Geothermal energy use gaining steam in the U.S.
By Jennifer Keefe Sunday, October 17, 2010
Editor's note: This is the first in a series examining the state of the alternative energy industry.
DOVER — New Hampshire's White Mountain range eventually could be the site of a geothermal power plant, although research is just in the beginning stages.
A Department of Energy grant for $22 million awarded earlier this year to the Association of American State Geologists is funding research around the country to determine the best sites to use geothermal energy. New Hampshire, which will see about $300,000 of that grant, has geothermal potential in the northern part of the state, according to State Geologist David Wunsch.
To understand the possibility of a geothermal power plant in the Granite State, it is important to first understand how a geothermal system of this magnitude would work.
Geothermal means, as the name implies, heat from the Earth. A well that could measure 3,000 feet deep or more would be drilled, and water would be pumped into it. As the water passes through the well and over the rock, it would be heated by the Earth — at about 150 degrees Celsius or 302 degrees Fahrenheit — creating steam that would in turn run a power plant.
A power plant would use very large pipes, Wunsch said, and the project could cost "tens of thousands of dollars." As it is still an idea in the works, the exact cost and scope of the system, and it's performance, are unknowns.
He said the first studies into geothermal capabilities in the state occurred in 1978 in the Conway area's granite rock. It was funded by a grant from the Department of Energy.
"They drilled a deep hole, 3,000 feet deep, to see how hot it was up north near Conway," Wunsch said. "They didn't find the temperatures they had hoped for. That was last real search for geothermal in the state."
The search "remained dormant," Wunsch said, until federal stimulus money became available. Now, they are able to reopen the search for geothermal energy.
While new research has only just begun for a geothermal use of this size, smaller-scale geothermal heating systems for homes and businesses are gaining popularity around the state.
Donald Gagnon built his Kittery Point, Maine, home to be as energy-efficient as possible. With the installation of solar panels and heat-saving insulation, it wasn't a question in his mind that he'd use a geothermal system to heat and cool his home. Roe Cole with Roe Cole Custom Design and Construction in Kittery installed a closed-loop geothermal forced-air system.
With a tall, tubular tank and a few other components in his basement, including a heat exchanger, Gagnon is able to draw water at about 50 gallons per minute from a 340-foot deep well, which absorbs heat from the ground. An electric heat pump extracts the heat from the water. The cold water is then recirculated through the ground in the same cycle.
The heat extracted from the water heats Gagnon's home. This type of system overall generates more heat than an electric system because of the ground circulation.
Gagnon can also achieve air conditioning in his home by switching the direction of heat flow.
Even though the heat exchanger runs on electricity, Gagnon said he is able to offset much of his electric costs with his solar panels.
Since Gagnon and his wife moved in to the newly-built home in November, he's been enthusiastic about the results of their energy-saving components.
"The savings at this point are adding up now that we've had a full-year cycle," he said. "We're starting to basically see the savings. Our electrical bill is pretty steady. We're not seeing these huge oil bills in the winter."
Cole agreed the system "exceeded" what he thought it was going to do, but stressed geothermal will really only be cost-effective if the home is insulated properly to prevent heat loss through walls and windows.
A home system such as Gagnon's may cost anywhere from $15,000 to $40,000, depending on the size of the home, according to Guy Marshall, general manager of Lamprey Brothers, which has installed geothermal systems in several homes.
Melissa Aho, president of Ultra Geothermal in Barrington, said geothermal heating systems are becoming more widespread for homes and some apartment or commercial-use buildings, and much of the reason is rising oil costs.
"It's been a huge growing business for five years now," she said. "The technology has been around since 1935 and been installed viably for 40-50 years. When fuel costs went to $4 per gallon, people were trying to figure out any way not to have to pay that type of heating bill. That was a booming era we went through. We did 250 (geothermal systems) in one year."
Larger-scale projects in the Seacoast and surrounding areas include four two-unit apartment buildings in Epping, elderly housing in Manchester and a jail in Grafton for the Grafton County Department of Corrections. Those projects were completed by Denron Plumbing and HVAC in Manchester.
Denron Estimator Joel Pickering said installing a geothermal system in a commercial-use building really makes sense for a long-term owner because the energy savings over time will pay off the up-front cost.
The University of New Hampshire recently saw the completion of the River's Edge apartments, which run on a geothermal system. The project was completed by Northam Builders of Dover.
Jeff White, owner of Northam Builders, said the system is basically a larger-scale home system. The apartment building uses four wells drilled 1,200 feet deep and can pump anywhere from five to 60 gallons of water per minute depending on the need.
Like Gagnon's system, the water also can be used to create air conditioning in the summer.
"It brings water in at whatever temperature the well is at," White explained. "If the well is at 55 degrees, the water is brought in at 55 degrees. In cooling mode, it takes the cool out of the water and uses that cool to convert into cold air for AC. For heat, it takes the heat out of the water and converts it to hot air."
White projects the payback period on the system to be about six years, but said that time will be shorter if oil prices continue to increase.
Aho, with Ultra Geothermal, said it is important to find a builder who knows how the technology truly works.
Robert Hayward retrofitted his oil heat system with a geothermal system in his Dover home for $30,000 in the fall of 2008. He said the cost benefits are already apparent.
"We are able to save about half on our energy costs," he said. "About 50-60 percent. That's a savings of about $2,000 per year on our energy costs."
Hayward admitted the up-front costs can be prohibitive, which is why it's more efficient to install a geothermal system when building new. He estimated it would take 10 to 15 years to pay off the installation costs in his home.
Geologist Wunsch said they will continue to collect data from all over the state with the intent of providing information to companies looking to invest in geothermal energy.
"We're collecting the kind of data a company will need to evaluate the potential of geothermal energy before they invest the money," he said. "They talk about it, but when they start digging in, they find they don't have all the information."
He explained there are several types of geothermal systems. The one being discussed for New Hampshire and used in homes is called Direct Heat. Another, which is mainly used out West and creates electricity that runs off steam, is called hydrothermal.
Wunsch said there are some risks to using a geothermal system, which include the possibility of small earthquakes due to water running against the rock in a deep well, and the chance of radioactive materials coming up with the recirculated water. The state will be collecting data for both possibilities before any serious undertaking.
Aside from those possibilities, Wunsch highlighted one of the unique qualities of geothermal energy.
"Of all the different forms of green energy, geothermal is the only one that produces base power, which means it produces 24/7," he said. "It's constantly generating electricity. This is something we need because even if you create wind power, it would go dead at some point" when the wind stops.
He said it was too soon to know the financial scope of the project, especially in terms of how many years it would take for the savings to pay off.
"We're at the very forefront of this whole energy horizon," he said.
EJ Hersom/Staff photographer Donald Gagnon points to a thermometer in his Kittery Point, Maine, home. Gagnon pays almost nothing for utility bills with geothermal and solar systems.
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EJ Hersom/Staff photographer Homeowner Donald Gagnon explains how he has reduced his utility bills to almost nothing with his geothermal and solar system in Kittery Point, Maine.
Click here to view Foster's prints for sale
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