Unalaska seeks drilling company for geothermal project

The City of Unalaska is seeking proposals for geothermal drilling services as part of the city’s initiative to develop a geothermal power source close to the Makushin Volcano on Unalaska Island in Alaska.

There is a known geothermal source accessible by drilling from a bench feature at an elevation of 1,200 feet on the side of the volcano. But difficulty of access to that site has led the city to seek a source on the valley floor next to the volcano, at an elevation of 400 feet.

In June 2007 Unalaska City Manager Chris Hladick told Petroleum News that the geothermal investigation would likely involve drilling 2.5-inch, slim-hole wells in the valley floor. The investigation would lead to a decision regarding whether the geothermal power plant should be located on the valley floor or at the original bench site, he said.

The city’s request for drilling proposals says that the valley floor investigation will entail the drilling of three temperature-gradient wells to a maximum depth of 1,000 feet.

In harnessing energy from the Makushin Volcano, the city hopes to take advantage of state-of-the-art geothermal technology that enables power generation from a relatively low-temperature geothermal source. A pioneering geothermal plant at Chena Hot Springs in Alaska’s Interior has already successful demonstrated this type of technology.

The City of Unalaska also hopes to pipe hot water from the Makushin geothermal facility into town to heat buildings.

The geothermal power plant would replace diesel generators for the supply of base load electricity for Unalaska. Diesel generators would still be required to meet peak load, Hladick told Petroleum News in 2005.

—Alan Bailey