A good case can be made that using the earth’s natural energy storing capabilities is the most cost efficient and environmentally friendly way to heat and cool homes, businesses and institutional buildings.
Geothermal systems draw on the earth’s relatively constant temperature to provide heating in the winter and cooling during warm months at operating costs that are substantially less than conventional systems with an ample supply of hot water as a bonus.
Basic components of a home geothermal system are an underground “loop” of HDPE pipe, indoor ground source heat pump (GHP) and a flow center to connect the loop to the heat pump. The system uses the earth’s relatively constant temperature to heat or cool the building, then recirculates fluid through the loop. Commercial installations may require multiple loops and heat pumps, depending on the size of the structure.
The loops of pipe are a critical component of a geothermal system and their installation can be the most time consuming part of the process. In a typical residential system, a vertical loop is placed in the hole drilled by a small water well drill. If space permits, horizontal loops can be installed by trenching or horizontal directional drilling. Other options are lake loops and open loops (see box for details).
Geothermal heating and cooling technology has been available for years, but the higher initial cost of an installed geothermal system compared to conventional air conditioning and heating systems, combined with the relatively low cost of natural gas and electricity, have been primary factors that have discouraged widespread use of geothermal systems.
However, that has changed in recent years.
Escalating energy costs make geothermal systems a serious option for property owners, and proponents of geothermal technology believe its time finally has arrived in North America.
“Interest in geothermal heating and cooling is growing rapidly – everything we hear is upbeat,” says Jim Bose, Ph.D., P.E, executive director of the International Ground Source Heat Pump Association (IGSHPA). “Ground source heat pump systems finally are mainstream and are capturing a growing share of the market.”
Bose became involved early in development of geothermal heating and cooling technology, and was involved in the first installation at an Oklahoma State University laboratory. He has been a proponent ever since.
“I thought I had discovered a technology that would change the way buildings would be heated and cooled,” recalled Bose. “A system that could deliver 30 percent savings in operating costs year after year was very attractive.”
However, relatively low fuel costs made it difficult to justify the higher cost of a geothermal system.
“Thirty percent savings is not very much,” Bose continued. “Therefore, many considered the pay back for investing in a geothermal system as too long to justify the cost of a ground source heat pump system.”
Bose said the turning point came three or four years ago when natural gas prices peaked.
“That brought attention and interest to the benefits of geothermal systems,” he said. “Thirty percent savings of high heating and cooling bills is significant, and even though there are price fluctuations from year to year, most people believe the cost of natural gas will continue to increase.”
Over the years of no growth and slow growth, manufacturers perfected ground source heat pump products, and the number of contractors proficient in installation and servicing geothermal systems has increased.
“We are past the day when prospective buyers wanted to see results of demonstrations that proved the systems work,” observes Bose.
Emergence of environmental awareness also is a factor that favors geothermal heating and cooling which is being effectively marketed as a green product that operates on renewable energy. On average, a home ground source heat pump system reduces carbon emissions four metric tons per year.
A report published in December 2008 by the Oak Ridge National Laboratory estimates that aggressive deployment of ground source heat pumps could achieve 35 to 40 percent of a recommended carbon reduction path for the U.S. building sector.
Finally, with available tax credits, low interest loans offered through many electrical utilities, and now stimulus incentives, it is a good time to consider switching to geothermal heating and cooling.
Said the Oak Ridge report: “Today’s domestic GHP industry is better positioned for rapid growth than ever before. The technology is proven, with an installed base in the United States exceeding 600,000 GHP units. Tax credits for home and business owners investing in GHP systems were enacted in October 2008 through 2016.”
Awareness of the benefits of geothermal certainly is increasing,” said Evie Sibert, marketing communications manager of ClimateMaster Inc., Oklahoma City, which identifies itself as the world’s largest manufacturer of geothermal heating and cooling systems.
“Currently,” Sibert continued, “residential is up while commercial is down, and industrial remains constant. We also are seeing an increase in the retrofit business. Geothermal moved forward during 2008 when the energy costs were high. Now, tax incentives have a major influence on the industry. As energy costs increase over time, so will the demand of geothermal.”
From the mid-1980s through the ’90s, demand for ground source heat pump systems did not justify specialist contractors, and progressive plumbing/heating/cooling business owners probably were first to recognize the potential of geothermal technology.
However, few were equipped to install loops; vertical drills are expensive and compact trenchers often owned by plumbers cannot dig to sufficient depths for horizontal loops. Depending on system requirements, backhoes could dig to needed depths, but digging hundreds of feet of trench with a backhoe can be slow work.
Loop work often was subcontracted to water well drillers or excavation contractors. Larger trenchers were available from equipment rental stores, but to use directional drilling meant subcontracting to a specialist.
No statistics are available about the types of loops installed, but most are horizontal or vertical as dictated by conditions and sometimes by the preference of the contractor.
Because many early systems were for residences without sufficient space for a horizontal loop, many were vertical loop systems.
Today, there are contractors who specialize in geothermal systems, and some heating and cooling contractors have established specialized divisions to sell and install ground source heat pump systems.
Comfortworks in Goldsby, OK, sells, installs and services geothermal systems. The company evolved from a heating and air conditioning company established in 1975 to a business today that offers turnkey geothermal system sales and service in the Oklahoma City metropolitan area and other portions of the state.
“Most loops we do are vertical loops installed by our own crews with our drilling equipment,” said President Chris Ellis. “We like vertical loops because we are equipped to do them. Second would be pond loops, and third horizontal loops. We trench those; we do not use directional drilling.”
Ellis said demand for geothermal systems in his area is increasing.
Demand in the mountains
Rocky Mountain Geo Thermal Inc., Denver, CO, was established in 2003 to serve the growing demand for geothermal systems.
“We looked at the market and concluded geothermal systems are the future of heating and cooling,” said Vice President Jim Lynch. “We made the commitment to conduct the business professionally and that has been the key to your success. Growth has been steady and consistent.”
To meet growing demand, the company established Rocky Mountain Geo Drill Inc. specializing in drilling, looping and grouting, said Lynch. In 2006 a further expansion added Geo Energy Services providing system design and engineering to establish the company as a complete design/build contractor offering turnkey services.
The majority of the company’s projects have vertical loops, said Lynch, with about 30 percent with horizontal or pit loops.
“Required heating and cooling loads dictate the size of the loop field,” said Lynch. “The site size and constraints dictate whether we have to drill vertically or if there is enough area we can install a horizontal loop field. Typically we drill vertically.”
To date, the company has completed more than 400 geothermal loop field projects in Colorado, Wyoming, Montana, Utah and Nebraska. Many are large commercial projects. Expansion into Arizona and New Mexico is planned, Lynch said.
As 2009 winds down, business is good.
“After a relatively slow first two quarters,” Lynch said, “the commercial geothermal industry is growing at a significant rate. New housing starts are still slow but the commercial projects are picking up at a good pace. Because Rocky Mountain Geo Thermal is the largest and most reputable geothermal contractor in the Rocky Mountain region with an excellent reputation, we complete the majority of the projects in the area.”
In Moline, IL, QC Geothermal finds strong demand for geothermal systems in the Quad Cities area and other areas in Iowa and Illinois.
QC President Bruce Soukup said the company was in the heating/cooling business before it expanded into the geothermal market. For its first ground source heat pump job, a rented trencher was used to put a horizontal loop in the ground.
“We discovered an opportunity and developed a niche in the geothermal market,” said Soukup. “The number of installations we do has increased each year, as energy costs became a greater concern, the more installations we did.”
Soukup made the decision to invest in equipment to install loops rather than only sell and install system components.
“We started with one vertical drill and then added a horizontal directional drill in 2001,” said Soukup. “We maintained a steady workload of residential geothermal work, and then began taking on commercial projects.”
Soukup believes the experience of completing residential systems helped make the transition to large and more profitable commercial projects.
“Currently our geothermal workload is about 20 percent residential, 80 percent commercial,” he said. “For commercial jobs, QC may turnkey a complete project; or on other projects subcontracts installation of the loops.
With increased commercial geothermal business, Soukup added another vertical drill and a new, larger directional drill.
The HDD installation process permits the loop to be installed under: driveways and walks; lawns, flower beds and other landscaping; outbuildings and other surface obstructions. Excavation is minimized which reduces restoration costs.
“Over the last three years, our use of directional drilling for commercial loops has greatly increased,” said Soukup. “The increased demand justified the investment in a new larger drill unit that increased production capabilities.”
With geothermal’s popularity growing and the economy down, some HDD contractors may be looking to that market for work.
“We are seeing some HDD specialists interested in loop work,” said Soukup. “But we are well established, and some engineers now require a contractor be pre qualified to be considered for a geothermal project, and that gives us an advantage over drillers from other markets.”
The future for geothermal heating and cooling appears to be extremely positive.
Rocky Mountain Geo Thermal’s Lynch said higher up front cost of a geothermal system is about the only negative his company encounters. But that factor is being offset by rising fuel costs, a 30 percent tax credit and 10 percent rebate on a complete system.
“A pay back or ROI in the three to seven year range makes sense to owners,” he added. “And the build green movement seems to be helping, also.”
Despite the bright future predicted for growth of geothermal heating and cooling in the United States, barriers remain.
Perhaps the best recent analysis of the status of the geothermal market in the U.S. is the Oak Ridge National Laboratory report Geothermal (Ground Source Heat Pumps) Market Status, Barriers to Adoption, and Actions to Overcome Barriers, released in December 2008.
Key barriers to growth cited in the study are high first cost of GHP systems, lack of consumer knowledge and/or confidence in GHP system benefits, lack of policy maker and regulator knowledge of and/or confidence in of benefits of GHP systems, limitations of GHP design and business planning infrastructure, limitations of the number of trained GHP system installer personnel, and lack of new technologies and techniques to improve GHP system cost and performance.
However, the report’s conclusions about the future of the industry are positive and include the following:
“Every building in America sits on the ground, and the ground is generally cooler than outdoor air in summer and warmer in winter. GHPs use the only renewable energy resource that is available at every building’s point of use, on demand, cannot be depleted (assuming proper design), and is potentially affordable in all 50 states. GHPs may be among the most affordable renewable energy resource, especially considering the investments in electrical transmission that will be necessary to deliver many of the best wind, solar, and geothermal power generation resources to market.
“Today’s domestic GHP industry is better positioned for rapid growth than ever before. Not only has the industry grown with the help of past federal and utility programs, but it has proven that it can stabilize and grow on its own again when such programs disappear. Compared to the early days, the diverse segments of the industry are better able to work with each other as a cohesive whole. The United States has the world’s largest installed base of GHP systems, which can be mined for statistically valid hard data on costs and benefits, as well as best practices.”
The Oak Ridge National Laboratory is managed by UT Battelle for the U.S. Department of Energy. The geothermal report was sponsored by the EERE Geothermal Technologies Program, U.S. Department of Energy.
FOR MORE INFORMATION:
International Ground Source Heat Pump Association, (405) 744-5175, www.igshpa.okstate.edu