Anchorage Daily News

WASILLA -- A tidal generator planned for testing in the Knik Arm this year might not hit the water until 2011, according to project leaders at Ocean Renewable Power Company.

The company, led by Chris Sauer of Tampa, Fla., had planned to test its tidal-powered turbine at Port MacKenzie this year.

Douglas Johnson, project director for the company in Alaska, said Ocean Renewable narrowed early field-testing plans for its turbine generator unit to a single project in Maine instead of testing two projects simultaneously.

"We want to make sure we've got a really bombproof product as we develop and deploy these modules," Johnson said. "And we want to make sure we have very, very controlled testing environments. We have that in Maine."

This winter the company tested a $1.2 million prototype unit attached to the bottom of a barge in Eastport, Maine, Johnson said. The test ran from December through April 25. Johnson said despite occasional harsh weather, the tests went well.

"We were able to create electricity with the device in a very smooth power curve," he said.

The news wasn't all good. The company is modifying its design as a result of the tests.

"We didn't get the power we would have liked to have," he said. The blades that spin the turbine are being redesigned to take better advantage of the water flow, he said.

Each so-called OCGen unit generates about 250 kilowatts of energy when the forces of incoming or outgoing tides spin two blocks of push-mower-type blades. Stack four of the units together and they make up an OCGen module, about the size of a 40-foot Conex trailer, Johnson said. Each module should generate about one megawatt of energy.

The testing showed that the blades began spinning with the incoming tide sooner than expected, and they continued to rotate longer after the tide slowed. But the unit generated less power than expected, Johnson said.

According to information on the company's Web site, more efficient blades were installed in April. With the first round of testing complete, the company plans to move to commercial product design.

While commercial tidal generators are being designed, the company plans to start another project in Alaska. Johnson said Ocean Renewable is working with the city of Nenana to deploy a small in-river generator that depends on current strength to push its blades.

The module would be placed in the Tanana River next summer, Johnson said. The project is predicated on funding, he said.

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