Updated / CA residential estimate
California solar panel cost calculator
Estimate system size, panel count, gross cost, annual production, and savings using defaults for California. Enter an address or ZIP Code below to replace them with live location data.
Strong sun resource with high retail rates, but export compensation and utility rules vary materially.
State data baseline
- Planning sun hours
- 5.4 hours/dayState planning default used when API data is unavailable.
- PVWatts annual yield
- 1,504 kWhPer 1 kW system at 20% loss. Solar resource: 5.87 kWh/m²/day; 17.2% capacity factor.
- EIA residential rate
- $0.3474/kWhLatest state average: 2026-06.
- API baseline location
- Sacramento, CA 95814, USA38.5778, -121.4942
Server-side API snapshot, refreshed monthly. All three providers returned external data.Data sources and update notes
Decision brief
What changes the decision in California
These state-specific checks are not included in a generic national quote. Resolve them before comparing payback claims. Supporting rules and official references are collected at the end of this page.
- 01Before you sign
Model exports by time, not one retail-rate number
The Solar Billing Plan uses time-varying export credits. A flat export input is only a planning shortcut, and battery timing can materially change value.
- 02Before you sign
Check the mandatory disclosure package
Ask for the current CSLB disclosure documents and Solar Consumer Protection Guide before interconnection paperwork is submitted.
- 03Before you sign
Confirm property-tax timing
Section 73 contains installation-date and ownership-change rules, including provisions tied to January 1, 2027. Verify qualification with the county assessor.
Verified state policy
What can reduce your cost in California
Review these 4 statewide or utility-level policy signals before comparing net cost. They are not automatically applied because eligibility, tax liability, utility territory, equipment, and program capacity can change.
Policy configuration verified .
Policy sources- Broad state solar cash rebate
$0 statewide
California does not offer one broad cash rebate to every residential solar customer. Income-qualified and utility-specific programs may still apply.
- Solar property assessment exclusion
100% of qualifying added value
A qualifying system completed before January 1, 2027 does not increase the property's assessment. California treats this as a new-construction exclusion, not a general property-tax exemption.
- SGIP low-income solar and storage
$1,100/kWh storage + $3,100/kW solar
These listed equity rates require low-income eligibility, paired solar and storage, available program funds, and other SGIP conditions.
- Solar Billing Plan (NEM 3)
Hourly avoided-cost export credits
New customers of the major investor-owned utilities generally receive time-varying export credits rather than the full retail import rate.
Calculation walkthrough
How we calculate for California
A worked example using this page's baseline assumptions. Calculator results above change when you edit the inputs.
Baseline inputs
Illustrative 1,000 kWh/month household
- Solar resource
- 5.150 peak sun hours/day
- Modeled system loss
- 20% loss / 80% delivered
- Household electricity use
- 12,000 kWh/year
- Energy value
- $0.3474 retail / $0.06 export
- 01
Annual output per 1 kW
Location and production losses
5.150 h/day × 365 days × 80% delivered
1,504 kWh/year
- 02
Required system capacity
Annual demand divided by output
12,000 kWh ÷ 1,504 kWh per kW
7.98 kW
- 03
Energy-based panel count
Rounded up; entered usable roof area can cap the result
7.98 kW ÷ 0.4 kW per panel → round up
20 panels
8 kW
- 04
Estimated first-year value
Retail offset plus export credit
12,000 kWh × $0.3474 + 29 kWh × $0.06
$4,171/year
Model notes and limitationsSources and scope
Production baseline
NLR PVWatts v8 modeled a 1 kW array at 20° tilt and 180° azimuth for Sacramento, CA 95814, USA.
Energy valuation
Self-consumed production offsets the retail rate. Production above annual use is valued at the configured export rate; utility tariffs may use different timing or settlement rules.
Not included
Roof shading, structural conditions, hourly tariffs, financing, maintenance, incentives, and tax eligibility require separate verification.
California FAQ
Data updated: 2026-08-11. API baseline: Google Geocoding API, EIA Open Data API v2, and NLR PVWatts v8. Policy assumptions should be verified before purchase using the sources below.
Sources & verification
Review the original API, statute, regulator, or program documentation before relying on an estimate for a purchase, tax filing, or contract.
Data sources
Geocoding, residential electricity rates, and solar production inputs.
3 sources · Updated 2026-08-11
Data sources
- D1
Address normalization and coordinates
Google Geocoding API - D2
Residential electricity rate
EIA Open Data API v2 - D3
Solar production model
NLR PVWatts v8
State rules
Official references behind the state-specific decision checks.
3 primary references
State rules
- R1
Model exports by time, not one retail-rate number
CPUC Solar Consumer Protection Guide - R2
Check the mandatory disclosure package
CPUC CSLB disclosure requirements - R3
Confirm property-tax timing
CA Revenue & Taxation Code § 73
Incentives
Tax, rebate, and compensation sources used for policy summaries.
4 policy sources · Reviewed Aug 11, 2026
Incentives
- P1
Broad state solar cash rebate: $0 statewide
California Solar Consumer Protection Guide - P2
Solar property assessment exclusion: 100% of qualifying added value
California State Board of Equalization - P3
SGIP low-income solar and storage: $1,100/kWh storage + $3,100/kW solar
California Public Utilities Commission SGIP - P4
Solar Billing Plan (NEM 3): Hourly avoided-cost export credits
California Public Utilities Commission
