Supplying 25% of the state’s electricity

Hydroelectric power, Alaska’s largest source of renewable energy, supplies roughly a quarter of the state’s electricity in an average water year. In 2018, 50 hydro projects provided power to Alaska utility customers, including the Alaska Energy Authority owned 120-MW Bradley Lake project near Homer, which supplies about nine percent of the Railbelt’s electricity.

Most of the state’s developed hydro resources are located in Southcentral, the Alaska Peninsula and Southeast – mountainous regions with moderate to high precipitation. Outside the Railbelt, major communities supplied with hydropower are Glennallen, Haines, Juneau, Ketchikan, Kodiak, Petersburg, Sitka, Skagway, Wrangell, and Valdez. 

King Cove is now saving more than 83,000 gallons of diesel per year.

The Waterfall Creek Hydro project in King Cove, commissioned in 2017, is saving the community about 60,000 gallons of diesel per year. Combined with the community’s first hydro project on Delta Creek, King Cove is now saving more than 83,000 gallons of diesel per year and frequently meets their 2 MW demand in the silence of diesels-off.

In 2014, Kodiak Electric Association installed a third 10-MW turbine at their Terror Lake hydro facility, increasing powerhouse capacity to 30 MW. This added capacity enables peak load demands to be met without operating diesel generators. Terror Lake also helps to regulate the 9-MW wind farm at Pillar Mountain allowing Kodiak to meet its power demand with nearly 100 percent renewable energy. 

Other projects provide hydro storage without dam construction through the natural impoundment of existing lakes. The 31-MW Crater Lake project, part of the Snettisham project near Juneau, includes a “lake tap” near the bottom of the lake that supplies water to a powerhouse at sea level through a 1.5-mile long tunnel. 

Still other projects increase annual energy production by diverting rivers to existing hydroelectric storage reservoirs and power plants. These projects allow more efficient use of existing infrastructure, including intake structures, dams, powerhouses, generation equipment, roads and transmission lines. Projects like this include the Stetson Creek diversion to Cooper Lake near Kenai Lake, West Fork Upper Battle Creek diversion at Bradley Lake and the Waterfall Creek project at King Cove. 

Smaller, “run-of-river” projects use more modest structures to divert a portion of the natural river flow through penstocks to turbines making power. The 824 kW Tazimina project near Iliamna diverts water into an intake 250 feet upstream from a 100-foot waterfall through a steel penstock to an underground powerhouse, and then releases it back into the river near the base of the falls. Other run-of-river projects include Falls Creek at Gustavus and Chuniisax Creek in Atka. Projects at Packers Creek in Chignik Lagoon and Gartina Falls near Hoonah have recently been completed.

Related Resources

HydroRailbeltRenewable TechnologiesRural Alaska