Rosebud Electric begins the third year of energy savings with the electric water source heat pumps that use the municipal water system's thermal capabilities.

The Rosebud Electric headquarters building is using a new innovative way to heat and cool. Heat is transferred, to and from the city water system, with the use of heat pumps to produce fantastically low operation costs.

A separate electric meter records electricity used by the heat pumps for heating and cooling. The past year a total of 18,410 kilowatt hours of electricity were used.... 14,030 for heating, 4,380 for cooling. In dollars and cents that translates to $491.00 for heating and $188.00 to cool.

To put this all into perspective, one can compare the Gregory, South Dakota office, of 6,200 square feet, equal to five 1,240 square foot homes. That would mean each home could heat for $98.20 a year or a combined heating and cooling cost of just $135 for a year! If you know your own heating and cooling costs, a combined cost of $135 a year is fantastically low.

Another way of comparing operation costs is on the square foot basis. The cost per square foot to heat the Rosebud Electric office is 7.8 cents. An energy efficient home with a high efficiency heating system will cost about 28 cents per square foot to operate, or about 3.5 times more than the REC office.

The REC office utilizes four water source heat pumps totaling 12.5 tons of cooling capacity. The system removes, or adds, a few degrees of heat from the municipal water system. By the time water flows a short distance in the mains, it has returned to the main's normal water temperature.

A city's water main system possesses a tremendous ability to transfer heat. Because Mother Nature keeps a relatively constant ground temperature, the water main temperature is relatively constant. The buried pipe network constantly adjusts the water temperature to that of the ground. The network renders nearly an unlimited amount of heat or cooling capacity.

The Rosebud Electric system transfers heat to or from the building to the water systems by means of a heat exchanger. A heat exchange is simply two pipes running side by side. The pipes exchange heat between each other, never does the water from either pipe mix.

The heat pump system offers a heating efficiency of better than 350 percent. For every kilowatt hour of electricity used to run the heat pump compressor, 3.6 kilowatt hours of heat is produced. Because of this efficiency, a kilowatt hour of electricity, which sells for 3.5 cents, now only costs essentially 1 cent. We have now inflation proofed the heating and cooling cost of the building. For example: If in ten years the one cent rate doubled, it would be just two cents as compared to doubling 3.5 which would be 7 cents.

The ground source heat pumps are the heating and cooling systems of the future. They offer both heating and cooling with the greatest efficiencies available and the lowest possible cost of any modern system.