By Vernon Robison
Moapa Valley Progress
An experimental renewal energy resource seems to be paying off for the Overton Power District (OPD). According to a report made to the OPD Board on Wednesday, September 15, a ground source heat pump installed in the OPD Mesquite building complex should see an approximate 10 year pay back period. This means that the savings in energy cost brought about by the system should equal the cost of installing the system within a decade.
A ground source heat pump is a central heating or cooling system that uses the geothermal forces in the earth as a heat source (in winter) or as a heat sink (in summer). The design takes advantage of the moderate temperatures deep in the ground to boost efficiency and reduce the operational costs of heating and cooling systems
“Of everything that we have looked at involving renewable energy, this has come the closest to paying for itself,” said OPD General Manager Delmar Leatham.
In recent years the OPD has conducted similar studies and experiments in the areas of solar and wind power generation.
The report presented to the OPD Board compared the district’s Mesquite buildings, which are equipped with the renewable energy system, with the Overton building which is not.
It was estimated that the Overton building carries and annual power cost of around 14 cents per square foot. The Mesquite administrative building on Turtleback Road, on the other hand, operates at around 10 cents per square foot. And the nearby OPD Engineering building costs about 7 cents per square foot.
Given these figures, the report projected an annual total saving of $7,617.
The construction costs involved with drilling and putting the wellfield in place for the ground source heat pump facility was about $74,000, the report stated.
“So that gives us about a 10 year payback on the system,” Leatham concluded. “And that doesn’t account for any future rate increases that may come along.”
Leatham added that the scenario was made successful because the district was not required to borrow money to build the facility. “This may not work as well for the residential customer who has to borrow money to install the system,” he said. “If you have to service a debt, it could double the payback time and it wouldn’t make as much sense.”
