Solar Panel Cost in San Marcos, CA (2026): $4.90/W Reported
By Chad SimpsonUpdated 8 sources citedSan Marcos, San Diego County
San Marcos homeowners who bought their own solar systems reported a median of $4.90 per watt between January 2025 and May 2026, across 461 systems. The middle half paid $3.00 to $6.74 per watt.
A 5.4 kW system, the median size connected in San Marcos in 2025, comes to about $26,500 at that median, or $16,200 to $36,400 across the middle half.
Those are reported costs, not a quote, and no federal credit comes off a San Marcos 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
- $4.90/W
- San Marcos addresses, 461 systems
- Middle half
- $3.00 to $6.74/W
- 25th to 75th percentile
- Typical 5.4 kW system
- $26,500
- 5.4 kW × $4.90/W, before any incentive
- Same system, middle half
- $16,200 to $36,400
- size: San Marcos 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 San Marcos
San Marcos' published permit fee for a home rooftop system is $124 ($57 plan check, residential rooftop solar + $67 permit, residential rooftop solar). Energy storage system: $52.
That is $326 under the $450 limit that Government Code §66015 sets for a home system up to 15 kW.
- What San Marcos publishes: San Marcos's Development Fees schedule, effective September 1, 2026, lists a residential solar system on a roof at $57 for plan check plus $67 for the permit, $124 in all, and an energy storage system at $52. A carport with solar is $980 for plan check plus $454 for the permit. SolarAPP+ charges its own processing fee.
- How to file: Yes. A homeowner can use the City's standard central-inverter or micro-inverter plans and apply online under "Roof Mounted Solar PV Expedited", which the City estimates at 1-3 business days. Contractors use SolarAPP+, need a City of San Marcos business license and attach a permit declaration form in the City's online permitting system, without which no inspection can be scheduled. Systems that qualify for neither submit full plans online, estimated at 5-10 business days.
- Automated permit platform: SolarAPP+
Sources: City of San Marcos, Solar Permits (Building Division), checked September 23, 2026; City of San Marcos, Development Fees, effective September 1, 2026 (Building: Residential Solar System on Roof; Carport w/ Solar; Electrical: Energy storage system), checked September 23, 2026; Gov. Code §66015, checked September 24, 2026. San Marcos in the California Solar Cost Index sets this fee beside every other city's.
Solar in San Marcos: installs, leases and batteries
Home solar systems connected at San Marcos addresses: 877 in 2021, 1,162 in 2022, 1,664 in 2023, 511 in 2024 and 439 in 2025. So connections peaked in 2023 and 2025 ran 74% below that peak. Another 243 were connected from January to May 2026.
Of the 439 systems connected in San Marcos in 2025, 34% were leased or on a PPA, so a solar company owns them, and 66% belonged to the homeowner. 0% had a battery, less often than the 55% statewide. The median San Marcos system was 5.4 kW, and 76 companies connected at least one.
| San Marcos | San Diego County | Statewide | |
|---|---|---|---|
| Systems connected in 2025 | 439 | 14,679 | 145,404 |
| Leased or on a PPA | 34% | 36% | 45% |
| With a battery | 0% | 0% | 55% |
| Median system size | 5.4 kW | 5.36 kW | 6.15 kW |
| Median reported cost | $4.90/W (461) | $4.84/W (11,130) | $4.14/W (58,628) |
| Companies connecting systems | 76 | 483 | 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: SDG&E
San Marcos is billed by San Diego Gas & Electric (SDG&E). SDG&E's average residential rate is 45.5¢/kWh (June 1, 2026; rate tracker).
Clean Energy Alliance supplies generation for many San Marcos addresses while SDG&E delivers and bills; your bill shows which. Source: SDG&E, Active CCAs (the cities Clean Energy Alliance and San Diego Community Power serve).
Before you compare proposals
The San Marcos project checks that change the decision
San Marcos charges $124 in City fees for a rooftop home system under its September 2026 schedule, so the permit is a small line in a San Marcos quote. The paperwork is where contractors differ.
Ask the same three questions
- Is the City permit line close to the published $124 for a rooftop system, plus $52 if a battery is included?
- Does the contractor hold a City of San Marcos business license and file the permit declaration form, without which the City will not schedule an inspection?
- Does the savings estimate use Clean Energy Alliance's 6-cent surplus rate and SDG&E's delivery charges?
Local checks
$124 for a rooftop system
The Development Fees schedule effective September 1, 2026 lists a residential rooftop solar system at $57 for plan check and $67 for the permit, and an energy storage system at $52. A solar carport is far more: $980 plan check plus $454 permit.
A homeowner route
A homeowner can use the City's standard central-inverter or micro-inverter plans and apply online as "Roof Mounted Solar PV Expedited", which the City estimates at 1-3 business days. Full plan review is estimated at 5-10 business days.
CEA's 6-cent surplus
Clean Energy Alliance pays net surplus at $0.06 per kWh, which it describes as slightly higher than SDG&E, sends a check for $100 or more, and rolls smaller amounts forward. The true-up falls on the anniversary of NEM enrollment.
Related decisions
Local sources and limits
- City of San Marcos — Solar Permits — verified 2026-09-23. Homeowners: City standard plans and the "Roof Mounted Solar PV Expedited" option, estimated 1-3 business days. Contractors: SolarAPP+, a City business license and a permit declaration form, required before an inspection can be scheduled. Full plan review estimated 5-10 business days.
- City of San Marcos — Development Fees, effective September 1, 2026 — verified 2026-09-23. Residential Solar System on Roof: plan check $57, permit $67. Carport w/ Solar: plan check $980, permit $454. Energy storage system (ESS): $52.
- SDG&E — Active CCAs — verified 2026-09-23. Names the cities served by Clean Energy Alliance and San Diego Community Power. A city missing from both lists has no active CCA named there.
- Clean Energy Alliance — Net Energy Metering — verified 2026-09-23. Net Surplus Compensation at $0.06 per kWh for excess over the 12-month period, described as slightly higher than SDG&E’s credit; checks for $100 or more, smaller amounts rolled forward; true-up on the NEM enrollment anniversary.
- 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 San Marcos the middle half of reported costs spans $3.00 to $6.74 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 San Marcos contract follows.
Frequently asked questions
How much does solar cost in San Marcos?
About $26,500 for a 5.4 kW system, at the $4.90 per watt median that San Marcos owners reported (461 systems, January 2025 to May 2026; middle half $3.00 to $6.74). Source: CPUC DG Stats. No federal credit applies to a San Marcos system finished in 2026.
What does a solar permit cost in San Marcos?
$124 for a home rooftop system on San Marcos' published schedule (checked September 23, 2026); the state limit is $450 up to 15 kW under Gov. Code §66015.
Which utility serves San Marcos?
San Diego Gas & Electric (SDG&E). Its average residential rate is 45.5¢/kWh, as of June 1, 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
- San Marcos solar permitting — City of San Marcos, Solar Permits (Building Division) — checked September 23, 2026
- City of San Marcos, Development Fees, effective September 1, 2026 (Building: Residential Solar System on Roof; Carport w/ Solar; Electrical: Energy storage system) — checked September 23, 2026
- California Government Code §66015(a), residential solar permit fees — checked September 24, 2026
- SDG&E, Active CCAs (the cities Clean Energy Alliance and San Diego Community Power serve) — checked September 23, 2026
- SDG&E average residential rate — CPUC Public Advocates Office, Q2 2026 Electric Rates Report, p.8, 24 — 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.
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