Boat, Anchor, and Tidal Generator (USA)


When summer comes and the fishing crews return, electricity demand rises by 40% or more. For Nushgak Cooperative, that creates a dilemma: The utility needs a plant big enough to generate that electricity, but the extra capacity goes unused in the winter, and customers have to pay for a plant that is partly idle. Now city leaders are thinking about how to improve overall energy efficiency by improving the efficiency of the salmon fleet.

Wind turbines aren’t a perfect solution—winds here tend to die down in summer. But the answer might be right beneath their hulls. The Environmental Science Lab has taken the lead in an ambitious proposal to draw electricity from the tides.

How would it work? According to Radenbaugh, a tidal generator—a “low-flow, in-stream hydrokinetic turbine system”—could become part of a barge that produces the ice needed to store the fresh-caught fish, or perhaps part of a floating fish-processing plant. The craft would operate in Nushagak Bay; as tides flow in from the Bering Sea through Bristol Bay, the water would turn the turbine and generate power.

“There would be no permanent structures in the water to impede fish migration,” he said. “The only thing in the bay is the anchor, and the barge, with the tidal generator.” The University of Alaska Fairbanks and partners hope to test a prototype at the confluence of the Nushagak and Wood Rivers in 2012.

With consumer tastes moving away from canned salmon, the processing industry based in Dillingham is moving toward more fresh or flash-frozen fish. To demonstrate how that evolution could boost the local economy, Radenbaugh points to salmon from Alaska’s Copper River, which fetches premium prices around the world.

“There’s a reason they can charge twice as much—they know how to take care of the fish,” he says. “The key, for quality fish, is chilling. People want fresh fish now, and fresh products require chilling.”

And today chilling requires diesel—until researchers, working with Alaskan political and business leaders, can generate an alternative.


Source: aaas, October 04, 2011