After drilling several test holes at a hot springs near Nome, scientists and prospective developers of a planned geothermal electric project still haven’t found the energy they need. But they may be getting close.
A production-size hole -- big enough to be turned into a working geothermal power plant -- was drilled in September. It produced plenty of water, one of the requirements for a planned 2-megawatt power plant. But the water wasn’t quite hot enough. Two smaller holes were later drilled into the tundra at Pilgrim Hot Springs, 60 miles northeast of Nome, in mid-October to test for hotter water temperatures, but scientists aren’t sure yet if the site will produce fluid near 190 degrees Fahrenheit. That’s the threshold for a geothermal plant to produce enough energy at the site to make it a worthwhile endeavor.
Meanwhile, work is wrapping at Pilgrim Hot Springs for the winter. The drill rig is being torn down, as is the temporary camp used by workers.
Chena only operating geothermal power plant in state
But interest in the site is still smoldering. A coalition of Alaska Native corporations, local village groups and University of Alaska scientists have joined a private company, Pilgrim Hot Springs LLC, to determine if the area could bolster Nome’s growing renewable energy resources and help the Bering Sea community end its reliance on costly -- and sometimes difficult to obtain -- diesel fuel.
Pilgrim Hot Springs has been examined many times before, but there’s no commercial production yet. The issue: Is its hot water hot enough to support a commercial operation?
Chena Hot Springs -- an 80-room resort 580 miles east of Nome, near Fairbanks -- is the state’s only operating geothermal power plant. Steamy water there powers some 400 kilowatts of electricity, providing all of the resort’s needs. But Nome, with a population of 3,600, needs much more power. The Nome Joint Utility System needs at least 2 megawatts from the project to make it feasible and cost efficient. The first hole drilled in Spetember, yielded water temperatures of 165 degrees. That’s enough to power a small electric generator, but it would only produce enough energy to power on-site needs -- about 200 kilowatts -- but not enough to light the hundreds of homes and businesses in nearby Nome. Another test well shows greater promise.
“We are confident that the site could generate 2 megawatts of energy,” said Gwen Holdmann, director of UAF’s Center for Energy and Power, a partner in the Pilgrim Hot Springs project.
Holdmann said the new hole showed water temperatures of about 170 degrees Fahrenheit. She’s still looking over data from the new well test and expects water temperatures to increase once the well equalizes.
“When we drill a well, the mud and water from the surface get into the hole and cool the hot springs water, so the temperatures at the new well should be higher than initially indicated,” Holdmann said.
More testing will be done next summer. The hope is the site could add to the Nome area’s already-extensive renewable energy sources.
Two nearby turbine farms
Nome already has 3 megawatts of wind power from two turbine farms at nearby Banner Peak. But that’s not enough to handle peak demand for the city, which can reach 6.5 megawatts in the winter. And wind power is not guaranteed. If there is too little wind, or if it gusts too high, the turbines have to be shut down. Eighteen megawatts of diesel power handles most of the city’s electric generation. And that’s an expensive solution. The price of diesel -- barged to the city through the Bering Sea and purchased in bulk due to the huge quantities needed to keep the city going in the winter months -- climbed to more than $3.50 per gallon this year. As a result, the rate for electricity in Nome is 36 cents per kilowatt hour. By comparison, Anchorage residents pay just 14 cents per kilowatt hour.
The price of building a geothermal power plant at Pilgrim Hot Springs is estimated to be $10 million. Most of the expense associated with the project, however, will come in stringing up 60 miles of power lines from Pilgrim Hot Springs to Nome. That is estimated to cost about $500,000 per mile. Add it up, and the total project cost is estimated at $40 million.
If it works, Pilgrim Hot Springs could help bring down Nome’s electric costs.
Contact Sean Doogan at sean(at)alaskadispatch.com