Washington solar potential

Solar Savings Calculator

Estimate solar payback period and long-term savings in Washington using real solar production data.

Solar savings estimate

System inputs

Pre-filled with Washington solar data

A typical residential rooftop system ranges from about 5 to 10 kW.

Switch the unit to enter either a total project cost or a cost per watt.

Defaulted to the average rate in Washington. Edit it if your utility bill shows a different rate.

Results

Savings & payback

Annual savings

$628

Payback period

28.7 yrs

25-year net savings

-$2,294

Production breakdown

Annual production

5,141 kWh

Total install cost

$18,000

Production per kW

857 kWh

Rate used

12.2¢/kWh

How it works

The calculator multiplies your system size by the estimated annual production per kilowatt for your location to get total annual output in kWh, then values that output at your electricity rate to estimate annual savings.

Payback period is your total install cost divided by annual savings. 25-year net savings projects that same annual savings forward and subtracts the upfront cost — it does not account for panel degradation, rate changes, or maintenance.

The production estimate above reflects solar resource data for Washington. Actual output depends on roof angle, shading, panel efficiency, and local weather patterns.

Solar potential in Washington

As of June 2026, a solar system in Washington can be expected to produce roughly 857 kWh per kilowatt of installed capacity each year, based on solar resource data from NREL. Use the calculator above to estimate payback period and long-term savings for a specific system size and cost.

Check another state

Solar production varies by climate and latitude. Compare your state's potential against any other.