Plumas-Sierra Electric Cooperative's geo-thermal heat pump program has taken off.
As a result of an aggressive marketing program, 5 percent of Plumas Sierra's members now have ground-source heat pump systems. That represents both new construction and retrofits, according to Member Services Director Nell Thomas.

Wide variety of customers
Customers using GeoExchange systems come from all customer categories, Thomas said. They include modular and mobile homes as well as custom-built upscale homes and businesses.

"The systems are being sold at all economic levels and price ranges," Thomas concluded.

In fact, Plumas-Sierra is even selling its own employees on the technology. Thomas had her home retrofitted with a system last year, and Sharon Swilling, member services assistant, also converted to a ground-source heat pump.

"We had a Field Day for our employees when they installed the system at my home," Thomas said. "The contractor began work on the loops at 8 a.m.., and the system was up and running by 4 p.m."

A Field Day for the public is planned for this spring, when hydronic loops will be installed in the floor of a local firehouse. The loops will carry radiant heat to keep the fire trucks from freezing. "The firehouse is getting financing from the Ground Source Heat Pump Consortium for the project," Thomas added.

Other commercial customers include a local animal shelter, a water treatment plant, and a pool and ice rink. Although the pool and ice rink aren't Plumas-Sierra customers, the cooperative was instrumental in convincing the developers that GeoExchange was the way to go.

Thomas said that subdivisions have also promoted GeoExchange technology, including Gold Mountain Subdivision. Designed by Taliesin Architects, the firm started by Frank Lloyd Wright, the subdivision's homeowners have proven receptive to GeoExchange technology.

"We sent promotional packets about GeoExchange to everyone who bought a lot at Gold Mountain," Thomas said. "Gold Mountain added a letter that endorsed the heating system."

Cost-effective
Given the significantly lower operating costs for GeoExchange, the systems aren't a hard sell. Compared to a 90-percent efficient natural gas system, the GeoExchange costs less than half as much to operate. Initial costs are slightly higher, but Plumas-Sierra offers a geo-thermal loop lease program to make the system more affordable.

Under the program, GeoExchange customers pay a monthly lease fee for the system's loops. The fee is based on the tonnage of the heat exchanger. Costs vary based on whether horizontal or vertical loops are installed.

This leads to reduced drilling costs paid by the customer for system installation. "Plumas-Sierra arranges for the contractors to do a lot of bulk drilling," Thomas said. "The rig comes in and does five or six systems at a time. I already have the permits pulled, and the rig can just go from job to job. That keeps the costs lower because there's no down time."

Thomas cited one resident of Gold Mountain who had a gas heating system installed. Before he even moved into his home, he talked to a neighbor who had a ground-source heat pump. He was so impressed that he had his gas system removed and put in a ground-source heat pump instead.

Other advantages
Operating cost isn't the only attractive feature of ground-source heat pumps. Thomas said the increased level of comfort sells a lot of systems. "There are no cold spots," she explained. "The home is heated evenly."

The systems also offer an environmentally friendly form of energy production. They use less traditional fuel, deriving most of their energy from the earth.

GeoExchange transfers heat trapped in the ground to the air in the homes. At a depth of about 4 feet, the earth's temperature is a constant 52 degrees Fahrenheit. A heat exchanger captures this heat and carries it to the home.

In summer, the same system reverses the process. The heat exchanger carries hot air from the home and discharges it into the ground.

Heat pumps perform well at subdivision
A focus on the environment, low energy costs, safety, and quiet operation led developers of the Whitehawk Ranch Subdivision outside of Clio, Calif., to install ground-source heat pumps at more than 115 residences.

Plumas-Sierra Electric Cooperative serves the homeowners with electricity and helped steer the developers to the GeoExchange technology. So, five years later, how are the systems performing?

Efficiently, according to a case study developed by WaterFurnace International, Inc., the company that supplied the GeoExchange systems. In fact, the case study says, "the overall seasonal performance of these systems is four to five times the efficiency of conventional furnaces."

That efficiency translates to cost savings for owners. The table to the left identifies the cost of all metered energy for a one-year period.