Plug-in solar savings calculator
Pick your state, size, and mounting. We estimate yearly output, dollar savings, and payback. Assumptions are listed below so you can sanity-check them.
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Most US kits are 400 to 1,200 W. State laws usually cap AC output at 1,200 W.
85%. Without net metering, power you don't use in the moment is given to the grid for free. Homes with daytime loads (fridge, Wi-Fi, home office) use most of it.
Pre-filled with your state's average residential rate. Check your bill for the real number.
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How this calculator works
- Output = panel watts × your state's typical annual kWh per kW (NREL PVWatts-style figures for a fixed south-facing tilt) × a mounting factor. Vertical balcony mounts produce roughly 30% less than a tilted array; east/west and shading cut further.
- Savings = output you self-consume × your electricity price. We default to 85% self-use because small kits rarely exceed a home's daytime baseline load.
- Payback = kit cost ÷ yearly savings. Lifetime savings assume 25 years, 0.5% annual panel degradation, and 3% annual price growth.
- CO₂ uses the US average grid intensity of about 0.37 kg per kWh.
These are planning estimates, not quotes. Real output depends on your exact orientation, shading, and weather.