How much electricity do solar panels produce in Seattle, Washington?

About 1,115 kWh a year for each kW of panels, for a roof-mounted, south-facing array at a 30° tilt with 14% system losses (PVWatts). A 9.7 kW system would make about 10,788 kWh in its first year. Shade, a different roof angle or an east or west-facing roof will change this.

How much could solar panels save in Seattle, Washington?

At Washington’s average residential price of 14.42¢ per kWh, a 9.7 kW system sized for an average US home would save about $1,556 in its first year and $53,034 over 25 years. That assumes the home uses all the power the panels make, electricity prices rise 3% a year and panel output falls 0.5% a year. Power sent to the grid is counted at zero. At the US average price of 18.19¢, the first-year figure would be $1,962.

How long do solar panels take to pay back in Seattle, Washington?

It depends on the installed price on your quote, which varies by installer and system, and we do not have a verified US average to use. Enter your quote in the calculator on this page: Seattle’s solar output and Washington’s electricity price are already filled in. Every $0.10 per watt adds about $970 to the price of a 9.7 kW system.

What do homes in Seattle, Washington pay for electricity?

Washington’s average residential price for January to August 2026 was 14.42¢ per kWh, against 18.19¢ for the US as a whole (EIA Electric Power Monthly, Table 5.6.B). Your own rate depends on your utility and plan, so use the figure from your bill in the calculator if you can.

How does Seattle compare with nearby cities?

Of the 5 nearest cities we cover, San Jose (714 miles away) gets the most sun at 1,653 kWh per kW, and Portland (145 miles away) the least at 1,144 kWh. Seattle gets 1,115 kWh, less than any of them. Within Washington, it ranks 7th of the 13 cities we cover.

Where do these figures come from?

Solar output is from the PVWatts V8 tool for Seattle’s coordinates in the Census Bureau Gazetteer, checked on 2026-11-11. The electricity price is the EIA residential average for Washington for January to August 2026, and household use is the EIA average for US homes. Each figure is listed with its source link at the bottom of this page.

Solar panels in Seattle, Washington: output, savings and payback

Solar panels in Seattle produce about 1,115 kWh a year for each kW installed, 26% less than the average of the 400 US cities in our data (1,517 kWh). Among the 13 Washington cities we cover, it ranks 7th of 13 for solar output, against an average there of 1,150 kWh.

Washington’s average residential electricity price for January to August 2026 was 14.42¢ per kWh, 3.77¢ below the US average of 18.19¢, according to the Energy Information Administration.

For a home using the US average of 899 kWh a month, a 9.7 kW system would cover a year’s use and save about $1,556 in its first year, or $53,034 over 25 years. With the average sunshine of the 400 US cities in our data, the same home would need a 7.1 kW system. Because Seattle gets less sun, it needs 36% more capacity to cover the same use, so at any price per watt the system costs 36% more and pays for itself later.

There is no verified US installed-price figure yet, so add the price per watt from your installer’s quote in the calculator below to see the payback period for Seattle.

A typical home in Seattle

System size: 9.7 kW; Sized to cover 10,788 kWh a year
First-year generation: 10,788 kWh
First-year savings: $1,556; At 14.42¢ per kWh
Savings over 25 years: $53,034; Prices rising 3% a year
Payback: Needs your quote; No verified US installed price yet: enter yours below

Assumes all the electricity the panels make is used at home, up to the home’s yearly use, and that panel output falls 0.5% a year. Power sent to the grid is counted at zero.

How Seattle compares

Seattle compared with the Washington and US averages
	Seattle	Washington average	US average
Solar output, kWh per kW a year	1,115	1,150	1,517
Electricity price per kWh	14.42¢	14.42¢	18.19¢
System size for a typical home	9.7 kW	9.4 kW	7.1 kW
First-year savings	$1,556	$1,556	$1,962

Averages are of the 13 places in Washington and the 400 US cities in our data, unweighted. The US column uses the US average price as well as the average sunshine.

Your home in Seattle

All amounts in US dollars.

Your home

Nearest city

Sets how much electricity each kW of panels makes in a year at your location.

Electricity use

kWh per month

Check your utility bill: most show monthly kWh. Average your last 12 months if you can.

Electricity price

cents per kWh

Starts at the Washington residential average for January to August 2026. Your bill shows your own rate.

Solar system

System size

Leave blank to size the panels to cover your yearly use, or enter the size on your quote.

Installed price

Price per wattTotal quoted price

Price per watt

$per W

Enter the price from your installer quote to see cost, payback and return. Your quote divided by the system size in watts (for example, a 6 kW system is 6,000 W).

Assumptions you can change

Panel output loss

% per year

Starts at 0.5%, the median of nearly 2,000 reported rates in an NREL review.

Electricity price change

% per year

A scenario, not a forecast. Try 0% and 5% to see how much it matters.

Used directly at home

Share of the panels’ output your home uses as it is made. 100% assumes all of it offsets power you would otherwise buy, up to your annual use.

Add a home battery

A battery only adds savings when you use less than 100% of your solar power directly. Lower “Used directly at home” under assumptions to model that.

Results

Payback period

Add your installer’s quoted price to see payback

First-year savings: $1,556
Savings over 25 years: $53,034
System size: 9.7 kW; Sized to cover your yearly use
First-year generation: 10,788 kWh

Cumulative savings over 25 yearsAdd your quoted price to compare against the cost.

Year-by-year table

Generation and savings for each of the 25 years
Year	Generation (kWh)	Price per kWh	Saved that year	Saved so far
1	10,788	$0.144	$1,556	$1,556
2	10,734	$0.149	$1,594	$3,150
3	10,680	$0.153	$1,634	$4,784
4	10,627	$0.158	$1,675	$6,458
5	10,574	$0.162	$1,716	$8,174
6	10,521	$0.167	$1,759	$9,933
7	10,468	$0.172	$1,802	$11,736
8	10,416	$0.177	$1,847	$13,583
9	10,364	$0.183	$1,893	$15,476
10	10,312	$0.188	$1,940	$17,416
11	10,261	$0.194	$1,988	$19,405
12	10,209	$0.200	$2,038	$21,443
13	10,158	$0.206	$2,088	$23,531
14	10,107	$0.212	$2,140	$25,671
15	10,057	$0.218	$2,194	$27,865
16	10,007	$0.225	$2,248	$30,113
17	9,957	$0.231	$2,304	$32,417
18	9,907	$0.238	$2,361	$34,778
19	9,857	$0.245	$2,420	$37,198
20	9,808	$0.253	$2,480	$39,678
21	9,759	$0.260	$2,542	$42,220
22	9,710	$0.268	$2,605	$44,824
23	9,662	$0.276	$2,670	$47,494
24	9,613	$0.285	$2,736	$50,230
25	9,565	$0.293	$2,804	$53,034

Savings count only electricity your home no longer buys. Power sent to the grid is valued at zero. Grid emissions data has not been verified yet, so no carbon figure is shown. See the methodology for every formula and source.

Nearby cities

City	Distance	kWh per kW a year	Price per kWh	System size	First-year savings
Portland, Oregon	145 miles	1,144	15.46¢	9.4 kW	$1,668
Sacramento, California	627 miles	1,645	32.58¢	6.6 kW	$3,515
Oakland, California	681 miles	1,615	32.58¢	6.7 kW	$3,515
San Francisco, California	684 miles	1,455	32.58¢	7.4 kW	$3,515
San Jose, California	714 miles	1,653	32.58¢	6.5 kW	$3,515

Solar panels in Seattle: questions

How much electricity do solar panels produce in Seattle, Washington?: About 1,115 kWh a year for each kW of panels, for a roof-mounted, south-facing array at a 30° tilt with 14% system losses (PVWatts). A 9.7 kW system would make about 10,788 kWh in its first year. Shade, a different roof angle or an east or west-facing roof will change this.
How much could solar panels save in Seattle, Washington?: At Washington’s average residential price of 14.42¢ per kWh, a 9.7 kW system sized for an average US home would save about $1,556 in its first year and $53,034 over 25 years. That assumes the home uses all the power the panels make, electricity prices rise 3% a year and panel output falls 0.5% a year. Power sent to the grid is counted at zero. At the US average price of 18.19¢, the first-year figure would be $1,962.
How long do solar panels take to pay back in Seattle, Washington?: It depends on the installed price on your quote, which varies by installer and system, and we do not have a verified US average to use. Enter your quote in the calculator on this page: Seattle’s solar output and Washington’s electricity price are already filled in. Every $0.10 per watt adds about $970 to the price of a 9.7 kW system.
What do homes in Seattle, Washington pay for electricity?: Washington’s average residential price for January to August 2026 was 14.42¢ per kWh, against 18.19¢ for the US as a whole (EIA Electric Power Monthly, Table 5.6.B). Your own rate depends on your utility and plan, so use the figure from your bill in the calculator if you can.
How does Seattle compare with nearby cities?: Of the 5 nearest cities we cover, San Jose (714 miles away) gets the most sun at 1,653 kWh per kW, and Portland (145 miles away) the least at 1,144 kWh. Seattle gets 1,115 kWh, less than any of them. Within Washington, it ranks 7th of the 13 cities we cover.
Where do these figures come from?: Solar output is from the PVWatts V8 tool for Seattle’s coordinates in the Census Bureau Gazetteer, checked on 2026-11-11. The electricity price is the EIA residential average for Washington for January to August 2026, and household use is the EIA average for US homes. Each figure is listed with its source link at the bottom of this page.

Sources for this page

Solar output for Seattle: developer.nlr.gov (checked 2026-11-11)PVWatts V8.5.0 outputs.ac_annual for a 1 kW system. Weather data: 241108.csv, station at 47.61000061035156, -122.3399963378906 (1,351 m away).
Washington electricity price: www.eia.gov (checked 2026-11-11)Washington, residential sector, year-to-date through August 2026. Published as 14.42 cents per kilowatthour.
US average price: www.eia.gov (checked 2026-11-11)U.S. Total, residential sector, year-to-date through August 2026. Published as 18.19 cents per kilowatthour.
Typical household use: www.eia.gov (checked 2026-11-10)Average annual electricity sold to a U.S. residential utility customer in 2022: 10,791 kWh ("an average of about 899 kWh per month").
Panel output loss: docs.nlr.gov (checked 2026-11-10)Median of nearly 2,000 reported degradation rates: "a median value of 0.5%/year" (average 0.8%/year).
Location: www2.census.gov (checked 2026-11-10)Census Gazetteer INTPTLAT/INTPTLONG (internal point) for GEOID 5363000, "Seattle city".

Methods and every other figure are on the methodology page.