Alaska geothermal power: Alaska energy authority overview of projects.
Positioned along the highly active Ring of Fire that arcs across the Pacific Rim, Alaska not surprisingly offers a landscape dotted with natural geothermal features--active and dormant volcanoes, regional hot springs, and the like. For those looking to harness such natural energy to create power and end-use heat, the 49th state is one of opportunity.
The state's geothermal resources are focused in three primary areas: first, the Ring of Fire encircling the Pacific and that includes the Aleutian chain, Alaska Peninsula and Wrangell range; second, a sweep of hot springs stretching from the Seward Peninsula to Canada; and Southeast Alaska's collection of hot springs scattered throughout the island region.
The attraction to natural heat sources-for warmth and therapeutic reasons-is a theme present throughout the state's colorful history, fueling early tourism development last century at places as remote and far-flung as southern Southeast Alaska's historic and now-closed Bell Island hot springs resort along Behm Canal; the much-visited wooden soaking tubs of the Chief Shakes hot springs along the Stikine River northeast of Wrangell that are now managed by the U.S. Forest Service; and the pre-World War II Bailey Bay hot springs resort north Ketchikan on the Cleveland Peninsula.
Nowadays, aside from the well-known visitor hot-spot Chena Hot Springs Resort--which also captures its own natural resource to provide power via the state's first and only geothermal power-producing plant--much of the current interest in Alaska's natural geothermal energy is for commercial and industrial reasons: power generation, geothermal heat pump efforts, and direct-use intent (capturing heated fluids to directly use the heat to warm a space or greenhouse). That said, the lure of warm water sources amidst the cool landscape of Alaska continues today to draw visitors, modern day explorers, and developers, alike.
Alan Baldivieso, program manager of the Alaska Energy Authority's Geothermal, Hydrokinetic and Emerging Energy Technologies effort, speaks to the scope of the state's geothermal zones and current projects afoot.
"Alaska's got a tremendous amount of geothermal potential," affirms Baldivieso. "It's also a very big state and the resources are very spread out. The upshot is that there is a tremendous amount of exploration that needs to occur."
Of the three categories of geothermal projects--power production, heat pumps and direct use--"the more expensive projects are clearly the power generation projects," he says.
Assessment & Exploration
Chena Hot Springs is the only power producing project currently online. Other geothermal projects around the state are in various stages of assessment and exploration. The lifecycle for such projects typically includes an assessment of the resource, drilling of test or "exploration" wells, drilling of production-level wells, and then the ultimate plant design and construction.
Chena Hot Springs
In the electrical production arena, the Chena Hot Springs Resort is the prime example in the state of an entity that uses its own natural geothermal resource to help meet its electrical requirements. As the state's first and only power-producing geothermal plant, according to Baldivieso, the 400-kilowatt (kW) plant came online in 2006. "It's fairly groundbreaking in nature," he says, as the plant takes a low-temperature resource--in the 160-degree Fahrenheit range--and uses it to produce power. "That's considered a pretty low temperature resource," he explains, as such power generation efforts typically require much higher temperatures from the geothermal input. The project is innovative, in that it considered what was available and crafted a plan to make it work, including a custom-designed and manufactured turbine system. "That's what they had to work with," he says of the natural resource. The plant provides power to the resort to help offset its generator use.
The project design included installation of two, 200 kW Organic Rankine Cycle geothermal power plants for a combined generating capacity of 400 kWs. The plant operated in the years since with 95 percent availability and moved the historic diesel generation use to that of backup and supplemental source, reducing the cost of power for the facility by an estimated 25 cents per kW hour.
Exploration in the Hot Springs Valley Bay area on Akutan Island is under way, with the idea to develop a 10-megawatt power plant in the highly volcanic area. Prior to this summer, two exploration wells were drilled, with additional field work ongoing this summer, according to Baldivieso, who categorizes the island's geothermal offerings as: "The classic surface expression of the resource, including hot springs and minerals." The island features an active hydrothermal system located only four miles away from the town of Akutan and includes more than 10 hot springs and considerable fumaroles, which are natural openings in the earth's crust that emit steam and gas.
Exploration wells were drilled this summer at the Pilgrim Hot Springs project, located some 35 miles north of Nome, according to Baldivieso. Exploration is under the leadership of the University of Alaska-Fairbanks's Center for Energy and Power. The Seward Peninsula project is located 80 miles south of the Arctic Circle and is accessible via a small landing strip. The geothermal features of the site include a "thaw zone" of warm soil and tree and brush foliage that stands out among the surrounding tundra. The springs and seeps that flow into the Pilgrim River range in temperature between 145 and 160 degrees Fahrenheit.
Mount Spurr, located 70 air miles from Anchorage and 33 miles from Tyonek, is considered the closest potential geothermal resource to the Railbelt, according to Baldivieso. "This is targeted as a large project," he says. Several seasons of field work and preliminary drilling have occurred, with additional field work planned again for this summer. That comes on the heels of press reports last year of disappointing results from 2011 summer drilling.
"They've explored a little bit ... and have shifted their target area over a little bit, and are determining whether they can go forward with some more exploration drilling," says Baldivieso.
The landscape itself is an active volcano with contemporary eruptions.
In presentations last year to lawmakers and energy industry leaders, officials from project developer Ormat Technologies Inc. summarized the project timeline so far, with state lands leased in October 2008, non-intrusive exploration conducted in 2009 and 2010, two exploration cores drilled in September 2010, and one deep core hold drilled in the summer of 2011. The 2009 and 2010 drilling samples suggested encouraging potential results, with evidence of geologic faults that could accommodate geothermal resources at depth--and with the potential, favorable high temperatures looked for by such projects. The 2011 deep core hole in the eastern region of the resource indicated cooler temperatures and a non-favorable rock type. However, according to the company, the geologic data still suggested possibilities of a commercial-level geothermal resource in the project's central region.
While the resource's location offers the benefit of being close to the Railbelt, such development of power production would require considerable transportation and transmission infrastructure. The original potential, according to the developer, is for an estimated 50 to 100 megawatt net production; and, at 95 percent availability, 416 to 832 gigawatt hours per year.
"We're really waiting for the results of this summer's field work," says Baldivieso.
Meanwhile, in Southeast, reconnaissance efforts are continuing to assess areas for potential development, according to Baldivieso. The Tenakee Inlet area near Sitka is among prime topics of ongoing discussion regarding geothermal resource.
"People know there is hot water down there," he says of the region's array of established thermal springs.
On the national and global front, geothermal industry developers and partners planned to convene in Nevada for an annual conference September 30 through October 3. The Geothermal Energy Expo--considered the world's largest gathering of the companies that provide services and products for geothermal resource exploration, development, production and management, according to the Geothermal Energy Association trade group--has in the past served a networking function for energy developers and buyers. A dozen countries, ranging south from Australia north to Iceland, had signed up to participate by press time. Hot topics for discussion this year include the future of energy tax credits for geothermal and political candidates' energy agendas.
Nicole Bonhom Colby writes from Ketchikan.
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|Comment:||Alaska geothermal power: Alaska energy authority overview of projects.(ENERGY)|
|Author:||Colby, Nicole A. Bonham|
|Publication:||Alaska Business Monthly|
|Date:||Oct 1, 2012|
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