More homeowners using geothermal energy systems

Journal Record, The (Oklahoma City), Jun 18, 2002 by Ray Carter

The official start of summer is just around the bend, and with it comes the threat of high temperatures and even higher energy bills. But for a growing percentage of homeowners, those bills won't be as staggering thanks to their use of geothermal heating and cooling systems. "I have it in my new home and it's unbelievable," said Jim Bose, professor of engineering technology at Oklahoma State University.

"I pay more to have my yard mowed than I do for energy. It's just that much better." Van Bourn, vice president of marketing and e-business for ClimateMaster, an Oklahoma City company that makes geothermal systems, said geothermal energy has been a viable power source since the 1980s, but a lack of public awareness has prevented its widespread acceptance. A typical 1,800-square- foot house could achieve energy cost savings of $80 to $90 per month if built with a geothermal system instead of a standard gas-fired system, and the increased cost of construction would amount to only $40 per month extra on a mortgage, Bourn said. "It's a real shame when you see those kind of missed opportunities," he said. Although many consumers think of geothermal energy as a technology that requires extreme conditions, such as the presence of hot spring, officials said the technology can be used almost anywhere. "We've got countries like Switzerland who have the largest number of installations per capita of any other country in the world, and this is (in) a very cold climate," Bose said. The earth absorbs nearly 50 percent of all solar energy and remains at a temperature of 50 to 70 degrees Fahrenheit. Using an underground loop system, geothermal heating and cooling systems harness that constant temperature to exchange energy between a home and the earth as needed for heating and cooling. In the winter, water circulating inside a sealed underground loop system absorbs heat from the earth and carries it to the geothermal unit. From there, the heat is compressed to a higher temperature and sent as warm air to the indoor system for circulation throughout a home. In the summer, the system reverses the process and expels heat from the home into the cooler earth via the loop system. One of the biggest challenges involved with using a geothermal system is finding space for the loop system, which can run as long as 900 feet. Horizontal loops can be installed at homes located on a large piece of property. Several hundred feet of trenches, running about five feet deep, are required for horizontal loop installation. Vertical loops are more common on property with limited space surrounding a home. To install vertical loops, officials must bore holes that average between 150 and 250 feet deep. The holes are then backfilled with a special grout solution to ensure good contact with the earth. However, modern drilling technology allows officials to install the loop systems with minimal damage to topsoil. "These holes can be punched alongside of the driveway," Bose said. "Sod is lifted up and the soil is compacted back and the sod is put down and there's a good chance in two or three days you wouldn't even know they've been there." The loops can last anywhere from 50 to 100 years, Bourn said, and many companies provide warranties of up to 50 years for the loops. Because the loops are made with materials that can stretch and adapt to changing conditions, normal underground shifting does not harm the loops. Although use of geothermal energy is not yet widespread, Bose said the industry is growing 25 to 30 percent a year. Large commercial buildings and schools account for much of the current demand for geothermal systems, Bose said. More than 600 schools nationally now have geothermal heat pumps. Most of those schools are not new buildings and are instead replacing old heat pumps with geothermal models and experiencing energy cost savings of 39 to 60 percent, Bose said. However, in the residential market, the majority of homes with geothermal systems were originally built with the systems, according to Bourn. Due to technical challenges, retrofitting the heat/air system of an existing home with a geothermal system can be challenging, he said, and retrofits account for only 15 to 20 percent of the market. The average cost of a home retrofit is $5,000 and financing has been the biggest obstacle for most people, Bourn said. If the system is installed as a home is built, the cost is included in the 30-year mortgage. But with a retrofitted system, most people have to repay the loan within three to five years. Bourn said Climate Masters is exploring new financing options to increase the appeal of geothermal retrofits. In addition, he noted that most traditional heat/air systems cost around $2,500 to fix or replace when they break down, so the expense of retrofitting a home for geothermal may not be as daunting as many people believe. He said a retrofit takes only two days to perform. Although most consumers purchase geothermal systems for the expected cost savings, the comfort level provided keeps those customers satisfied, Bourn said. The systems tend to keep temperatures very constant with little background noise. "They are more comfortable than any system out there," he said. With traditional heating and cooling systems, however, people are often aware that the system "needs to kick on" because of wilder temperature swings associated with those systems, Bourn said. To date, Oklahoma has not been a strong market for geothermal systems. One reason is that natural gas costs in the state have traditionally been low, so consumers have not been motivated to seek alternative power sources. In addition, state utilities in Oklahoma have not promoted the use of geothermal energy, with the exception of OG&E, Bourn said. In contrast, Indiana, Pennsylvania, Illinois and Missouri have been ClimateMaster's best markets for geothermal systems. In Indiana, Bourn said that progress was due in part to the cooperation of most utilities in the state, from the largest regulated provider to small rural electric co-ops. Those companies even working with ClimateMaster to host on-site visits whenever a new geothermal system was installed, and Bourn said hundreds of people attended some of those demonstrations. If installed on a new house, a geothermal system provides a "positive cash flow from the first day," Bose said. But many consumers remain reluctant to take the plunge. "It's something new," Bose said. "It's just like putting solar panels on the roof: People just aren't ready to do that."