Solar Panels Cost $15k-$25k in Walla Walla County, WA | August, 2025

Residential customers of Clark Public Utilities may be eligible for special loans to fund new solar energy systems and components. The maximum available principal per loan is $30,000 at 3.5% APR. The principal determines both repayment period duration and the applicable fees and conditions. Additional information is available from the CPU website.

The Grays Harbor Public Utility District operates a unique net metering program. Credits for net excess generation are awarded at the end of each year and amount to half of the normal retail price. While the Grays Harbor program technically does not follow the letter of the state's net metering laws, customers may earn additional benefits and have a greater incentive to adopt renewable energy. Additional information is available through the utility website.

Seattle's zoning laws and local ordinances contain special provisions and accommodations for solar energy within city limits. All new solar projects are required to obtain electrical permits, but may not need building permits if the total system weight is less than 1,000 pounds or the system does not require alterations/stand-alone structure of more than $4,000. Setback requirements prohibit systems from being located in a front yard. However, solar panels may extend up to four feet from the normal height limit for the zone. A central guide is available from the city website detailing all applicable regulations and process flows.

The Sustainable Energy Program/Trust is a division of the Washington State Housing Finance Commission. Residents and businesses undertaking new green construction or making energy efficiency improvements may be eligible for at least $50,000 of special financing. Interest rates of 2 - 4% are available. To qualify, a project should improve the site or entity's energy efficiency by at least 10%. Standard engineering reviews and pre/post-work energy audits apply. Additional information is available from the WSHFC website.

The Evergreen Sustainable Development Standard is Washington's green building rubric tailored for new affordable housing. Standards are based on LEED and incur points for compliance. Small energy efficiency practices can earn 1 point, using renewable energy (such as solar PV) can earn five points, and exceeding the total standard will earn 15 points. New affordable housing projects should earn at least 50 points; remodeling projects should earn at least 40 points. Additional information and a copy of the standard are available from the Washington State Department of Commerce.

The Sustainable Energy Program/Trust is a division of the Washington State Housing Finance Commission. Residents and businesses undertaking new green construction or making energy efficiency improvements may be eligible for at least $50,000 of special financing. Interest rates of 2 - 4% are available. To qualify, a project should improve the site or entity's energy efficiency by at least 10%. Standard engineering reviews and pre/post-work energy audits apply. Additional information is available from the WSHFC website.

Washington state law requires all public or private electrical utilities with a customer base of at least 25,000 to offer green power options. Customers can purchase 100% renewable energy in fixed blocks. This energy may be derived from solar, wind, biomass, hydroelectric, landfill gas, or a combination of these technologies. Each customer will be notified of the green power option on a quarterly basis. Annual reports on program uptake and resources are available from the state legislature.

In 2005, former Washington governor Christine Gregoire approved a legislative corporate tax cut for the state's solar energy device and component manufacturers. Current tax rates for these companies are at least 43% below the average liability. Tax incentives only apply to businesses producing silicon components, semiconductors, solar cells, converters, and other components directly involved in the production of photovoltaic energy. The special rates expire in 2027. Additional information is available from the Department of Revenue.

In Washington, any renewable energy system rated for under 100 kW is eligible for net metering. All public/private utilities and cooperatives must offer interconnection and net metering to new renewable energy customers. Upon agreeing to a net metering contract, the energy system's owner will have a bidirectional meter installed to measure net excess generation (NEG) sent back to the grid. Utilities will credit customer bills for NEG at an avoided-cost rate per kilowatt hour. Should generation exceed consumption for any given cycle, NEG credits may roll forward to subsequent months. Additional information is available from the Washington Utilities and Transportation Commission.

The Sustainable Energy Program/Trust is a division of the Washington State Housing Finance Commission. Residents and businesses undertaking new green construction or making energy efficiency improvements may be eligible for at least $50,000 of special financing. Interest rates of 2 - 4% are available. To qualify, a project should improve the site or entity's energy efficiency by at least 10%. Standard engineering reviews and pre/post-work energy audits apply. Additional information is available from the WSHFC website.

The Sustainable Energy Program/Trust is a division of the Washington State Housing Finance Commission. Residents and businesses undertaking new green construction or making energy efficiency improvements may be eligible for at least $50,000 of special financing. Interest rates of 2 - 4% are available. To qualify, a project should improve the site or entity's energy efficiency by at least 10%. Standard engineering reviews and pre/post-work energy audits apply. Additional information is available from the WSHFC website.