What would a plug-in solar kit save you?

Pick your state, then change anything that doesn’t match your situation. Every assumption is printed next to the result. The link in your address bar saves your inputs, so you can send it to someone.

No email neededYour state’s average rateOutput modeled for a vertical panel

StateYour electricity rate (¢ per kWh)Prefilled with California’s average (33.05¢, EIA, 2025-07 to 2026-06). Your bill shows your real rate.

Kit size

Which way the panel faces

Shade

Share of the output you use (%)Power you don’t use at the moment it’s made goes back to the grid, and may earn you nothing. A battery raises this number.Kit price ($)The default is a round number, not a quote. Enter your kit’s price.

Payback

6.7

years at 33.05¢/kWh

Yearly output: 852 kWh
Yearly savings: $225
10-year net: +$753

Assumptions

Output model: PVGIS 5.3, European Commission Joint Research Centre, ERA5 weather data. Panel mounted vertically, 14% system losses, modeled at Los Angeles
Shade: Our estimate, not a measurement: some shade ×0.8, heavy ×0.55
Rate: Held flat for 10 years. Rising rates shorten payback.
Not counted: Panel wear over time, tax credits, installation, battery losses