BY ERIN CAMPBELL
Later this spring, we’ll see farmers out in the fields digging into the earth to plant crops. The ground beneath us has incredible benefits. In fact, you can also harness the power of the earth to heat and cool your home renewably and efficiently.
Geothermal heating and cooling systems – also referred to as ground source heat pumps – use underground loops to take advantage of the constant temperature below ground to keep you comfortable. In the winter, the loop system removes heat from the ground and transfers it into your living space. In the summer, the loop system transfers warm energy from your home to be absorbed by the cooler ground.
A proven technology
Geothermal technology isn’t new; in fact, Iowa’s electric cooperatives have been promoting geothermal systems to members since the 1980s. Jim Sayers was one of those co-op employees who worked to educate members about the many benefits of geothermal throughout his 34-year career in communications and energy services at Corn Belt Power Cooperative. Headquartered in Humboldt, Corn Belt Power Cooperative is a generation and transmission electric cooperative owned by its member systems.
Sayers retired from the co-op in 2018 and found an opportunity to continue educating others about geothermal technology’s advantages as the cooperative engagement coordinator for the Geothermal Exchange Organization (GEO).
“You retire from a job, but you don’t retire from your passion. And my passion includes Iowa’s electric cooperatives and geothermal,” says Sayers.
Efficient, renewable energy
Geothermal systems are supremely efficient, renewable and will save homeowners substantially on heating and cooling costs, according to Sayers. The average savings of geothermal compared to an aging conventional HVAC system is around $1,400 annually, accounting for 40%-70% savings. And while the installation cost of a geothermal system is higher than conventional HVAC systems, it is so efficient that it can pay for itself in as little as five to seven years. Rates and incentives are important in determining payback.
“The good news is that there are federal and state tax credits available to help defray the installation costs,” says Sayers. “Currently, the federal tax credit for geothermal installation is 26%, and the Iowa tax credit is 20% of the federal credit, for a total tax credit of just over 31% of the geothermal installation cost in 2021.”
So why is the installation of a geothermal system higher than installing a conventional HVAC system? It comes down to the loops. An underground loop system needs to be trenched or drilled in your yard to take advantage of the earth’s constant temperature. Once installed, a water-based solution circulates through the loop system to transfer the heat energy. Electricity is needed to operate the heat pump, ground loop pump and distribution fan or pump.
Because it uses the earth, a geothermal system is the most efficient heating and cooling system. In fact, it is 400% more efficient than conventional HVAC systems. Geothermal systems are also known for having low maintenance costs.
Sayers says, “With all the attention on wind and solar these days, we often forget about geothermal as a renewable option. If a homeowner is considering investing in a solar array, I would encourage them to first think about energy efficiency measures and then consider installing a geothermal heating and cooling system because it uses stored, renewable thermal energy all day, every day, year-round.”
Resources for more information
The cost of installing a geothermal system will vary by location, the size of your home, equipment installed and local incentives. GEO, a non-profit trade association that promotes the manufacture, design and installation of geothermal heating and cooling systems, maintains a list of geothermal system professionals you can contact at www.geoexchange.org/directory/.
Learn more about geothermal at GEO’s consumer education website at www.geothermalforall.com. In addition to the tax credits, many of Iowa’s electric cooperatives offer special geothermal electric rates and incentives to make the system even more affordable. Contact the member services staff at your co-op to learn more.
Erin Campbell is the director of communications for the Iowa Association of Electric Cooperatives.
1. Ground loop. The earth absorbs and stores almost 50% of the sun’s solar energy. Because of this, the temperature four to six feet below ground is consistently between 45-70 degrees F. A geothermal system transfers heat from one place to another using a ground loop field buried in the yard. The loop field circulates a water-based solution through a series of pipes.
2. Flow center. The flow center resides on your unit or a wall near the geothermal system. It pumps the water-based solution in the ground loop to the house or building unit to disperse heating or cooling.
3. Indoor heat pump. The loop field transfers heat to the home through an indoor geothermal heat pump kept indoors through forced air and radiant heating and cooling.
4. Forced-air heating and cooling. In a forced-air system, an air-handler disperses the ground’s heat to air in a home or building through ductwork and vents. In the cooling mode, the process is simply reversed.
5. Radiant heating (optional). Known as the most comfortable type of heating, radiant heating uses a series of pipes under a home or building’s floor to circulate warm water, which heats the entire space evenly.
6. Hot water. A hot water assist, known as a desuperheater, allows the system to capture excess heat to assist a water heater. This cuts hot water costs 25-40%. Geothermal systems can also provide 100% of the hot water needed for a home.
Graphic courtesy of Enertech Global.