California Solar Calculator — 2026 Costs & Payback
California is the largest US solar market by installed capacity (over 18 GW residential as of 2025), but the rules of the game changed dramatically with NEM 3.0 in April 2023. Export rates dropped roughly 75%, making battery storage essentially required for new installations to hit reasonable payback. Despite this, California's combination of $0.32/kWh average residential rates and 1,620 kWh/kW production keeps solar economics strong — the typical 7 kW system delivers $1,800–$2,400 in annual self-consumption savings before any battery export.
US Solar Payback Calculator — 2026
Get an accurate solar payback estimate for your state using NREL solar irradiance, EIA electricity rates, and the 30% federal Investment Tax Credit.
The numbers above are based on state averages. Real quotes vary by roof orientation, shading, panel type, and installer. Compare quotes from 3+ pre-vetted installers in your area — free, no obligation.
Highest electricity rates in the lower 48. NEM 3.0 (since April 2023) cuts export rates ~75%. Battery storage now near-mandatory for payback.
Methodology & sources
Solar irradiance per state: National Renewable Energy Laboratory (NREL) PVWatts PSM3 typical-year data, weighted state average for residential rooftops.
Electricity rates: EIA Form 826 monthly residential rates (most recent September 2025 data).
Federal ITC: 30% through 2032 under the Inflation Reduction Act (Section 25D).
State incentives: DSIRE (Database of State Incentives for Renewables & Efficiency) as of April 2026.
Inflation assumptions: 2.5% annual electricity price increase (EIA AEO 2024 reference case), 0.5% annual panel degradation (NREL standard).
Self-consumption assumption: 45% direct self-consumption without battery — typical for residential without storage.
Deep dive — solar in California
California-specific incentives in 2026: The Self-Generation Incentive Program (SGIP) still offers battery rebates of $200–$1,000 per kWh for low-income or wildfire-zone customers. The federal 30% ITC applies to both panels and storage. California has no separate state tax credit for solar, but solar systems are exempt from property tax reassessment under Proposition 13.
Top California utilities and their net metering quirks:
- PG&E (Northern + Central CA) — full NEM 3.0 rules, peak hours 4-9pm
- SCE (Southern CA inland) — same rules, slightly different rate schedules
- SDG&E (San Diego) — most expensive electricity in CA, fastest payback
- LADWP (Los Angeles city) — independent utility, kept retail-rate net metering
Best system size for CA in 2026: typically 6–9 kW for a single-family home with average bill $200–$300/month. Battery: 10–13 kWh.
California solar FAQ
Is solar still worth it in California with NEM 3.0?
Yes, but only with a battery for most homes. Without storage, payback stretches from ~7 years (NEM 2.0 era) to 11–13 years. Adding a 10 kWh battery keeps payback in the 6–8 year range and unlocks full self-consumption value at $0.32/kWh retail rates.
How much does a 7 kW solar system cost in California 2026?
Gross cost around $21,700 ($3.10/W × 7,000 W). After the 30% federal ITC: net $15,200. With a 10 kWh battery added: gross $35k, net post-ITC ~$24,500.
What is the average payback period in California?
For a system sized to current consumption with battery: 6–8 years. Without battery, 9–13 years depending on consumption profile and time-of-use rate plan.
Can I qualify for Proposition 13 property tax exemption?
Yes. California excludes the added value of a residential solar system from property tax reassessment for the original owner.