Solar calculator for California
Panels, system size, cost and payback for California, from your own power bill.
The average California home uses 503 kWh a month and pays 32 cents per kWh, which puts California at among the highest electricity prices in the country, which is what makes solar pay back faster. California has both a heating and a cooling season, so the bill swings both ways and a full year of bills gives a better answer than one month. A south-facing fixed array there makes about 1,677 kWh per installed kW a year, and the worst winter month still gets 4.05 peak sun hours a day. Drop in your own bill below and the numbers on this page are replaced by yours.
A worked example for California
Take the average home: 503 kWh a month, which is 6,036 kWh a year, at 32 cents per kWh (EIA, 2024 residential averages, as of 2026-11). Sized to cover all of that use, the tool returns 3.6 kWdc and 9 panels, needing about 189 square feet of roof. The installed estimate is $8,962 (national median, EnergySage H2 2025), yearly savings are about $1,932, and simple payback is 4.6 years, with no incentive applied.
Sun and yield in California
We use 1,677 kWh per installed kW per year for California, from NREL PVWatts v8 for the state's largest city at a 20 degree south-facing tilt (via TheGreenWatt, as of 2026-11). The darkest month averages 4.05 peak sun hours a day, which matters if you plan to go off-grid or size a battery. A different roof angle or heavy shade changes this, so treat it as a starting point.
Incentives
The 30% federal tax credit ended for homeowner purchases after December 31, 2025, so none is applied here. See the tax credit guide. Look up California and your own utility for net metering terms and any local programs before relying on a payback number.
Planning estimate. Permits, interconnection approval and a licensed electrician are required for grid-tied systems.
Questions
How many solar panels does a California home need?
The average California home uses 6,036 kWh a year (EIA 2024). At about 1,677 kWh per installed kW, covering all of it takes 3.6 kWdc, or 9 panels. Your own bill will move that up or down.
How much does solar cost in California?
For the average-home example the installed estimate is $8,962 at the national median of $2.49 per watt (EnergySage, H2 2025, as of 2026-11). We have no sourced California price multiplier, so local quotes will differ.
Is there a federal solar tax credit in California?
The 30% federal tax credit ended for homeowner purchases after December 31, 2025. Check your state, utility and local programs separately.
Where does the California sun figure come from?
1,677 kWh per kW per year and 4.05 winter peak sun hours come from NREL PVWatts v8 runs for California's largest city, compiled by TheGreenWatt (as of 2026-11). Real yield varies across the state.
Is my bill uploaded?
No. Your bill is read in your browser and never uploaded.