Generation
Generating clean and renewable energy
Grant PUD operates two Columbia River dams along the Columbia River. We also have wind power from the Nine Canyon Wind Project and solar power from the Goose Prairie Solar Project in our power portfolio. These resources have the collective capacity of more than 2,200 Megawatts.
Hydropower
Our two Columbia River dams and smaller hydropower projects have a generating capacity of more than 2,100 megawatts of clean, renewable energy. Priest Rapids and Wanapum dams, collectively known as the Priest Rapids Project, are licensed by the Federal Energy Regulatory Commission (FERC).
These locally-owned and operated hydroelectric resources enable Grant PUD to provide our customers with some of the lowest-cost, most-reliable electricity in the country. We've invested — and continue to invest — millions of dollars to modernize turbines and generators at both dams. This investment maximizes the potential energy flowing through the Columbia River and provides safer fish passage.
Wanapum Dam
Wanapum Dam is located on the Columbia River, six miles downstream of Vantage, Wash., 18 miles upstream of Priest Rapids Dam and 415 miles above the mouth of the river. The dam was named Wanapum in honor of the band of Native Americans who live along a stretch of the Columbia River from Vantage south toward Pasco, Wash. Wanapum Dam was financed by long-term revenue bonds that were retired through the sale of power. No tax money or government appropriations were used for construction of Priest Rapids or Wanapum dams.
CONSTRUCTION START
1959
POWER GENERATION BEGAN
1963
GENERATION UNITS
10
RATED CAPACITY (megawatts)
1,221.6
CONCRETE/EARTHFILL LENGTH
8,637 FT
RATED HEAD
80 FT
Priest Rapids
Priest Rapids Dam is on the Columbia River, 24 miles south of Vantage and 200 miles downstream of Grand Coulee Dam. It was named in recognition of the Wanapum religious leader Smohalla and the small band of indigenous people who lived during the winter at a village near the last of seven rapids, called Priest Rapids. A small group of the Wanapum continues to live at the west bank of the dam.
GENERATION UNITS
10
RATED CAPACITY (megawatts)
950
CONCRETE/EARTHFILL LENGTH
10,103 FT
RATED HEAD
78 FT
CONSTRUCTION BEGAN
1956
FIRST POWER GENERATIOIN
1959
Other Renewable Energy
Solar
Grant PUD has added solar generation to our energy portfolio to supplement the generation from our Columbia River dams, Priest Rapids and Wanapum. Solar power increases our capacity to meet our customers’ demand for electricity.
Solar energy with battery storage helps enable Grant PUD to participate in the “Western Resource Adequacy Program (WRAP),” a coalition of Western utilities who have agreed to share the output from their generation resources when one or more of them is facing an energy shortfall. Our participation in this coalition is crucial for gaining access to day-ahead and real-time markets – sources of increased revenue from our surplus power. It also helps ensure the Pacific Northwest can reliably meet its demand for electricity into the future.
Solar energy also helps keep us on track to meet our state’s clean-energy goals. Read more about our expanding plans for solar in our 2026 Integrated Resource Plan.
Our current solar lineup:
Goose Prairie Solar: Since 2024, Grant PUD has purchased all the output, under contract, from this 80-megawatt solar project near Moxee, Washington.
Quincy Solar: This 120-megawatt solar project broke ground Aug. 18, 2026 northeast of Big Bend Community College in Moses Lake. Grant PUD will buy all the project’s output under a 20-year contract with the project’s developer, Chicago-based Invenergy. Operation is slated to being in 2027.
Royal Slope Solar: Planned for 3,232-acres of private land upriver of Wanapum Dam, the Royal Slope Solar development will include a 260-megawatt array of solar panels that will charge batteries, on site, with capacity to store and supply 260 megawatts of energy for up to four hours. Grant PUD will purchase all the project’s output, under 20-year contracts with the project developer, Clearway Energy. Developers expect to break ground in November 2026 and begin generating in early 2028.
Wind
Grant PUD holds contracts for a 12.54-percent share of the power generated by the Nine Canyon Wind Project, owned by Energy Northwest near Kennewick, Wash.
Generation begins with wind speeds at 8 mph
Peak power generation at 35 mph
The turbines automatically shut down if sustained winds exceed 55 mph
Geothermal
Researching the potential:
Chelan, Douglas and Grant PUDs started a $22 million joint research project to study if geothermal is feasible and practical in the three-county area. The research includes geophysical surveys and below ground research to study temperature changes with depth, rock type, structural geology
Nuclear
Grant PUD is in the early stages of developing another source of electricity for our growing county that is as reliable as hydropower and as clean.
Grant PUD staff have done extensive analysis over the past five years on the feasibility to develop a nuclear plant using state-of-the-art, “small, modular reactor” technology. In 2024, we purchased 960 acres northeast of Moses Lake for a potential “energy park” that could include nuclear, solar, and/or a battery storage system.
Small, modular nuclear technology uses smaller reactors that are manufactured offsite and transported, ready-to-install, onsite. They’re used in tandem to generate electricity from nuclear fission. The technology is safer than traditional nuclear power and can be expanded by adding additional reactors, as needed.
Nuclear energy is available around the clock, like hydropower, and is carbon free, contributing to our state’s clean-energy goals.
Between permitting and lead time needed to order reactors and other plant components, it will likely be decades before plant development would be possible. For now, this technology seems the most feasible to supplement our dams with 24-hour available power.
Wholesale Power Services
Grant PUD offers many services on an as-negotiated basis with creditworthy counterparties. Services include wholesale scheduling services, various forms of wind integration and most types of energy, capacity and renewable energy products.
Exploring Bonneville Power Administration Contract
Learn more about potential future long-term generation resources.