What solar costs in Washington
Berkeley Lab does not have enough reported installations in Washington to publish a reliable local price, so the figures below use the national median. Treat them as a starting point, not a quote.
The numbers
High electricity prices make solar pay faster, so a red figure in the third box is good news for a solar buyer and bad news every other month of the year.
Holding a quote above $30,000? Installers in Washington price the same system very differently. Two more bids is the cheapest way to find out where yours sits.
Plain outbound links. We take no phone numbers and sell no leads: you give your details to the company that will actually call you, not to us.
What the roof makes month by month in Seattle
A 4.8 to 1 swing across the year, which is steep. A system sized to cover your annual usage will run a large surplus in summer and leave you buying most of your winter power from the grid. Whether that works depends entirely on whether your utility banks the summer surplus for you.
Figures are for an 8 kW array at 20 degrees facing south, modelled from NSRDB radiation data at Seattle.
What different sizes cost in Washington
| Size | Panels | Price | Output | Year one saving | Payback |
|---|---|---|---|---|---|
| 4 kW | 10 | $15,000 | 4,344 kWh | $639 | 19.5 years |
| 5 kW | 13 | $18,750 | 5,430 kWh | $799 | 19.5 years |
| 6 kW | 15 | $22,500 | 6,516 kWh | $959 | 19.5 years |
| 7 kW | 18 | $26,250 | 7,602 kWh | $1,118 | 19.5 years |
| 8 kWtypical | 20 | $30,000 | 8,688 kWh | $1,278 | 19.5 years |
| 10 kW | 25 | $37,500 | 10,860 kWh | $1,598 | 19.5 years |
| 12 kW | 30 | $45,000 | 13,032 kWh | $1,917 | 19.5 years |
| 15 kW | 38 | $56,250 | 16,290 kWh | $2,396 | 19.5 years |
| 20 kW | 50 | $75,000 | 21,720 kWh | $3,195 | 19.5 years |
Payback is the same at every size because this table holds the price per watt flat at the national median of $3.75: price and output both grow in step with the system, so their ratio does not change. Real quotes are not quite linear. Permitting, design and connection cost roughly the same on any roof, so a small system usually costs more per watt and a large one less, and pays back correspondingly later or sooner than shown.
Washington has too few reported installations for a local median, so the price is the national median of what households paid on host-owned systems installed in 2024-2025, compiled by Berkeley Lab. Local quotes can sit well above or below it.
7 programmes in Washington
The 30% federal credit ended for installations completed after 31 December 2025. These state, utility and local programmes are unaffected by that, and are now the only thing that reduces the price.
| Programme | Type | Run by | Reach | Updated |
|---|---|---|---|---|
| Energy Efficiency and Solar Grants | Grant Program | State | statewide | September 27, 2023 |
| Interconnection Standards | Interconnection | State | statewide | May 31, 2024 |
| Net Metering | Net Metering | State | statewide | March 31, 2026 |
| Renewable Energy Sales and Use Tax Exemption | Sales Tax Incentive | State | statewide | January 12, 2026 |
| Grays Harbor PUD - Net Metering | Net Metering | Utility | partial | March 31, 2026 |
| Richland Energy Services - Residential Energy Conservation & Solar Loan Program | Loan Program | Utility | partial | July 14, 2025 |
| Solar Easements & Rights Laws | Solar/Wind Access Policy | State | partial | January 16, 2026 |
Programme index from DSIRE, N.C. Clean Energy Technology Center, NC State University, licensed CC BY-SA 4.0. “Partial” means it reaches only some utilities or counties. A listed programme can still be closed or out of budget, so check its own page before counting on it.
How Washington ranks
Solar in Washington, answered
How much do solar panels cost in Washington?
An 8 kW system in Washington, roughly 20 panels, costs about $30,000 before incentives. That is based on $3.75 per watt, the national median from Lawrence Berkeley National Laboratory for 2024-2025, because too few Washington installations are reported to publish a local figure. There is no longer a federal tax credit to subtract from that figure.
Is there still a 30% solar tax credit in Washington?
No. The federal Residential Clean Energy Credit under Internal Revenue Code section 25D was terminated by the One Big Beautiful Bill Act for expenditures made after 31 December 2025, and it did not step down first. A Washington homeowner buying a system with cash or a loan today receives no federal tax credit. Under a lease or power purchase agreement the credit survives as section 48E but belongs to the company that owns the equipment, not to the household. Washington still has 7 state, utility or local programmes covering rooftop solar.
How long do solar panels take to pay for themselves in Washington?
About 19.5 years in Washington. An 8 kW system costs roughly $30,000 and saves about $1,278 in its first year at the state's average residential rate of 14.71 cents per kilowatt-hour (EIA, July 2026). That calculation includes no federal tax credit, because the residential credit ended after 31 December 2025.
How much electricity does a solar panel produce in Washington?
Each kilowatt of panels in Washington produces about 1,086 kilowatt-hours a year, modelled at Seattle facing south at a 20 degree tilt using NSRDB radiation data. An 8 kW system therefore makes roughly 8,688 kilowatt-hours a year. The national average is about 1,332 kilowatt-hours per kilowatt installed.
Is solar worth it in Washington?
It depends less on sunshine than on your electricity price. In Washington power costs 14.71 cents per kilowatt-hour (EIA, July 2026), which makes an 8 kW system pay for itself in about 19.5 years and clear roughly $10,870 over 25 years. Solar from your own roof works out at 14.7 cents per kilowatt-hour over its life, against 14.71 cents from the utility.
How many solar panels do I need in Washington?
A typical Washington installation is about 20 panels, which is 8 kW at the 400 watt module that is now standard and needs roughly 440 square feet of roof. To size it to your own use, divide your annual kilowatt-hours by 1,086, which is what each kilowatt of panels produces in Washington each year.
Do solar panels work in winter in Washington?
Yes, but output falls sharply. In Seattle a kilowatt of panels makes about 150 kilowatt-hours in Jul and about 31 in Dec, a swing of 4.8 to 1 across the year. A system sized to cover your annual consumption will therefore run a surplus in summer and leave you buying power in winter, so how your utility settles that difference matters as much as the size of the array.
Three competing quotes beat any amount of comparing panel brands
Sales cost and margin are over a third of an installed price in Washington, and they are the part that competition removes. A single quote from whoever reached you first is how people end up in the top quarter of what their neighbours paid.
Plain outbound links. We take no phone numbers and sell no leads: you give your details to the company that will actually call you, not to us.
Prices and rules change. We will tell you when they do
Berkeley Lab publishes installed prices once a year, the EIA updates electricity rates every month, and Congress changed the tax treatment of all of this in 2025. One email when something on this site actually changes, and nothing else.
Email address only. No phone field, no passing you to installers, unsubscribe in one click.