These are helpful tools for understanding your solar potential, but they do not replace the expertise of having a professional solar installer assess your property.  

Some factors that may impact the suitability of your roof for solar include: 

• Direction: South-facing is ideal though east and west-facing roofs may still produce significant amounts of electricity. 
• Shading: Solar panels should have direct access to the sun with limited shading. Nearby buildings, trees, hills, or other roof features can reduce the amount of sunlight reaching your solar system.  
• Pitch: The ideal roof angle is between 20 and 35 degrees though steeper and flatter roofs may still work.

You can estimate the performance of potential photovoltaic (PV) projects using the National Renewable Energy Laboratory’s PVWatts Calculator.

If a solar installer determines that your roof is not suitable for solar, or you don’t own your own home, you can still access the benefits of solar energy by enrolling in a community solar project. Community solar is a solar-ownership structure where a group of community members participate in a single solar project and share its benefits.  

Olympia Community Solar and Puget Sound Energy (PSE) both offer local community solar projects in Thurston County.

Rural Energy for America Program (REAP) Renewable Energy Systems & Energy Efficiency Improvement Guaranteed Loans & Grants

REAP provides guaranteed loan financing and grant funding to agricultural producers and rural small businesses for renewable energy systems or for energy-efficiency improvements. Agricultural producers may also apply for new energy-efficient equipment and new system loans for agricultural production and processing.

Community Property Assessed Clean Energy and Resiliency (C-PACER) Financing Program

C-PACER is an alternative loan program that allows owners of eligible commercial properties to seek long-term financing from a private-capital provider for energy efficiency, renewable energy and resiliency improvements. C-PACER loans are tied to the property, rather than the owner, through an annual property assessment managed by a third-party capital provider. In 2021, the Thurston County Board of Commissioners passed a C-PACER ordinance, enabling commercial property owners in Tumwater and Thurston County to access this innovative financing tool.

Net metering
Net metering allows owners of grid-connected, renewable-energy systems to receive credit for excess electricity produced by their systems. Net-metered systems that produce more electricity than needed are credited for the excess production at retail-electric rates on the next month’s utility bill. Credits in Washington state carry forward month to month but not year to year. Credits zero out on March 31, at which point a new net-metering year begins.

State sales-tax exemption
The State of Washington provides a sales-tax exemption on all equipment, labor and services related to the installation of solar systems generating less than 100 kW of electricity (most homes only require a 5 to 12 kW system). This exemption applies to installations from July 1, 2019, through December 31, 2029.

Federal income tax credit
New residential solar-PV systems installed from January 1, 2006, through December 31, 2023, are eligible for the Federal Solar Investment Tax Credit (ITC). The ITC provides a 30-percent tax credit for systems installed from January 2022 until the end of 2033, when it declines to 26-percent. Nonprofits and Tribes may claim the credit through a direct-pay option. 

The City of Tumwater wishes to encourage the use of solar energy. Solar photovoltaic systems are allowed in all zoning districts when conforming to certain requirements. For more information, read the Zoning Determination Letter.

Zoning Determination Letter

All residential solar PV installations require a permit before starting any work. Most solar contractors will apply for any permits on your behalf. Visit the City’s Permit Services webpage or any of the specific pages below for more information. 

Permit Application for Residential Solar
Permitting Checklist for Solar
Fee Schedule
Schedule an Inspection
Solar Fact Sheet

The City of Tumwater allows ground and roof-mounted solar panels as an accessory use as long as they service the primary building or structure. Some exceptions for designated historic buildings or buildings in historic districts may apply.

Homeowner's Associations
In the state of Washington, a homeowner’s association may issue guidelines related to the visibility and aesthetics of solar-panel placement but may not prohibit a resident or owner from installing a solar panel if the panel meets these criteria. This is authorized by RCW 64.38.55.

Solar Easements
A solar easement allows property owners to legally protect their access to sunlight for a solar-energy system. In Washington, property owners may enter into voluntary solar easements to ensure adequate sunlight for their solar-energy system. Without a formal easement, property owners are not able to require the removal of obstructions on adjacent properties. This is authorized by RCW 64.04.140 and RCW 64.38.055.