Tidal energy pursued in channel

Outside firms believe saltwater bodies may provide green energy

Posted: Thursday, July 27, 2006

Outside firms are speculating that Alaska's coastline might reap green power in the form of tidal energy.

In the last couple of months, Lower 48 firms have applied to federal regulators to study six saltwater bodies in Alaska for their tidal energy potential. Among them are Juneau's Gastineau Channel, Petersburg's Wrangell Narrows and Icy Passage, near Gustavus.

If feasible, the companies would generate electricity using large windmill-style turbines - potentially churning at 3 to 10 revolutions per minute - fixed to the ocean floor and linked by submarine cable to existing electrical transmission lines.

Proponents say the energy derived from ocean or tidal currents may have more potential than wind power, because water is 1,000 times denser than air.

"It's clean and renewable energy," said Charles Cooper, an engineering consultant for Oceana Energy Co., which is pursuing all three of the tidal energy projects in Southeast Alaska.

His company would have to study other potential environmental effects. Depending on how they are designed or located, the underwater devices could obstruct marine traffic or interfere with fish and marine mammals.

Still under testing by Oceana Energy's partners, the devices would include propeller blades 20 to 50 feet each in diameter, a generator, anchoring systems and transmission lines. Oceana Energy claims it can produce 500 kilowatts to 2 megawatts of electricity with the devices.

But in Juneau, the local utility may not be interested in purchasing new, emission-free energy anytime soon.

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Juneau's Alaska Electric Light and Power Co. will have enough clean hydropower to furnish Juneau's growth for at least a decade or 15 years, spokesman David Stone said.

Oceana Energy hasn't yet talked to AEL&P or other utilities in Southeast Alaska. For now, the firm, based in Washington, D.C., is busy seeking preliminary permits throughout the United States for tracts of ocean that appear to have strong tides.

Corporate interest in tidal power was buoyed by a recent international study by the Electric Power Research Institute, based in Palo Alto, Calif.

The study touted the potential benefits of tapping tidal flows in specific locations throughout North America, including Alaska's Knik Arm.

"A lot of people are interested, suddenly," said Celeste Miller, a spokeswoman for the Federal Energy Regulatory Commission.

If Oceana Energy receives preliminary permits for its projects in Alaska, it will be able to pursue studies for three years without fear of competition from other firms.

The studies could cost $1 million to $4 million per site, according to the firm.

Cooper did not know this week if Oceana Energy will push forward with its proposed Alaska projects. That decision will depend on further studies of the technology, possible user conflicts, such as navigation and fishing, and economic considerations, he said.

Environmental factors may already be at play in other areas of Alaska. For now, the Alaska Energy Authority is not actively promoting tidal energy development in Knik Arm due to concern about the possible federal endangered species listing of beluga whales, said David Lockard, an engineer specializing in tidal energy for the authority.

So far, the Federal Energy Regulatory Commission has received 22 preliminary permit applications for tidal energy around the United States, including the six in Alaska.

Eleven permits have been granted so far, but the six in Alaska are still pending, Miller said.

One of Oceana Energy's competitors, Maryland-based Verdant Power, has complained to federal regulators that Oceana Energy's permit applications show a lack of familiarity with water-based energy projects.

Verdant further accused Oceana Energy of plotting to "bank the sites and auction them off for its own private gain when tidal technology matures."

Oceana Energy states it is working with the U.S. Navy and NASA on testing its proposed turbine technology in the ocean.

In addition to its three sites in Southeast Alaska, Oceana Energy also has applied for a permit to study tidal energy in Kachemak Bay, near Homer.

A Miami-based firm, Ocean Renewable Power, wants to study tidal energy in Anchorage's Knik Arm and at Resurrection Bay, near Seward.

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