How to use
- Use the system price after incentives you are sure you can claim. Do not subtract a credit you have not checked.
- Yearly kWh should come from the proposal, not from a neighbor's roof.
- Type the price you pay per kWh, including the supply charge if that is what solar offsets. Export rates are often lower.
- Degradation is a small yearly drop. Half a percent is a common planning guess, not a promise.
Solar ads sell a monthly payment. Payback is a different question: how many years of production, at your rate, cover the cash you spent. If the proposal assumes the utility rate rises 5% every year, this page will look slower, because it does not invent a rate hike.
Worked example. $14,000 after incentives, 9,000 kWh a year, $0.16 per kWh. Year one offsets $1,440. If production slipped 0.5% a year and the price stayed $0.16, the cash comes back in about 10 years. A loan with interest stretches that. Type the cash you pay, not the sticker before a dealer fee.
Net metering is the trap. If the utility pays $0.05 for exports and you use power at night, you do not offset 9,000 kWh at $0.16. Type a lower effective rate, or only the kWh you will use on site.
Shade, snow, and a west roof cut the kWh the salesperson averaged from a south roof. If the proposal has a shade report, use that kWh, not the national average.
This is not tax advice. Credits and rebates have rules. Read the incentive before you subtract it from the cost field.
FAQ
Is this a solar quote?
No. It is payback math from numbers you already have.
Should I assume electricity prices rise?
Only if you want a guess. This page keeps the price you type.
What kWh number do I use?
The yearly production on the proposal for your roof, not a generic watts-times-hours rule.
Does degradation matter?
A little each year. Over 25 years it is real. The loop includes the percent you type.
Do you store my address?
No. There is no address field.