Solar Power

• A residential solar electric system installed in an unshaded area typically generates about 1,000 kilowatt-hours (kWh) per year for each kW installed.
• Currently in Seattle, the average residential solar electric system size is 8kW. This represents an investment of about $24,000 before incentives or taxes.
• 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. If you install a net meter and generate more electricity than you consume, City Light will credit your electric bill for every kWh of electricity sent back to the power grid. Excess generation occurs when a solar energy system generates more kWh of electricity than a home consumes. This is measured in real-time by a City Light billing meter.

Net Metering

If your solar system is up to 100 kW, our Net Metering program provides kWh credits on your bill for the energy you produce. These credits are valued at your retail rate of electricity. Any solar energy you generate that isn't immediately needed by your home goes back onto City Light's grid and is added to your account's net meter kWh credit balance, lowering your future bills.

Find your retail rate.

See an example of a Solar Bill.

Review and submit a Level 1 Interconnection Agreement.

Meter Aggregation

You 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.

Solar may be a great option if you:

• Own your home 
• 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. 

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. Apply for interconnection with City Light. You will need to submit a Level 1 Interconnection Agreement, a Solar One Line (example), and a Production Meter Wiring Diagram. If you are planning an installation in a network area, your installation has battery backup, or your installation is larger than 10 kW, your application will be reviewed by our Network 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.
4. 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.
5. Obtain permits for your system through your local permitting jurisdiction. In Seattle, contact the Department of Construction and Inspections.
6. Claim your renewable energy tax credit on your next federal tax return. Review system qualifications and credit amounts.