Alaska is home to more than 365,000 miles of rivers and 33,000 miles of coastline, making it an epicenter for hydropower development in the U.S.

Dependent on expensive heating fuel and diesel-fired generation, Alaskan officials have identified more than 200 promising sites for hydropower development and pledged to produce 50 percent of the state’s electricity from renewable resources by 2025. To get there, Alaska will rely largely on its roaring rivers and strong ocean tides and currents.

Tapping Alaska’s vast hydropower potential is a major element in Alaska’s plan to create jobs and provide much needed electricity to isolated communities throughout a state that is bigger than Texas, California and Montana combined.

“We have more energy potential than just about anywhere in the world,” said U.S. Sen. Lisa Murkowski, R-Alaska. “Our problem is how we harness it when we’re looking at economies of scale.”

For Alaska, small hydropower projects represent the best way to supply electricity to scores of small, isolated villages across the state, said Murkowski, sponsor of the Hydropower Improvement Act, a bill pending before the full Senate.

“It’s clean, it’s efficient and it’s inexpensive,” she said.

Best of all, it would displace diesel-fired generation, an expensive and polluting form of generation widely used in villages throughout the Railbelt region.

For hydropower developers, Alaska is an ideal place to build new projects because of the state’s high energy costs, abundant resources and a state law establishing an ambitious goal for renewable generation.

Last year, the Alaska Center for Energy and Power estimated that Alaska accounts for 40 percent of the United States’ potential to generate electricity from rivers and 90 percent of the nation’s potential to produce power from tidal resources. 

But the potential of Alaska’s hydrokinetic resources won’t be met until the industry can prove the technology can withstand Alaska’s harsh and turbulent conditions. Researchers and developers are testing several technologies in hopes of resolving issues related to anchoring, installation, performance and viability. 

Already, hydropower accounts for 24 percent of the state’s electricity consumption, with 50 hydroelectric facilities that produce more than 1.3 million megawatt-hours each year, according to the Department of Energy. 

Speaking to members of the National Hydropower Association during a regional meeting in September, Alaska Gov. Sean Parnell said the construction of new hydropower capacity is central to the state’s plan to create economic opportunity for Alaskans. 

“Alaska’s roaring rivers can light and heat our homes during the dark winter nights,” Parnell said. “Hydropower will put us far down the path to achieving our goal of 50 percent renewable energy for electricity by 2025.” 

U.S. Sen. Mark Begich, D-Alaska, said hydropower should be the heart of any comprehensive plan to increase renewable energy.

“If you want to be serious about renewable energy, hydropower has to be part of the discussion,” Begich said. “Nowhere is that more true than Alaska, which holds over a third of our country’s untapped hydropower.” 

Several hydropower projects are in some stage of development throughout Alaska’s Railbelt area, including a 600-MW project on the Susitna River, several tidal projects in the Cook Inlet and a small 5-MW project near Hydaburg on Reynolds Creek.

Hydro Review examined these and other Alaska projects that best illustrate the types of new developments that are being pursued in Alaska. What follows is a description of those projects.

Reynolds Creek 

The 5-MW Reynolds Creek project is under construction about 10 miles east of Hydaburg, Alaska, on Prince of Wales Island.

Construction began in 2010 and is expected to be completed late in 2012. Haida Corp. owns 75-percent of the project and Alaska Power & Telephone owns 25 percent.

The facility will use 750-feet of head to produce, on average, 19.3 million kilowatt-hours of electricity annually. Alaska Power Co. will construct and operate the facility and purchase the power.

The island is already home to two hydropower projects: 4.5-MW Black Bear Lake and 2.3-MW South Fork. But most of the island’s electricity is diesel-fired. 

The project includes a 28-foot-long, 6-foot-high diversion structure, a 3,200-foot-long penstock, a 5-MW powerhouse and a 12-mile transmission line that will interconnect with existing transmission. The project also will create 600-acre feet of storage at Rich’s Pond and Lake Mellen.   

Whitman Lake

Construction of the 4.6-MW Whitman Lake project near Ketchikan in southeast Alaska is expected to begin in July 2012 and should be up and running by December 2013.

The 39-foot-high, 220-foot-long concrete gravity arch dam and hydro project will include two 2,450-foot penstocks that lead to each generating unit at Whitman Dam. The City of Ketchikan expects to award the general construction contract for the project in May 2012.

The project will produce, on average, 16,500 megawatt-hours annually and will include two turbine generators with a maximum hydraulic capacity of 180 cfs, a 40-foot-wide Ogee spillway and a 1,500-foot-long transmission line. 

Mahoney Lake

The Federal Energy Regulatory Commission issued a license for the 9.6-MW Mahoney Lake project, five mile northeast of Ketchikan, in January 1998. 

But the project was put on hold and the license was stayed until a 57-mile-long, 138-kV transmission line could be built. 

The transmission line has been completed and the developers – the City of Saxman, Alaska Power & Telephone and Cape Fox Corp. – have reestablished a public-private partnership to build the $46 million project. The partnership is now seeking funding for the project.

While the start of construction is still uncertain, the developers hope to complete the project in June 2016. It will be built on Upper Mahoney Lake about five miles from Saxman and three miles from the Swan-Tyee and Beaver Falls transmission lines.

Officials estimate the Mahoney project will displace about 46,000 megawatt-hours of diesel-fired generation or 3.1 million gallons of diesel each year.