HEA looks to capture the wind

Utility discusses alternative energy viability in Alaska

Posted: Sunday, February 03, 2008

Giant white three-bladed wind turbines may not be showing up on the Homer Spit or the Kenai bluffs anytime soon, but engineers are scouring the Kenai Peninsula for the best place to site a wind farm.

As the renewable resource energy option becomes more economically attractive, Southcentral utility companies including Homer Electric Association are looking to augment existing electricity generation facilities, most of which are highly dependent on increasingly more expensive natural gas.

HEA officials and the Alaska projects manager for enXco, a renewable energy firm, met with Kenai Peninsula residents Thursday night at the Challenger Learning Center of Alaska in Kenai to describe the ins and outs of various forms of alternate energy, especially wind.

Steve Gilbert, the enXco executive, said his firm has teamed up with Cook Inlet Region Inc. in a joint venture to erect 24 huge wind turbines on Fire Island in Cook Inlet, approximately three miles off Ted Stevens Anchorage International Airport.

HEA is among four of the six utilities along Alaska's rail belt that have signed a memorandum of understanding to move the wind energy project forward, Gilbert said.

Because the mountains surrounding Turnagain Arm create a venturi effect, wind is forced out of the arm and directly across Fire Island, making it an ideal spot for a wind farm, according to Gilbert.

The joint venture, called "Wind Energy Alaska," looked at 21 prospective sites, installed weather monitoring instruments on 12 of the sites and "we found three that might pan out," Gilbert said.

Besides Fire Island, Arctic Valley east of Anchorage and Bird Point were considered, but Fire Island was determined to be most desirable.

HEA project engineer Brad Zubeck showed the 80 people attending Thursday's meeting a colored map of the Kenai Peninsula indicating areas in the Caribou Hills as being most favorable in terms of sustainable winds for an additional wind farm. Precise sites under consideration were not disclosed due to the competitive nature of the permitting process.

Zubeck said HEA would conduct a feasibility study on wind energy over the next one or two years.

Gilbert began his presentation on wind energy with a comparison of energy derived from frontier windmills of old to wind turbines of today.

"A windmill will capture about 5 percent of the wind energy," Gilbert said. "A modern wind turbine captures approximately 40 percent."

With three gigantic blades weighing 22,000 pounds each, the wind turbines turn slowly at 18 rpms, he said.

The typical turbine hub height is 262 feet above the base and the rotor diameter is 227 feet.

The wind turbines on Fire Island would produce enough power to meet the needs of 16,000 to 18,000 average-size homes.

Gilbert said, compared to other renewable energy forms including hydropower, solar, wave and tidal, geothermal and biomass, wind is "the lowest-cost renewable to us today."

Benefits of renewables, he said, are level prices for the power, a diversification of resources and reduced emissions.

"Fuel and purchased power expenses are running away," he said. "More than 90 percent of Southcentral's energy is fueled by natural gas."

Although the up-front costs of building and installing wind turbines are high, adding wind energy will stretch the natural gas supply and cost less in the long run.

"Think long term," Gilbert said.

One 10-year-old pupil in the audience, Megan English, who attends Soldotna Montessori Charter School, asked how long it would take to deliver and install the turbines on Fire Island and put them into production.

"After they arrive in Alaska, the 24 turbines on Fire Island would take five months to install," Gilbert said, adding enXco would seek to hire Alaska contractors to do the work, as well as possibly having some subcomponents manufactured in-state.

"One big concern is visual," Gilbert said. "Also birds and noise."

Using a computer model, he showed the audience how difficult it would be to see the Fire Island turbines from land, and he said at 18 rpms, the rotors do not pose much danger to birds. As the blades turn, they are relatively silent, though Gilbert said when a blade passes a person on the ground, one can feel the pulse of air being moved.

Infrastructure at Fire Island including a submarine transmission line under the inlet, is expected to cost $43 million, and the turbines will be between $75 and $95 million, he said.

"Employing economies of scale, ideally to produce 20 megawatts of power, 10 turbines would be needed on the Kenai Peninsula," he said.

The next steps in the process are baseline studies for the underwater cable to be conducted for the Army Corps of Engineers.

Phil Hermanek can be reached at phillip.hermanek@peninsulaclarion.com.

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