Home Solar Savings Calculator

For most US homeowners with a south- or west-facing roof and an electric bill above $100/month, solar pays back in 8 to 14 years and produces free electricity for a decade or more after that. Since the federal residential tax credit ended after 2025, the biggest variables left are your utility rate and your peak sun hours.

Homes in high-rate states like California, Massachusetts, or Hawaii see the fastest payback, often under 8 years and sometimes near 5. In low-rate, low-sun states like Washington, payback can stretch past 16 years. Solar still saves money there, just more slowly.

Not for new installations. The 30% Residential Clean Energy Credit (Section 25D) was terminated by the One Big Beautiful Bill Act for systems whose installation was completed after December 31, 2025, with no step-down or transition period. This calculator therefore applies no federal credit.

Leased and third-party-owned systems can still carry a separate commercial credit (Section 48E) through 2027, but the leasing company claims it, not you. Some lessors pass part of it through as a lower monthly payment. State and utility incentives still exist independently of the federal credit; check the DSIRE database for your area.

Cash purchase gives the highest lifetime savings and shortest payback. Solar loans add 1 to 3 years to payback depending on the rate, but total 25-year savings stay close to cash if rates are reasonable.

Leases and PPAs require no upfront cost, and since the homeowner credit ended in 2025 they are now the only route to federal credit value: the leasing company claims the 48E commercial credit and may pass part of it through as lower payments. Even so, total savings over 25 years are typically 40 to 60 percent lower than owning.

Net metering lets your utility credit you for excess solar power you export to the grid. This calculator assumes a 1:1 credit: every kWh you send back offsets a kWh you later draw. That's still standard in much of the US.

Some states have moved to lower export rates. California's NEM 3.0 credits exports at roughly 25% of the retail rate, which can cut bill savings 20 to 40 percent for typical homes without batteries. Check your utility's current net-metering policy before signing a quote.

The math is standard solar engineering: annual usage from your bill, system size from NREL peak sun hours, and a 0.8 derate factor for real-world losses (panel temperature, inverter, wiring). Cost assumes $2.50 to $3.25 per installed watt, the 2026 US average for residential systems.

Actual quotes vary by installer, roof complexity, equipment brand, and local incentives that aren't modeled here (state rebates, SREC markets, utility-specific programs). Use this calculator to size up the opportunity, then get 2 to 3 quotes before signing anything.

Modern monocrystalline panels carry 25-year production warranties and typically still generate at least 85% of their rated output at year 25. The cells themselves often keep producing usable power past 30 years.

The inverter is the part most likely to need replacement during the system's life; most last 10 to 15 years. Budget $1,500 to $3,000 for one inverter replacement. Microinverters and hybrid inverters carry longer warranties (20 to 25 years) but cost more up front.