River turbine to be tested at rural Alaska village

A company that hopes to build underwater river turbines as a clean power alternative to diesel in Alaska villages has unveiled a prototype due to be tested in July.

Ocean Renewable Power Co., based in Portland, Maine, showed off its RivGen Power System last week in Anchorage. The device built with backing from the Alaska Energy Authority and the Denali Commission will be installed in July on the bottom of the Kvichak River to generate power for Igiugig, a community of 50 about 250 miles southwest of Anchorage.

The device is a scaled-down version of turbines the company has built for harnessing tidal power.

“The good news is, sustainable river energy has now arrived in Alaska,” said Christopher Sauer, ORPC chief executive officer.

The turbine is 40 feet wide and has two sets of 15-foot blades. Lt. Gov. Mead Treadwell said it reminded him of a farm thresher.

In a river flowing at 6 knots, the blades will turn at 49 revolutions per minute. Company officials estimate it will provide up to half of Igiugig’s electricity.

The unveiling in Anchorage was appropriate, Sauer said. He spoke at a 2007 Arctic Energy Conference about his company’s devices that harness tidal power.

“People came up to use and said, ‘Can’t you make this smaller? Would it work in river?” Sauer said.

AlexAnna Salmon, president of the Igiugig Village Council, said heating oil sells for $7.53 per gallon in her village and the cost of commercial power is $1 per kilowatt hour.

“We are welcoming the hydrokinetic system with open arms and open minds,” she said.

The turbine will be barged from Homer. It will be fitted to a pontoon support structure fabricated in Alaska that will float the turbine into position in the river. When in place, the pontoons will be filled with water to lower the turbine to the river floor.

The company has permits to operate the turbine through September. A crucial part of its review will be how well it hooks into the village power grid and its effects on fish. At least three underwater cameras will monitor fish movements in the crystal-clear Kvichak River, which flows from Lake Minchumina at the village.

Larger fish tend to sense a turbine’s presence and avoid the blades, said Doug Johnson, the company’s director of business development. Small fish swim through it, he said.

The company calls testing at Igiugig a crucial step in commercializing the technology. Ocean Renewable will take what’s learned and incorporate it into a revised design, Sauer said.

The company’s biggest challenge is raising capital, he said. With cheap natural gas, people say there’s no immediate need to invest in renewables.

“If we can raise the money, I would say in two years, we’ll be in production,” he said. He estimated a 25-kilowatt unit installed would cost a village about $500,000.

“The capital seems a little high, but free fuel costs,” Sauer said.