• A solar electric system installed in an unshaded area typically generates about 1,000 kilowatt-hours (kWh) per year for each kW installed.
• Generally, the larger the system, the lower the cost per kW installed.
• Other factors that can impact costs include design complexity, system configuration, equipment options, and contractor expertise.

All solar installations that connect to the City Light power grid are required to have an Interconnection Agreement. Find the proper agreement for your solar installation below.

City Light will credit your electric bill for solar energy you generate that isn't immediately needed by your property and is sent back onto the power grid. These power exports are measured in real-time by a City Light net billing meter and are compensated in accordance with either our Net Metering or Large Renewables program, depending on the size of your renewable energy system.

Net Metering

If your solar system is up to 100 kW AC, our Net Metering program provides kWh credits on your bill for the energy you send back onto City Light's grid. These credits are valued at your retail rate of electricity.

Find your retail rate.

Certain high-performing buildings may receive net metering for solar installations up to 250 - 500 kW when they meet the following criteria:

• Buildings within the City of Seattle that meet the terms of Seattle's Living Building Pilot (up to 250 kW)
• Buildings outside the City of Seattle that receive Living Building Challenge certification (up to 250 kW)
• Affordable housing performing under high energy efficiency standards as determined by City Light (up to 500 kW)

Meter Aggregation

Net Metering customers may also qualify for net meter aggregation, which allows you to share excess generation with one additional City Light billing meter that is under the same account name and located on the same or a contiguous parcel. Sharing excess generation can reduce utility bills on an account not supported by your solar energy system.

Apply for meter aggregation.

Large Renewables

If your solar system or other qualified renewable generator is over 100 kW AC and up to 5 MW you will receive credits through our large renewables program for excess generation at an export rate that varies by month. Export rates are highest during the summer months and range from $0.031 per kWh to $0.094 per kWh throughout the year.

The export rate represents the value of excess renewable generation to City Light and incentivizes generators sized to meet building demand. Your business will be compensated for excess generation sold to the grid, calculated each day. Credits appear on your next utility bill. For the latest export rate, see Seattle Municipal Code 21.49.083 Large Customer Renewable Generation Program.

1. Assess your property and current electric service to ensure existing equipment meets code requirements. Explore resources and requirements for adding or upgrading electrical service on your property.
2. Get bids and choose a solar contractor. While we do not recommend or endorse contractors, we do recommend at least 3 bids and reference checks. Here is a resource to help you find an installer: Washington Solar Energy Industries Association.
3. First, review our Distributed Energy Resources Interconnection Handbook. To apply for interconnection with City Light, complete an online application for electric service.
   • If you are the property owner, you will also be required to fill out an Interconnection Agreement appropriate to the size of your array. An Interconnection Agreement will be presented to Applicants during the application process.
4. After review and completion of the application, City LIght will send a Level 1-2 Interconnection Agreement for systems below 100 kW or a Level 3-4 Interconnection Agreement for systems above 100 kW for you to review and submit prior to construction. You will also need to submit a Solar One Line (example) and equipment data sheets along with the application. Note, our interconnection agreements are provided online for example only, City Light staff will provide you with the correct version based on your project.
   • If you are planning an installation in a network area, your application will be reviewed by our Network Engineering Department.
   • If your installation will not be in the network area and your installation has battery backup, or your installation is larger than 12 kW, your application will be reviewed by our Engineering Department, which can add additional time to the interconnection approval process.
   • Network installations may also require special equipment.
   • Review our interactive service area map to determine if your project is located in a network area (view the Find Your ESR tab) and find contact information for the assigned Electric Service Representative.
5. If you have multiple meters on your property or own two contiguous properties and are interested in net metering aggregation, submit a Meter Aggregation Application.
6. Obtain permits for your system through your local permitting jurisdiction. In Seattle, contact the Department of Construction & Inspections.
7. After your solar system has been constructed and is ready to operate, you must complete the Commissioning and Testing Form and submit it to City Light. This documentation confirms that your system has been installed in accordance with applicable standards and is operating safely.
8. Claim your renewable energy tax credit on your next federal tax return. Review system qualifications and credit amounts.

What is Community Solar?

The U.S. Department of Energy defines community solar as any solar project or purchasing program, within a geographic area, in which the benefits flow to multiple customers such as individuals, businesses, nonprofits, and other groups. In most cases, customers benefit from energy generated by solar panels at an off-site array.

Community solar customers typically subscribe to — or in some cases own — a portion of the energy generated by a solar array and receive an electric bill credit for electricity generated by their share of the community solar system. Community solar can be a great option for people who are unable to install solar panels on their roofs because they are renters, can’t afford solar, or because their roofs or electrical systems aren’t suited to solar.

Learn more about Community Solar from the U.S. Department of Energy.

City Light Community Solar Program

City Light is currently in the design phase of a new Community Solar program.

Other Related Programs

• Washington State University (WSU) Community Solar Expansion Program - City Light is a participating utility! WSU’s Energy Program administers a community solar incentive program providing $100 million in payments for the development of projects benefiting low-income individuals, low-income service providers, and qualifying tribal or public agencies for at least 10 years. Eligible administrators (those that can apply for funds) include: utility, nonprofit, tribal housing authority or other local housing authority. Eligible administrators must contact WSU at CSEP@energy.wsu.edu for a pre-certification application. Funds are limited, awarded on a first-come, first-served basis, and the program will close once all funds have been allocated or on June 30, 2036 (whichever comes first).
• U.S. Environmental Protection Agency (EPA) Solar for All - A grant to make solar energy accessible to income-qualified Washingtonians. Administered by the Washington State Department of Commerce and designed to fill critical gaps in current and historic solar programs.

The federal government offers several tax credits that may reduce the overall costs of clean energy projects. Signed into law on July 1, 2025, H.R.1 phases out those incentives. Below is a summary of the credits relevant to clean energy projects, specifically solar energy, and the phase-out date. The below dates are subject to further clarification from the IRS.

Clean Electricity Production and Investment Tax Credits

The Clean Electricity Production Credit (PTC) and Clean Electricity Investment Credit (ITC) are technology-neutral tax credits for wind and solar energy generation. Production and Investment tax credits, as authorized under IRC §45Y and §48E, may apply to certain qualified facilities listed under IRC §45(d). To receive credit under these sections, you must meet certain construction and in-service milestones within specified time periods. There are no strict project size eligibility requirements, but credits and requirements vary by project size and tax credit.

Disclaimer: This overview is informational only. City Light is providing this information to inform customers of changes to federal law related to clean energy credits. Also, this IRS guidance was published before the passage of H.R.1. Any IRS guidance is subject to further clarification from the IRS and Department of Treasury. Please do not rely on the information provided below in determining whether a tax credit may apply to a specific project or type of project. Instead, seek independent tax and legal advice from a qualified tax professional on how changes to federal law may affect you.

Solar may be a great option if you:

• Own your property
• Have a suitable, shade-free area for solar modules (such as roof space in good condition)
• Are interested in making a long-term investment to produce your own renewable energy and lower your electricity bill

Some other considerations:

• Your electricity usage: Do you want to produce part or all of your power? This will have an impact on the size of the system you choose.
• Your roof space and sun exposure: 1kW of solar typically requires about 80 square feet of unshaded roof space.
• Your budget: Will you finance or pay cash? What's your total budget? The upfront costs can be considerable, but financing can help. You will want to know this before choosing your system.

You are generating electricity when the sun is shining on your solar array! The energy your array harvests travels through your inverter to your breaker box where it immediately supplies electricity to your building. If your solar generation is not enough to meet your needs, your building draws electricity from City Light's grid. When your system is generating, your building uses your solar energy first and then electricity from City Light. If your solar generation is more than enough to meet your energy needs, the excess electricity you generate flows from your breaker box through your billing meter. City Light tracks it on your account as negative kWh usage (negative consumption) for the billing period.

Here is a visual representation of your solar energy system's relationship to your building and the utility grid:

City Light collects the information from your billing meter at the end of each billing period and calculates the difference between the electricity consumed (kWh delivered to customer by City Light) and the electricity generated (kWh received by City Light from customer) to determine the net kWh usage. If generation is greater than consumption (when the negative (-) kWh is greater than the positive (+) kWh on your bill), you will receive kWh credits or cash credits for the excess kWh based on the program in which you are participating.