How is my solar savings estimate calculated?+
Estimates scale from real 2026 market averages for your selected city: installed cost per watt, average system size relative to your monthly bill, and current utility rates. Solar-only savings are modeled at roughly 70% of solar-plus-battery savings under NEM 3.0, where exported power earns only $0.05–$0.08/kWh. No expired incentives are included — the federal 30% credit ended December 31, 2025.
Does the calculator include the federal solar tax credit?+
No, because it no longer exists for homeowners. The 30% residential credit (Section 25D) expired December 31, 2025. Estimates reflect full cash cost, minus battery rebates where you qualify (such as SDCP's up-to-$6,750 program for San Diego Community Power customers; CEA cities like Vista and Carlsbad don't qualify).
Why does adding a battery change my payback so much?+
Under NEM 3.0 in California, power you export earns $0.05–$0.08/kWh but peak grid power costs $0.55–$0.70/kWh. A battery shifts your solar to evening peak hours, capturing retail value. For San Diego Community Power customers (Encinitas, San Diego, Chula Vista and other SDCP cities — not CEA cities like Vista, Carlsbad, Oceanside, or San Marcos), SDCP battery rebates offset up to $6,750 of the battery's cost.