Washington solar panels guide 2025
Updated April 14, 2023Washington State has long been a place that supports renewable energy. So, it's no surprise that the beautiful state offers some pretty solid incentives for installing solar panels. With a state-mandated net metering policy, a 30% federal tax credit, and tax exemptions from the solar panels and the installation, going solar has the potential for significant savings in Washington.
We know it doesn't rain all the time here. Still, Washington, unfortunately, is one of the least sunny states in the country, meaning solar panels won't generate as much energy as most other parts of the U.S. No need to fret – Washington's incentives still make solar panels a worthy investment, especially if you're looking for ways to be environmentally friendly.
On this page:
Solar power prices, savings and payback in your part of Washington
The average cost for an installed residential solar system in Washington is currently $11,647 after claiming the 30% federal solar tax credit. This is $2.77 per watt. However, there is some variance in solar prices in different parts of the state. The graph below shows the average cost of installed solar systems in your part of the state.
Showing data for:
Prices based on a 6.8kW system, after 30% federal tax credit
Net profit (savings less system cost)
$49,300-$60,256
Payback period
5.6-6.9 years
Recommended size for the selected utility bill
6.8kW
Solar panel cost calculator
Cash flow graph based on cash purchase of a 6.8kW system
Are solar panels worth it in Washington
Solar panels have fallen in price by more than 80% in the last ten years. In 2022 they also remain subsidized by the 30% federal tax credit and the net metering law, making them an excellent investment. They offer a return well above the long term average return from both the share market and also property investment.
Another way to look at this question is the levelized amount you will pay for each kWh of power you will use over the next 25 years with and without solar panels. As you can see below the savings are significant.
Levelized cost of solar energy
?
Levelized cost per kWh is the cost of the solar system divided by the total number of kWh produced by a solar system over it’s lifetime
7¢ /kWh
If you don't get solar
21¢ /kWh
(forecast avg Washington electric rates over the next 25 years)
WA solar panel cost calculator
Washington solar incentives & tax credits
Federal solar tax credit
The most significant incentive to install solar panels for homes and businesses is the federal solar tax credit, which currently sits at 30% of the total solar panel installation costs. This percentage will remain the same until the end of 2032. Because home and business owners want the highest incentive possible, now, more than ever is the time to go solar in Washington.
Net metering
Washington has a state-mandated net metering policy that requires utilities to compensate customers when their solar system produces more electricity than they use. Your utility will credit you for any excess solar you generate at the company’s retail electric rate.
However, on March 31st of each calendar year, any remaining excess credits will be sent back to the utility companies without payment. They do not roll over to the following year.
Sales and use tax exemption
Washington offers sales and use tax exemption when you install solar panels on your home or business. When you have any type of solar machinery up to 100 kW installed on your roof, the state will not tax you on the material or the installation.
This exemption applies to customers who buy panels or other solar equipment between July 2019 and December 2029.
Table 2: Available incentive programs
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Eligibility: Federal incentive
Type: Personal Tax Credit
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Eligibility: State incentive
Type: Sales Tax Incentive
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Best unit price
$320.00 ($0.96 per watt)
Best system price
Installed 5.0kW system
$12,721.85
($2.53 p/w)
LG335N1K-V5 overview
Rated power
335 watts
Efficiency
19.6
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
KR
Best unit price
$562.50 ($1.50 per watt)
Best system price
Installed 4.9kW system
$12,120.18
($2.49 p/w)
LG375A1C-V5 overview
Rated power
375 watts
Efficiency
21.7
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
KR
Best unit price
$430.00 ($1.15 per watt)
Best system price
Installed 4.9kW system
$12,919.30
($2.65 p/w)
LG375Q1C-V5 overview
Rated power
375 watts
Efficiency
21.7
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
KR
Best unit price
$473.34 ($1.30 per watt)
Best system price
Installed 5.1kW system
$13,231.07
($2.59 p/w)
LG365Q1K-V5 overview
Rated power
365 watts
Efficiency
21.1
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
KR
Best unit price
$432.00 ($1.20 per watt)
Best system price
Installed 5.0kW system
$13,276.66
($2.63 p/w)
LG360Q1K-V5 overview
Rated power
360 watts
Efficiency
20.8
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
US
Best unit price
$530.85 ($1.50 per watt)
Best system price
Installed 5.0kW system
$12,386.87
($2.49 p/w)
LG355Q1K-V5 overview
Rated power
355 watts
Efficiency
20.6
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
US
Best unit price
$495.00 ($1.38 per watt)
Best system price
Installed 5.0kW system
$13,091.06
($2.60 p/w)
LG360Q1C-V5 overview
Rated power
360 watts
Efficiency
20.8
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
US
Best unit price
$407.97 ($1.10 per watt)
Best system price
Installed 5.2kW system
$13,159.30
($2.54 p/w)
LG370Q1C-V5 overview
Rated power
370 watts
Efficiency
21.4
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
US
Best unit price
$323.39 ($0.97 per watt)
Best system price
Installed 5.0kW system
$12,691.01
($2.53 p/w)
LG335N1C-V5 overview
Rated power
335 watts
Efficiency
19.6
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
US
Best unit price
$338.19 ($0.99 per watt)
Best system price
Installed 5.1kW system
$0.00
($0.00 p/w)
LG340N1C-V5 overview
Rated power
340 watts
Efficiency
19.8
Number of Cells
60
Cell type
Monocrystalline/N-type
Manufactured
US
Best unit price
$600.00 ($1.83 per watt)
Best system price
Installed 4.9kW system
$12,808.41
($2.61 p/w)
SPR-E20-327-COM overview
Rated power
327 watts
Efficiency
20.4
Number of Cells
96
Cell type
Monocrystalline
Manufactured
US
Best unit price
$800.00 ($2.22 per watt)
Best system price
Installed 5.0kW system
$13,201.67
($2.62 p/w)
SPR-X22-360 overview
Rated power
360 watts
Efficiency
22.2
Number of Cells
96
Cell type
Monocrystalline
Manufactured
US
Best unit price
$620.00 ($1.90 per watt)
Best system price
Installed 4.9kW system
$13,703.10
($2.79 p/w)
SPR-E20-327-D-AC overview
Rated power
327 watts
Efficiency
20.4
Number of Cells
96
Cell type
Monocrystalline
Manufactured
US
Best unit price
$620.00 ($1.90 per watt)
Best system price
Installed 4.9kW system
$13,610.59
($2.77 p/w)
SPR-E20-327 overview
Rated power
327 watts
Efficiency
20.4
Number of Cells
96
Cell type
Monocrystalline
Manufactured
US
Best unit price
$181.00 ($0.60 per watt)
Best system price
Installed 5.1kW system
$11,003.04
($2.16 p/w)
CS6K-300MS overview
Rated power
300 watts
Efficiency
18.33
Number of Cells
60
Cell type
Monocrystalline
Manufactured
CA
Best unit price
$196.11 ($0.65 per watt)
Best system price
Installed 5.1kW system
$9,948.02
($1.95 p/w)
LR6-60-HPB-300M overview
Rated power
300 watts
Efficiency
18.1
Number of Cells
120
Cell type
Mono PERC
Manufactured
CN
Best unit price
$172.00 ($0.56 per watt)
Best system price
Installed 4.9kW system
$9,568.53
($1.96 p/w)
LR6-60-HPB-305M overview
Rated power
305 watts
Efficiency
18.4
Number of Cells
120
Cell type
Mono PERC
Manufactured
CN
Best unit price
$165.00 ($0.53 per watt)
Best system price
Installed 5.0kW system
$9,761.72
($1.97 p/w)
LR6-60-HPB-310M overview
Rated power
310 watts
Efficiency
18.7
Number of Cells
120
Cell type
Mono PERC
Manufactured
CN
Best unit price
$228.00 ($0.60 per watt)
Best system price
Installed 4.9kW system
$9,579.65
($1.94 p/w)
LR4-60HPH-380M overview
Rated power
380 watts
Efficiency
20.9
Number of Cells
120
Cell type
Mono PERC
Manufactured
CN
Best unit price
$234.00 ($0.60 per watt)
Best system price
Installed 5.1kW system
$10,126.74
($2.00 p/w)
LR6-72HBD-390M overview
Rated power
390 watts
Efficiency
19.4
Number of Cells
144
Cell type
Mono PERC
Manufactured
CN
Average cost of solar panel installation in Washington by system size
System size* |
Cash purchase(After tax credit) |
Financed purchase(After tax credit) |
|---|---|---|
| 4kW | $12,088 | $12,934 |
| 5kW | $14,550 | $15,569 |
| 6kW | $16,638 | $17,803 |
| 7kW | $19,243 | $20,590 |
| 8kW | $22,200 | $23,754 |
| 9kW | $24,084 | $25,770 |
| 10kW | $26,520 | $28,376 |
Best solar companies in the main cities of Washington
Home solar basics
Is it better to lease or buy solar panels in Washington
You will save most money by buying your solar system rather than leasing it. Read more about the pros and cons of leasing vs buying solar.
How long do solar panels last?
Minimum of 25 years but generally 30 or more
How do solar panels work on a home?
Solar panels power your house when they can but your home uses the utility company for power at other times. In 2025 "solar systems with battery storage" are becoming more popular. These are known as hybrid systems.
How do solar panels work?
Grid-tied solar system
A grid-tied system is the most common type of solar system. It has no solar battery for backup power and utilizes net metering to maximize savings. Solar panels are mounted on your roof then wired together, and the power generated flows into an inverter where direct current (DC) electricity is converted into alternating current (AC) electricity. This electricity is either used by your home or is exported to the utility grid.
Hybrid solar system
In hybrid solar systems, rooftop solar panels are connected to both a solar battery and the electric grid. The solar electricity generated by your panels that your home does not use is stored in the battery instead of being sent to the grid, which reduces your reliance on the utility while also providing backup power when needed. Battery storage is still expensive but you may be able to reduce costs by using state incentives.
Off-grid solar system
Off-grid solar systems are not connected to the grid at all, so all of your energy needs must be met by the sun. There is no utility to fall back on. The solar installation needs to power your home not only during the day, but after dark as well, so many solar panels and a large battery system are required. These systems are often expensive and don’t make sense for homes that have access to the grid.
Read more about types of home solar systems.
Do solar panels require regular maintenance?
No, but cleaning them can improve power generation if they are dirty.
Will residential solar power system cost fall in Washington in 2025?
Given this environment, and the effect of import tariffs placed on solar panels by the Trump administration during 2018, it is hard to see that solar power system prices in Washington will fall during 2025.
How much electricity do solar panel systems generate in Washington?
Depending on the location, solar panels will generate different amounts of electricity.
A solar system that is installed on a south-facing 34-degree pitch roof Washington will generate 1,330kWh of peak DC (direct current) capacity per year per 1kW in the Seattle area.
Enter your details into the solar panel calculator to see how your location, roof tilt, and roof direction impacts solar panel production.
What are the pros and cons of installing solar panels in Washington?
The advantage of installing solar panels in Washington is the state-mandated net metering law which is crucial to making solar a worthwhile investment. Couple that with the 30% federal tax credit, and you have great potential to save money.
The main disadvantage of installing solar panels in Washington is that Washington gets way less sunshine on average compared to many other states. Washington also has some of the lowest electricity rates in the U.S., so solar panels won't save as much money here.
Enter your details to calculate the cost and savings you are likely to get from installing solar panels for your home.
What you can learn from our state solar panel calculator
This solar calculator requires you to input your address, utility company, your average monthly power spend - it tells you:
- What size solar system do you need?
- Answers the question of How many solar panels do I need?
- How many square feet of roof space you need for solar panels
- Solar electricity production in annual kWh (kilowatt-hours) you can expect from your solar system in Washington
- The value of solar tax credits and other incentives you are entitled to based on the estimated size of system you need, your location and your utility provider.
- Likely cost based on an average of prices charged for solar systems of that size in the last year in Washington or
- The likely payback period on your solar panels and your investment return.
- Your total lifetime solar savings based on each of the major solar finance options, a cash purchase, a cash purchase funded with a HELOC (home equity line of credit) and a zero-down PPA or third party lease product.
If you want to see all of the above but also see live pricing, the three best solar deals available in your city and get binding quotes from each of these solar companies then use this Washington solar panels calculator. This calculator requires you to also input your name and contact details because most of our 200+ installer partners will only authorize the sharing of their live solar pricing where we have validated that you are a real homeowner with a home in their service area. We respect the privacy of your data and only share your contact details with the solar companies you ask us to get binding quotes from.
Note: Please keep in mind that the best source of up-to-date information on incentives are the solar installers who specialize in your area.
