Solar Panel Cost in Windsor, CA (2026): $4.32/W Reported

Windsor homeowners who bought their own solar systems reported a median of $4.32 per watt between January 2025 and May 2026, across 59 systems. The middle half paid $3.18 to $6.41 per watt.

A 6.53 kW system, the median size connected in Windsor in 2025, comes to about $28,200 at that median, or $20,800 to $41,900 across the middle half.

Those are reported costs, not a quote, and no federal credit comes off a Windsor system finished in 2026: 26 U.S.C. §25D does not cover one whose installation is completed after December 31, 2025 (state and federal rules).

Median reported cost: $4.32/W; Windsor addresses, 59 systems
Middle half: $3.18 to $6.41/W; 25th to 75th percentile
Typical 6.53 kW system: $28,200; 6.53 kW × $4.32/W, before any incentive
Same system, middle half: $20,800 to $41,900; size: Windsor addresses, 2025 median

Source: California Distributed Generation Statistics (CPUC), Interconnected Project Sites data set, data through May 31, 2026, checked September 24, 2026. Homeowner-owned, solar-only systems of 1 to 25 kW; leases, PPAs and battery systems are left out (method). The CPUC notes these costs are not verified by the government.

California Rate Relief is a referral service. We are not a licensed contractor.

What a solar permit costs in Windsor

Windsor does not publish a dollar figure for a residential solar permit. Whatever it charges, Government Code §66015 limits a city to $450 for a home system up to 15 kW, plus $15 per kW above that, unless it adopts a written finding that its cost is higher.

What Windsor publishes: Windsor's Residential Solar Applications page says Symbium collects a service fee before sending the applicant to the Town's eTRAKiT system for the permit, but it states neither that fee nor the Town's own permit fee.
How to file: Yes. The Town's Symbium platform checks residential solar and energy storage applications for code compliance and allows instant permit approval, with the permit issued in eTRAKiT. Applications can still be sent by email or in person, with plan review of 1-3 business days, and every contractor needs an active Town business license before a permit issues.
Automated permit platform: Symbium

Sources: Town of Windsor, Residential Solar Applications (Building Division), checked September 23, 2026; California Energy Commission, Residential Solar Permitting Program data (SB 379 platform status as self-reported by each jurisdiction; data last updated August 3, 2026), checked September 23, 2026; Gov. Code §66015, checked September 24, 2026. Windsor in the California Solar Cost Index sets this fee beside every other city's.

Solar in Windsor: installs, leases and batteries

Home solar systems connected at Windsor addresses: 183 in 2021, 241 in 2022, 255 in 2023, 125 in 2024 and 143 in 2025. So connections peaked in 2023 and 2025 ran 44% below that peak. Another 59 were connected from January to May 2026.

Of the 143 systems connected in Windsor in 2025, 46% were leased or on a PPA, so a solar company owns them, and 54% belonged to the homeowner. 63% had a battery, more often than the 55% statewide. The median Windsor system was 6.53 kW, and 33 companies connected at least one.

Windsor beside Sonoma County and Statewide, 2025
	Windsor	Sonoma County	Statewide
Systems connected in 2025	143	2,388	145,404
Leased or on a PPA	46%	33%	45%
With a battery	63%	47%	55%
Median system size	6.53 kW	5.75 kW	6.15 kW
Median reported cost	$4.32/W (59)	$5.27/W (1,432)	$4.14/W (58,628)
Companies connecting systems	33	176	2,475

Source: CPUC DG Stats, data through May 31, 2026. Counts are home systems given permission to operate each year; a city means the service city on the application.

Your utility: PG&E

Windsor is billed by Pacific Gas and Electric Company (PG&E). PG&E's average residential rate is 33.7¢/kWh (June 2026 (unchanged since March 2026); rate tracker).

Sonoma Clean Power supplies generation for many Windsor addresses while PG&E delivers and bills; your bill shows which. Source: Sonoma Clean Power, Who We Are (governed by the Counties of Sonoma and Mendocino and cities including Petaluma, Santa Rosa and Windsor).

Before you compare proposals

The Windsor project checks that change the decision

Windsor gives instant solar and battery permits through Symbium and still accepts email or in-person applications with a short plan review. Sonoma Clean Power supplies generation and pays surplus each spring.

Ask the same three questions

Will the permit go through Symbium for instant approval, or by email with 1-3 business days of plan review?
Does the contractor hold an active Town of Windsor business license? No permit issues without one.
Does the bill model reflect Sonoma Clean Power's Solar Billing Plan terms on the E-ELEC rate?

Local checks

Symbium, then eTRAKiT

Symbium checks the application for code compliance, collects its service fee and sends the applicant to the Town's eTRAKiT system for the permit. Neither the service fee nor the Town's own fee is stated.

Plan review is still an option

Solar and storage applications can still be sent by email or in person, with plan review of 1-3 business days.

SCP's spring payout

Sonoma Clean Power, whose governing board includes Windsor, moves Solar Billing Plan customers to E-ELEC and pays surplus each spring up to $5,000, by check when it is over $200.

Related decisions

Local sources and limits

Town of Windsor — Residential Solar Applications — verified 2026-09-23. Symbium instant approval for residential solar and energy storage; Symbium collects a service fee (amount not stated) and sends the applicant to eTRAKiT for issuance; email or in-person applications get plan review of 1-3 business days; an active Town business license is required.
Sonoma Clean Power — Who We Are — verified 2026-09-23. The CCA for Sonoma and Mendocino counties, governed by elected officials from both counties and from cities including Petaluma, Santa Rosa and Windsor.
Sonoma Clean Power — Solar Billing Plan — verified 2026-09-23. Solar Billing Plan customers move to the E-ELEC rate with a $15-per-month base services charge; each spring surplus is paid at Net Surplus Compensation up to $5,000 a year, by check over $200 and as a bill credit at or below it.
California Energy Commission — Residential Solar Permitting Program data (SB 379) — verified 2026-09-23. Self-reported platform status per jurisdiction, data last updated August 3, 2026; the CEC says it does not certify compliance. Rows used for the Tier 3 cities: Santa Clara, Clovis, Berkeley, Concord, Richmond, San Clemente, Encinitas, San Marcos, Lakewood, Elk Grove, Mission Viejo, Victorville, Tulare, Yucaipa, Rocklin and Grass Valley (SolarAPP+); Glendale and Santa Barbara (custom platform); Saratoga and Vacaville (Symbium); Napa (without a platform); Gilroy, San Ramon, Redding and Yuba City (SolarAPP+); Windsor and Ventura (Symbium); Redwood City and Cupertino (SolarAPP+); Hollister (without a platform, deadline Sept 2024).

Before you sign

In Windsor the middle half of reported costs spans $3.18 to $6.41 per watt, and roof, panel work, equipment and contract terms explain most of that gap. California Solar Tax and Permit Rules for 2026 covers them, and the tax, lease and disclosure rules a Windsor contract follows.

Frequently asked questions

How much does solar cost in Windsor?

About $28,200 for a 6.53 kW system, at the $4.32 per watt median that Windsor owners reported (59 systems, January 2025 to May 2026; middle half $3.18 to $6.41). Source: CPUC DG Stats. No federal credit applies to a Windsor system finished in 2026.

What does a solar permit cost in Windsor?

Windsor states no single current figure (no figure published, checked September 23, 2026); Gov. Code §66015 caps it at $450 up to 15 kW unless the city adopts a written finding.

Which utility serves Windsor?

Pacific Gas and Electric Company (PG&E). Its average residential rate is 33.7¢/kWh, as of June 2026 (unchanged since March 2026).

Sources

California Distributed Generation Statistics (CPUC), Interconnected Project Sites data set, data through May 31, 2026 — checked September 24, 2026
CPUC, California Solar Consumer Protection Guide — checked September 24, 2026
26 U.S.C. §25D(h) and (e)(8)(A), residential clean energy credit — checked September 24, 2026
Windsor solar permitting — Town of Windsor, Residential Solar Applications (Building Division) — checked September 23, 2026
California Energy Commission, Residential Solar Permitting Program data (SB 379 platform status as self-reported by each jurisdiction; data last updated August 3, 2026) — checked September 23, 2026
California Government Code §66015(a), residential solar permit fees — checked September 24, 2026
Sonoma Clean Power, Who We Are (governed by the Counties of Sonoma and Mendocino and cities including Petaluma, Santa Rosa and Windsor) — checked September 23, 2026
PG&E average residential rate — CPUC Public Advocates Office, Q2 2026 Electric Rates Report, p.8, 20 — checked November 9, 2026

The tax, contract and permit rules every California city shares, with their statutes: California Solar Tax and Permit Rules for 2026.