Homer Alaska - News

Story last updated at 3:21 PM on Wednesday, February 1, 2012

Massive energy potential waits to be tapped in Alaska's waters

BY Hal Spence
For the Homer News

Waves and tidal currents off Alaska's coastline would generate more than 850 terawatt-hours of electrical energy annually if fully developed, according to two reports recently released by the U.S. Department of Energy.

Much of that potential lies untapped in the waters of the Cook Inlet region, a location already under study by hydrokinetic energy companies.

Federal resource assessments of the national coastline show wave action and tidal streams could "contribute significantly" to and diversify the country's energy supply, according to a Jan. 19 Department of Energy press release. That clean and renewable energy, when combined with conventional hydropower and other water resources, "can potentially provide 15 percent of our nation's electricity needs by 2030," the DOE said.

The two federal reports, "Mapping and Assessment of the U.S. Ocean Wave Energy Resource," and "Assessment of Energy Production Potential from Tidal Streams in the U.S.," represented "the most rigorous analysis" yet of the nation's ocean energy resources, DOE said.

One company already engaged in developing hydrokinetic resources in Cook Inlet under permits from the Federal Energy Regulatory Commission is Ocean Renewable Power Co., or ORPC, which has partnered with Homer Electric Association.

The two companies are engaged in monitoring the inlet environment and assessing and characterizing a site off Nikiski in the East Forelands area of the inlet.

ORPC, which has been developing tidal power systems since 2004, hopes to produce power for the Railbelt electrical grid by 2014, said Doug Johnson, director of business development for the company. Plans announced early last year called for a 150-kilowatt pilot project to be up and running in the water in 2013. However, Johnson said, those plans were pushed back a year to allow ORPC to fully concentrate on powering up its first commercial-scale generation system this coming spring in Cobscook Bay, Maine.

"It will be our first fully grid-connected tidal generation system," he said. "It will put us on the world stage as a pre-eminent energy company."

The Cobscook Bay system is similar to that planned for the East Forelands project, Johnson said, adding that while the work in Maine proceeds, the company will continue environmental assessment and site characterization work here.

In a press release early last year, ORPC President and CEO Chris Sauer said tidal resources in Alaska represented 90 percent of the total potential of the country. In the same release, HEA General Manager Brad Janorshke said the pilot project fit into the electrical cooperative's strategic goals.

"As HEA looks for ways to lessen its dependence on natural gas, exploring renewable energy options is a priority of the cooperative," Janorshke said.

ORPC's FERC permit allows the company to study the area of the East Forelands and then to submit a license application for a pilot tidal project that could eventually produce up to 5 megawatts of electricity, enough to energize about 2,300 homes. ORPC also has a permit to study the tidal energy potential off Fire Island. Eventually, Johnson said, ORPC could have energy producing stations along the entire length of Cook Inlet.

"Cook Inlet is truly a world-class resource," he said. "Over 20 years, tidal systems built throughout the Inlet could take advantage of its unique layout."

Tidal energy is predictable, but, naturally, cyclically intermittent, Johnson said, but with enough spaced production sites, energy could be generated and fed into the Railbelt Grid continuously.

The fully operating 600-kilowatt demonstration project ORPC hopes to have running in 2014 would involve four 150-kilowatt tidal generators (ORPC's TidGen Power System), machines that sit on the Inlet bottom in relatively shallow water. Scaling up to a functioning commercial-scale 5-megawatt generating system would require also utilizing several ORPC's OCGen Power System modules that are designed for use in deeper water, Johnson said.

"Conservatively speaking," the Inlet could be the source of certainly hundreds of megawatts, perhaps even a gigawatt, Johnson said. While ORPC's efforts shouldn't be seen as a silver bullet for the Railbelt's energy future, it is possible Inlet tidal fluctuations could produce 10 percent to 15 percent of those energy needs.

"It's too early to say, but we think we can be a significant contributor to the energy mix of the Railbelt over time," Johnson said.

Tidal energy in the Railbelt region is also being explored in Turnagain and Knik arms in the Upper Cook Inlet.

The U.S. currently consumes about 4,000 terawatt-hours (TWh) of electricity a year. Theoretically, roughly a third that much (1,420 TWh) could be produced from waves and tidal currents, though it is unlikely all that potential could be developed, DOE said.