What the sun is worth on your roof

Drag the slider to your average monthly bill. Every number below updates instantly, and every assumption behind it is listed at the bottom — nothing hidden.

How this estimate is built: Uses 445 W premium solar panels priced at $2.50/W, with the design rounded up to complete panels. The current summer model uses a $0.44/kWh weighted PG&E import rate, values direct daytime solar at $0.40/kWh, and values home battery energy delivered during the peak window at $0.52/kWh. It also includes a modeled $24/month fixed-charge floor, Bay Area production of about 1,500 kWh per kW per year, 6.6% annual utility-rate growth (PG&E’s residential average rate rose 39% from January 2021 to March 2026, per the CPUC Public Advocates Office), and 0.5% annual panel degradation. Under California Net Billing, exported solar is modeled at $0.06/kWh. Solar-only assumes about 35% of production is used instantly in the home. Adding one 13.5 kWh home battery increases estimated home use to about 80% after round-trip losses and adds $12,150 to the project ($900/kWh). This is a transparent planning estimate, not a quote or guarantee. Actual results depend on interval usage, rate plan, season, roof, shading, equipment, financing, battery operation, incentives, and future utility rates.