Solar panel cost in Washington

The average cost for an installed residential solar system in Washington is currently $12,117 after claiming the 26% federal solar tax credit. This is $2.73 per watt.

Solar prices near you

Cost range of local prices


Net profit (savings less system cost)


Payback period

5.6-6.9 years

Recommended size for the selected utility bill


Chart 1: Distribution curve of WA residential solar cost 2020
SolarReviews average

Note: Prices after 26% Federal Solar Tax Credit

WA solar panel cost calculator

Cash flow graph based on cash purchase of a 5.4kW system

Washington solar power overview

Washington state has long been a place that supports renewable energy. In fact, Governor Jay Inslee signed a 100% clean energy bill in 2019. For a long time, that support for renewables extended to home solar, with a very good solar incentive program that allowed homeowners to install solar panels and get thousands of dollars back in payments. 

Sadly, that incentive program has ended, and now adding solar panels to your home in Washington has become far less financially advantageous. We know it doesn’t rain all the time here, but Washington is the lower 48’s least sunny state. That lack of sun, combined with ultra-low electricity prices because of the state’s huge installed base of hydro power means solar isn’t really a good financial decision in the Evergreen State.

If you’re committed to home solar energy for the environmental benefits, you should know that there are still incentives that can help make the green choice more affordable. Specifically, the 26% federal solar tax credit and Washington’s net metering law.

Are solar panels worth it in Washington

Solar panels have fallen in price by more than 80% in the last ten years. In 2020 they also remain subsidized by the 26% 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)

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. At the end of 2020, the amount of the credit will decrease from 26% to 22% of the cost of the solar installation. Because home and business owners want to get the largest incentive amount possible, solar panel installation companies will likely be flooded with new projects before year’s end. In order to maximize your savings potential, the best time to go solar in Washington is now.

Net metering

Washington’s net metering policy requires utilities to compensate customers when their solar system produces more electricity than they use. Customers will be reimbursed through on-bill credits that are equal to 1 kilowatt-hour (kWh) of energy. 

Let’s say your system produces 10 excess kWhs of electricity. You will then receive 10 kWh credits on your bill that will be used to offset the cost of the energy you use in the future.

Table 2: Available incentive programs
Eligibility: Federal incentive
Type: Personal Tax Credit
Eligibility: State incentive
Type: Sales Tax Incentive

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Top 10 solar panel brands installed in Washington in 2020

Average cost of solar panel installation in Washington by system size

System size*
Cash purchase

(After tax credit)

Financed purchase

(After tax credit)

4kW $11,924 $12,759
5kW $14,275 $15,274
6kW $16,374 $17,520
7kW $18,914 $20,238
8kW $22,000 $23,540
9kW $23,832 $25,500
10kW $26,210 $28,045

Find city information in Washington


Best solar companies in the main cities of Washington

Solar Companies in Seattle

Different types of solar companies

Solar company reviews

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 2020 "solar systems with battery storage" are becoming more popular. These are known as hybrid systems.

How do solar panels work?

Grid-tied solar system

Solar panels are mounted on your roof and wired together in groups called solar arrays. The power they generate flows into a solar inverter where the direct current (DC) electricity is converted into alternating current (AC) electricity that can be used by your home or exported to the electric grid.

Off-grid solar system

Off-grid solar power involves meeting all your energy needs from the power of the sun. There’s no utility to fall back on. This means the solar installation needs to power the home not just during the day, when the sun is shining, but after dark as well.

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 2020?

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 2020.

Can you buy DIY Solar Panel Kits and install them yourself in Washington?

Yes you can! In some cases, you can save $3,000 or more when you install solar yourself, even after receiving the federal tax credit. Despite the potential for savings, data from Lawrence Berkeley Labs shows that only about 3% of homeowners choose DIY solar. 

Reasons for this include:

  • The permitting and inspection process for the utility, the state, and municipalities can be quite complex.
  • The installation work is both dangerous and difficult, with electrical work having to be performed at heights.
  • Often times, solar electricity customers will be charged a premium for DIY installations, which can limit savings.
  • In some states, a solar system needs to be installed by a qualified solar contractor in order to take advantage of incentives. In Washington, a solar installer must hold an electrician’s license in order to be considered qualified. Utilities and incentive programs may have additional requirements.


SolarReviews does not recommend DIY solar installations unless you have suitable skills. However, for those who do, SolarReviews published a comparison table displaying solar panel kit prices from the top 10 leading solar kit websites in the US.

Buy DIY solar panel kits online

Prices don’t include installation, permits or inspections

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 key to making solar a worthwhile investment. Couple that with the federal tax credit and you have the potential for great savings.

The main disadvantage of installing solar panels for your home in Washington is that there is less overall sunshine in the state per year, on average. This means a solar system produces less here than it would in sunnier states, such as Arizona. Also, the cost of grid power is cheap in Washington so you get less money back for excess generation than you might in a state with higher electricity prices. 

Despite these, there are still ways to save on a solar system that make going solar in Washington an excellent choice.

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:

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.

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