Costs, Incentives, and Installation Basics
Performance and Typical Costs:
A residential solar electric system installed in an unshaded site 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 7kW. This represents an investment of about $24,000 before incentives or taxes. Generally, the larger the system, the lower the cost per kW installed.
6 Steps to Solar Energy Installation
Step 1: Assess your Property and current electric service
Adding a solar system is considered a modification to your service and may require additional work to bring the existing equipment up to today’s code requirements. Beginning work without an assessment may result in additional cost and delays. To alleviate this, Seattle City Light can do a free, on-site assessment of your existing electric service to determine if it is in compliance with current codes. Locate your Electric Service Representative here or by calling the intake desk at 206-233-2777.
Step 2: Obtain bids and choose A solar contractor
We recommend obtaining a minimum of three (3) bids. There are many contractors to choose from, and while City Light does not endorse or refer contractors, Solar Installers of Washington maintains a list of possible qualified installers for your consideration.
Step 3: Complete these documents
Apply for interconnection by filling out an Application for Electric Service prior to system installation. As part of the application process, you will need to submit:
- Level 1 Interconnection Agreement (for arrays up to 100 kW) or Level 2-4 Interconnection Agreement (for arrays larger than 100 kW)
- Solar One Line (example)
- Production Meter Wiring Diagram
If you are planning an installation in any of the Seattle City Light Network Service Areas, 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. To determine if your project is located in a network area please download a network map.
Step 4: Obtain permits
Have your system permitted, installed and inspected by your local permitting jurisdiction. In Seattle, contact the Department of Construction and Inspections.
Step 5: Claim your tax credit
On your next federal income tax return, claim your renewable energy tax credit (review system qualifications and credit amounts here).
Step 6: Participate in City Light Programs
City Light compensates eligible customers on their utility bill when they provide excess solar generation to the grid. If your installed solar system is up to 100 kW, you will get kWh credits through the Net Metering program. If your installed system is over 100 kW and up to 2 MW, you will get cash credits through the Large Solar program. Certain high-performing buildings will receive net metering for solar installations up to 250 kW.