Two years ago, in researching energy options for an affordable housing development, I came across a remarkable discovery-a cost-effective, proven renewable technology for heating and air conditioning. Upon further research, I learned that in 1993 the Environmental Protection Agency had pronounced geothermal heat pumps, "the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available."

The systems, also called "geoexchange" technology, were proven to be 48 percent more efficient than gas-fired heating systems and 75 percent more efficient than oil-fired systems. The key difference between geothermal and other renewable technologies such as solar, is its cost-effectiveness.

I did a "white paper" for the Governor, detailing the amazing success of over half a million geothermal heat pump installations across the country. This resulted in the governor's news conference on Earth Day 2001 at the Westchester Country Club in Harrison, and his continuing promotion of this technology with millions of dollars in incentives offered by New York State.

Completed last summer by RJ Dooley and Associates, the 280,000 square foot country club is the largest retrofit of geothermal heat pumps in the state. The firm drilled 180 holes under the golf course--each 300 feet deep--to provide heating and cooling at the club and save about $120,000 a year in energy costs.

The technology takes advantage of the fact that the temperature of the Earth below six feet is constant at about 55 degrees in this part of the country.

A system of water-filled pipes in a closed loop system use the Earth as a heat source in the winter and a heat sink in the summer. In winter, the water picks up heat from the ground, where it is extracted in the heat pump and transferred by a conventional forced hot air system to the building. In summer, at the flick of a switch, the same system operates in reverse. The same pump acts as an air-conditioner as it sends cool air into the building, while transferring heat into the ground.

Because of the system's design and the fact that the same water circulates in a closed loop system, there are no negative environmental effects. Since the technology eliminates furnaces, there are no fossil fuels burned on site, eliminating tons of pollution. Because of the system's efficiency in summer, states are using geoexchange to eliminate or reduce the need for new power plants.
The country club retrofit was a massive undertaking-a 280,000 s.f. former hotel built in 1922 that required new piping throughout to phase in 500 heat pumps, while allowing residents to remain in their apartments.

As of September, the hotel had eliminated its antiquated boilers and air-conditioners, along with 345 tons of Carbon Dioxide each year.

With the system working in much of the club for nearly one year, it has exceeded expectations by reducing energy costs by more than 40%, with better comfort than even the most advanced conventional gas-fired systems.

Electricity runs the system, but because electricity is used only to move the heat, instead of generate it, about four kilowatts of energy are generated for each kilowatt used.

Based on a study by Oak Ridge National Laboratory, every ton of geoexchange capacity results in a .65 kw reduction in peak electricity demand. With 600 tons of capacity, The Westchester Country Club conversion alone is reducing peak electricity demand for Con Edison by 325 kw.

The system cost the country club about $135,000 more than a conventional system, after a rebate from the New York State Energy Research and Development Authority (NYSERDA). Given the annual energy savings, the return on investment for the additional cost of the system approached 90%. NYSERDA continues to provide generous rebates for geothermal heat pumps in commercial buildings.

The federal government has recently been specifying geoexchange for many of its new projects, since President Bush installed a system in his ranch house in Crawford, Texas in the fall of 2000.

While NYSERDA has been promoting geoexchange for commercial buildings-both large and small--with generous rebates, most of the 650,000 systems nationwide are in homes. Since the loops may be installed vertically, land is usually not an issue.

While geothermal heat pumps are more expensive to install than conventional gas or oil systems, the savings of 40% to 50% achieve a return on the additional investment of about 20%. They are especially cost-effective in new construction.

Several million square feet of office buildings, schools, and apartment buildings are under construction or have already been completed with geoexchange in New York State in this booming field. Aided by a grant from NYSERDA, a new course at Westchester Community College is training engineers to design and install geoexchange.

For more information on geothermal heat pumps or conventional energy-efficient technologies for business, you may contact Roberts Geo Systems at 914-747-6111.

Alexander Roberts is the president of Roberts Geo Systems, based in Pleasantville and is NYS Certified in Energy Management Practices

[Back]