Solar savings calculator
Depends on sun and shade. Ask the installer. 1,400 is an example.
Twelve months of bills.
Power used as it is made. 50 is an example.
Use the price from your bill if you know it.
Your utility's export rate. It may be lower than the retail price.
An example. Use the quote.
Estimated savings
Every input here is an example, including the production per kW, the share used on site and the 2 percent yearly price rise. It leaves out financing, taxes, battery storage and equipment replacement. Ask installers for their production estimate and the assumptions behind it.
How the estimate is built
- Production equals system size times yearly output per kW, reduced each year by the drop in output you enter.
- The share used on site is valued at your retail price. The rest goes to the grid and is valued at your export credit.
- The retail and export prices rise each year by the rate you enter.
- Savings add up over the years you choose, and payback is the point at which they reach the net cost.
Why the credit for exports matters
How much the export credit and on-site use change the answer
| Share used on site | Export credit 17.2 cents | Export credit 10.3 cents | Export credit 5.2 cents |
|---|---|---|---|
| 30 percent | $1,448 | $1,042 | $738 |
| 50 percent | $1,448 | $1,158 | $941 |
| 70 percent | $1,448 | $1,274 | $1,144 |
Source: 6 kW, 1,400 kWh per kW, 10,492 kWh of yearly use, retail 17.23 cents from EIA Form EIA-861. The export credits shown are 100, 60 and 30 percent of that retail price, as examples of different rules.
Where to get a production estimate
Yearly output per kW depends on sun, tilt, direction and shade. Installers give an estimate with their assumptions, and the National Renewable Energy Laboratory's PVWatts calculator gives an independent one for an address. Use both, and ask the installer to explain any gap.
Incentives and the net cost
The net cost should be what you pay after any rebates. The federal homeowner credit ended for 2026 installs, and state and utility offers vary. See solar incentives and federal tax credits for the dates and sources.
What the estimate leaves out
- Financing costs, taxes and the value of a battery.
- Inverter replacement and other maintenance.
- Changes to your utility's rules, which can lower or raise the value of exported power.
- The effect on a home's sale price, which varies.
Frequently asked questions
How do I estimate solar savings?
Multiply the system’s yearly kWh by what each kWh is worth, using your retail price for power used on site and your export credit for the rest. The calculator does this and adds payback.
What is a simple payback?
The number of years of savings it takes to equal the net cost of the system, with no interest or financing included.
Why does the export credit matter?
Because power sent to the grid may be credited at a lower rate than power you use. The lower the credit, the more it pays to use solar power in the home.
Does this calculator store my numbers?
No. It runs in your browser and nothing you enter is sent to our servers.