,500 and $45,400.

By home value

Firms split into thirds by the usual value of the homes they work on, with each third's usual filed value weighted by permits. Home values: Marin County assessed land and improvement values from MarinMap parcels (Proposition 13 values, which usually sit well below market value). Under Proposition 13 a home bought decades ago can carry a value far below what it would sell for today, so treat the home-value matching and the price-versus-similar-jobs comparison as rough.

Busiest firms and what they usually charge

Top 10 by permits in the last 12 months. Usual is each firm's middle filed value; middle half is the range its middle half of jobs were filed in. Busy is not the same as careful: pick what you value to build a list.

Why filed values run low or high

• The 10 busiest firms usually file $29,597; the 172 firms with fewer than 10 permits usually file $22,865.
• Firms working on the most expensive third of homes (usual home value $1,887,638 and up) usually file $18,000, against $21,154 for the least expensive third.
• One permit type covers small and large jobs: 1 in 10 solar & battery permits is filed under $7,800 and 1 in 10 over $62,900, 8 times as much.
• 99.7% of the 1,339 permits carry a value; the 4 without one are left out of every figure here.

When to schedule solar installation in Marin County

Marin County files the fewest solar & battery permits in June (69 against an average month of 100) and the most in October (182). If you can choose, ask for quotes in a quiet month. We have no prices by month, so this is about crews' schedules, not a discount. When each trade is busiest in Marin County →

Guides for this trade

• Hiring a solar installer: 5 red flags and 10 questions, checked against solar permits in 41 cities
• The best month to start electrical, HVAC and solar work (by city)
• What's a good completion rate for a contractor? The benchmarks from 12 trades and cities
• How to check a contractor's license in California

All guides →

Common questions

• How many quotes should I get for a solar & battery job in Marin County (unincorporated)?At least three. In the permit record the middle half of Marin County (unincorporated) solar & battery firms usually file between $17,952 and $38,536 a job, so two ordinary firms can sit 2.1 times apart and both be normal for Marin County (unincorporated). A third quote shows which one is the outlier. Filed values are what contractors wrote on permits, not quotes, so use them to judge the spread, not to price your own job.
• What range is normal for solar & battery jobs in Marin County (unincorporated)?Half of permits were filed between $16,500 and $45,400; 8 in 10 between $7,800 and $62,900. These are approximate, pooled from each firm's own spread.
• How much do solar installers charge in Marin County?The usual solar & battery job is filed at $29,222; the middle half of firms usually file between $17,952 and $38,536. The 10 firms with the most permits in the last 12 months usually file $29,597, about the same as the usual. See every firm's usual job →
• Why is this different from the per-watt prices I see online?Online prices are quoted per watt. A filed value is one number for the whole job on one permit, often many watts plus the work around them, and the Marin County file does not record how many each job covered, so we can't turn $29,222 into a price per watt.
• How much is the solar & battery permit fee in Marin County?Marin County's published base fee is Residential Rooftop Photovoltaic Installations: $148.00 (Marin County Permit Base Fees, read October 2026). These are base fees; the County adds impact fees and taxes, and other approval agencies can charge their own. The fee is separate from the contractor's price.
• Do bigger houses get bigger bills?Not in the file: firms working on the upper third of homes by value usually file $18,000, the lower third $21,154.
• Where does this data come from?Marin County Community Development Agency building permits on homes in unincorporated Marin (the County's open-data permit and inspection files), read October 2026. How the records work in Marin County (unincorporated) →