|
In-river turbine arrives in Alaska Project will test the feasibility of using river current to generate more affordable power for rural village in southwest Alaska Alan Bailey Petroleum News
Several years after being discussed as a concept at an Arctic Energy Conference, Ocean Renewable Power Co.’s prototype in-river electricity generation device has finally arrived in Alaska for testing in the Kvichak River, as a potential power source for the village of Igiugig near the end of Lake Iliamna in southwest Alaska. The idea is to place the device on the river bottom for a couple of months this summer, to test the effectiveness of the system as a power source; test the deployment and retrieval of the device from the river; and monitor the interaction of the device with the river environment.
If the test deployment proves successful, Ocean Renewable Power, or ORPC, hopes to make a more permanent installation of a similar device next year, Christopher Sauer, president and CEO of ORPC, told Petroleum News May 20, following the unveiling of the prototype device, in transit in Anchorage.
Rural power supply Referred to as hydrokinetics, the in-current technology uses a submerged water turbine to gather energy from flowing water, either in a river or in the form of an ocean tidal current. ORPC has deployed a hydrokinetic tidal power system in Maine and now wants to try a similar, scaled-down system in an Alaska river. If successful, this type of system might provide a practical source of electrical power for rural Alaska villages, many of them located next to flowing water.
AlexAnna Salmon, Igiugig Village Council president, said that, with diesel-generated village power costing about $1 per kilowatt hour for commercial operations, her village welcomes the hydrokinetic industry “with open arms and an open mind,” and that the village thanks the various organization that have helped with the funding of the project.
“The people of Igiugig have always treasured the Kvichak River as being the purest water on the planet, for being the most scenic throughway to Bristol Bay and for bringing the most incredible salmon runs left in the world,” Salmon said. “But our people also pay for some of the highest cost electricity and heating fuel in the nation.”
Sauer said that, if successful in Alaska, the in-river turbine system could find application in remote regions elsewhere in the world, in northern Canada and southern Chile, for example.
AEA funding support Sara Fisher-Goad, executive director of the Alaska Energy Authority, or AEA, said that the project represents a triple play for her agency, in that it involves the implementation of new energy technology, the reduction of village energy costs and the use of a renewable energy source. AEA has provided funding support for the project through the state’s Emerging Energy Technology Fund. Several other organizations have been assisting the project, including the Department of Energy, the Denali Commission and the University of Alaska. The hydrokinetic system could meet up to half of Igiugig’s electricity demand, Fisher-Goad said.
The in-river device has helical shaped blades, in a cylindrical configuration, connected to a central generator. The device will be bolted to a pontoon and sunk to the river bottom for operation - the pontoon will hold the device in position, preventing the device from overturning in the strong river current.
Efficient design Doug Johnson, ORPC’s director of business development for Alaska, told Petroleum News that the use of the helical design, rather than the use of a more conventional propeller-like turbine, improves the performance of the device in turbulent water. Essentially, the “blades” of the turbine act like underwater wings, pulling the blade system around. With blunt edges and a rotation speed of just under 50 revolutions per minute, the turbine rotor system should not harm any wildlife, Johnson said, commenting that after thousands of hours of operation with similar devices in Maine, no negative environmental impacts had been observed.
“The larger fish seem to sense it’s there and swim around it. The smaller fish actually go right through,” Johnson said.
Potential damage to turbine blades from river debris has proved to be a challenge for previous plans for in-river power generation in Alaska - the University of Alaska Fairbanks has been developing a debris mitigation system for application in rivers such as the Yukon or the Tanana. But, coming directly out of Lake Iliamna, the Kvichak River is debris-free at Igiugig, Johnson said.
Sauer said that the river is also ice-free, except in May when ice tends to be carried out of the lake. Once fully operational, the idea would be to place the system in the river in early June each year and then remove it again in mid-April, before the ice starts flowing, he said.
Commercial challenges Currently, the biggest commercial challenge facing the nascent hydrokinetics industry is raising capital in a world where renewable energy competes with cheap natural gas, Sauer said. There are also permitting and licensing hurdles, with the regulatory process for installing a small-scale hydrokinetic system being similar to that for a major hydroelectric dam, he said.
But, as with wind energy, once production moves from individual devices to the manufacture of hundreds of machines, the economies of scale will bring costs down, Sauer said.
ORPC has also been working with Homer Electric Association to investigate the implementation of an in-current generation system using Cook Inlet tidal currents at East Foreland on the west side of the Kenai Peninsula. The company is also interested in implementing a tidal power system in False Pass, a narrow ocean channel between the Alaska Peninsula and the easternmost of the Aleutian Islands.
|
