Geothermal energy reduces costs environmentally and economically
On her 25th year in her Linden Hills home, Nina Utne finally accomplished her mission of finding a way to heat her large home in an environmentally friendly way.
Her concerns of overdependence on natural gas and oil were relieved with geothermal power — a method that only relies on the earth’s temperature underground.
“My sense was that gas and oil prices were just going to keep going up,” Utne said. “It was a prudent investment that I hope eventually everyone makes.”
For these same reasons, other Southwest residents have joined Utne by switching to geothermal power to reduce cost both economically, and more significantly, environmentally.
Geothermal power uses the constant, cool temperature of the earth’s subsurface to heat homes by reducing the reliance on methods that call for more demand of Earth’s ecosystems.
In his second year of installing geothermal systems, Josh Savage, owner of Ridler’s Uptown Heating, Cooling and Renewable Energy, said the process of heating homes relies on a fluid circulating through wells that dive 180 feet below earth where the temperature is a constant 47 degrees.
After circulating through the wells, Savage said the fluid enters the home cooled to 47 degrees due to exchanging heat with the subsurface throughout circulation. The fluid then goes through a heat pump that extracts even more heat from the fluid and converts it to hot air that heats the house, he said.
Cooling a home during the hot, summer months relies on a much less complicated method, according to Savage, who said the system reverses the heating process, which results in hot air being extracted from the house and returned to the subsurface of earth.
“The earth becomes a huge savings account where we store energy until we need it later on,” Savage said.
He said the expense to the ecosystem from burning fossil fuels to heat or cool a home is replaced with utilizing the earth to save energy.
Economically, it is a savings account with high returns.
To power the heat pump, electricity is still required, but with one dollar of electricity producing three to five units of energy, Savage said geothermal typically cuts heating and cooling costs in half.
“Imagine a cash machine that would spit three dollars out for every dollar you put in,” Savage said. “You would just keep putting dollars into it.”
Louise Goldberg, program director for the Energy Systems Design program at the University of Minnesota, said the process of geothermal heating and cooling is no different than a wall air conditioner with the one exception that geothermal systems exchange heat with the ground rather than outside your home.
Goldberg said the constant low temperature of the ground compared to the fluctuating extremes of outside temperatures is what makes the geothermal heat pump much more energy efficient and reduces reliance on electricity.
When Mike Rosenman was deciding on how he wanted to heat and cool his recently purchased Lowry Hills home, geothermal was not his first choice, but the economic benefit of little to no natural gas bills and reduced electricity convinced him to forgo a more conventional method.
“There is obviously a little more out of pocket from day one, but the payback period with incentives is just phenomenal,” Rosenman said. “It was just a no-brainer anyway you look at it.
Although the long-term economic impact of geothermal power is enticing, Savage said initial costs are around $30,000 for the drilling of the wells and the installation of the heat pump.
The majority of the installation cost is attributed to the drilling of wells straight into the ground, said Goldberg, who noted the vertical method is the most expensive way to install the wells.
But he said there is no other way to drill at a residential home where space is at a premium.
Currently, there are federal tax breaks to ease upfront costs, but the payback period with the reduced monthly cost is still around 15 years, Savage said.
Because of this, Savage said reducing damage to Earth’s ecosystem has to be as much of a driving force as reducing the monthly utility bill.
“Your primary reason for wanting it has to be environmentally motivated, and the icing on the cake is the financial incentives that are currently available,” Savage said.
For Utne, the switch to geothermal meant a number of different payouts. Besides environmental and economic benefits, she said she also received a heating and cooling system that regulates her house’s temperature better than ever.
“I can leave the window open for fresh air and leave it on,” said Utne, who is experiencing her first summer with air conditioning. “The system is so energy-efficient that it does not matter if some cold air leaves.”
During the winter months, a geothermal system requires a backup heating source when outdoor temperatures are around 5 degrees and lower, Savage said. This is usually accomplished with the home’s past heating source.
Rosenman said geothermal had little trouble making his home as comfortable without any help from his old, natural gas system during his first winter.
“Most of the winter the radiators were cold, which is always a pretty good sign that you are rarely using any gas,” he said.
Geothermal’s popularity among homeowners is rapidly increasing, according to Savage, who said Ridler’s Uptown Heating, Cooling and Renewable Energy had already installed 13 geothermal units since it started last year and expects to install 23 more this year.
At the University of Minnesota, Goldberg said researchers are looking to make geothermal become the standard for heating and cooling by developing technology that reduces the first cost of installing the system.
Goldberg said she is part of a team of researchers acquiring funding to test a geothermal system that utilizes groundwater with the potential to heat nine blocks of homes with one installed system. It has the potential to reduce start-up costs by 90 percent for homeowners.
“By cutting the first cost and improving the technology, we are talking potentially, very serious changes,” Goldberg said.
Martin Saar, professor of earth science, geology and geophysics at the University of Minnesota, said geothermal is the most stable way to heat and cool a home, and more widespread use can only be beneficial to everybody.
“You don’t have to worry about security in supply, where it is from or how much longer can we use it,” Saar said. “Environmentally, geothermal could make a huge difference.”