Contractors, developers, and equipment manufacturers are seeing growing opportunities for residential geothermal projects in the U.S.
As of 2023, according to the U.S. Department of Energy (DOE), approximately 3% of the homes in the country were equipped with ground-source heat pumps. But some in the geothermal industry, noticing strong interest in residential geothermal in parts of the country, say that proportion is set to increase, and they want to be a part of making that happen.
“There’s an exciting market developing in the U.S., and we’re wanting to take what we’ve known, what we’ve learned, from our experience here in the U.K. and broaden that into a developing market in the U.S.,” said Kevin Stickney, managing director of Erda Energy Ltd., which operates in the United Kingdom but is looking to expand into the U.S. and is owned by a Texas-based firm.
“There has been an increase in customer demand for single-family GSHP (ground-source heat pumps),” said Joe Parsons, senior marketing sustainability manager at the Climate Control Group, parent company of ClimateMaster Inc., which makes geothermal equipment.
Erda Energy is focused on the decarbonization benefits of large-scale geothermal systems. Stickney sees environmental concerns as fueling the interest in residential geothermal in the U.S.
“You’ve got some areas where you’ve got a lot of social desire to change,” Stickney said. “You’ve got some areas where there are genuinely green grids going, and a lot of green electricity. You’ve got a great climate in a lot of places where you’ve got that balance seasonally between heating and cooling.”
Parsons said consumer awareness of geothermal is increasing due to efforts by manufacturers and groups such as the International Ground Source Heat Pump Association (IGSHPA) and the Geothermal Exchange Organization. Incentives have made geothermal more attractive financially, he said, and there is more interest in geothermal communities, such as Norton Commons in the Louisville, Kentucky, area. Every new home in Norton Commons is heated and cooled by a ground-source heat pump.
VERSATILITY: A ClimateMaster Tranquility SJ heat pump. ClimateMaster heat pumps can be used as either water-source or ground-source heat pumps. (Courtesy of Climate Control Group)
In addition, Parsons said, “We are beginning to see buy-in from general contractors who are finding their properties have increased value and are more attractive to buyers based on the lower cost of (geothermal) operation and maintenance.” High mortgage rates make the lower cost of operation of residential geothermal systems more attractive, he added.
Clay Doyle, president of Geothermal Solutions, a geothermal installation and maintenance contractor operating in the Mobile, Alabama, area, has been working in geothermal since 2008.
“When I first started, I would get in front of people any way I could. I would work home shows, work gardening shows, have a tent at Earth Day events, present to clubs such as the Sierra Club, and meet with architects,” Doyle said. “At most all of these events, it was more of educating people than getting good leads.”
Doyle, whose company uses geothermal products from WaterFurnace International Inc., said he now sees a growing residential geothermal market, and he makes his pitches mainly to architects.
“I have seen growth, and most of it is from referrals or architects selling the homeowner on it,” he said. “Most architects like it because of the lack of outdoor equipment.”
When he does speak to homeowners, Doyle said, he stresses the long-term energy cost savings of geothermal. “If I’m speaking with a ‘green’ homeowner, I will get more into the less energy usage, as opposed to the dollars and cents of it,” he said.
Erda Energy, named for Norse mythology’s goddess of the Earth, did its first geothermal project in a supermarket in 2010. It has since moved on to larger residential, commercial, and mixed-use projects.
– Kevin Stickney
managing director
Erda Energy Ltd.
Erda uses borehole technological know-how from the oil and gas industry, and either contracts with manufacturers to make equipment to its specifications or uses products off the shelf from companies like WaterFurnace, Trane, and Carrier, Stickney said.
Erda’s work focuses on areas of high energy use, such as an ongoing project in Newbury, a town west of London, where a shopping center is to be replaced by a mixed-use urban development of shops, restaurants, a fitness center, a cinema, and more than 300 homes, from studios to three-bedroom units. It’s an effort to revitalize the center of the city.
“Obviously, you’re spreading the scale, you’re spreading the cost, you’re making use of the diversity in demand across different houses, so not everybody has their heating on at the same temperature and at the same time as each other, so you’ve got economies of scale,” Stickney said.
Erda is also consulting on another district geothermal project in development, in Cornwall, that he said would be comparable to installing geothermal in an existing U.S. subdivision.
“A group of householders, community getting together, you know — trying to get some community action going,” he said. “They’re looking to serve the school, they’re looking to serve local shops, all of the existing developments,” Stickney said. “We’re in the early days of helping them to plan that transition.”
Stickney said that although new residential geothermal projects on undeveloped parcels are easier to do, because there are fewer space constraints and no existing HVAC systems to integrate, replacing more traditional systems with geothermal is critical if society is to realize geothermal’s full decarbonization benefits.
“If you only attack new buildings, then you are not going to scratch the surface of the decarbonization problem, because the vast majority, 95% of our building stock, anywhere you look, already exists,” he said.
RESIDENTIAL PRODUCT: A ClimateMaster Tranquility 30 SE two-stage residential heat pump with a vertical upflow configuration. (Courtesy of Climate Control Group)
Parsons, at the Climate Control Group, said his company is seeing the most interest in its single-family geothermal products in the Northeast and in the middle of the country, from Minnesota to Texas.
“Contributing factors include the availability of the workforce in areas where (ground-source heat pump) adoption has historically been stronger, stronger state and local incentives, and states that have already substantially invested in meeting their long-term decarbonization target goals,” Parsons said. He also credited volunteers at various geothermal organizations.
For residential geothermal, ClimateMaster offers the Tranquility SZ two-stage heat pump, in capacities between 2 tons and 5 tons.
The Tranquility 24 SZ uses R-454B refrigerant, has a Copeland two-stage compressor, and offers part-load operation to lower yearly operating costs. The average EER is 19, and the average coefficient of performance (COP) is 4.0, said Caleb Fox, director of product management at ClimateMaster.
“With eco-friendly refrigerant and advanced features such as variable-speed motors and Energy Star certification, it ensures optimal performance and energy savings,” Fox said.
There’s also the Tranquility 30 SE two-stage heat pump, available in capacities of 2 tons to 6 tons.
The Tranquility 30 SE also uses R-454B, has a variable-speed blower motor, a double-isolated compressor mounting system for reduced noise, and a microprocessor-based control system for increased efficiency. The Tranquility 30 SE is rated at an average EER of 17.25 and an average COP of 3.67, Fox said.
“Featuring innovative vFlow technology” for optimized water flow “and Energy Star certification, this series accommodates a range of sizes and is designed for both new and retrofit installations, Fox said.
Both models exceed ASHRAE 90.1 efficiency standards, are for forced-air HVAC systems, and can be used as ground-source or air-source heat pumps.