Thermal Energy Systems Specialists

This report summarizes work to develop savings estimates for geothermal heat pump retrofits in residential applications in the four major climate regions of Texas. Substantive Rule §25.181 of the Public Utility Commission of Texas requires electrical utilities in that state to achieve, by January 1, 2004, a minimum 10 % reduction in demand growth through energy efficiency programs designed to reduce customers ’ purchased energy consumption and/or demand. The development of such programs requires estimates of deemed savings1 for various energy conservation measures. Building on work performed during the evaluation of a residential geothermal heat pump retrofit project at a large U.S. Army facility in Louisiana, the authors modeled the performance of a complete neighborhood of 200 multifamily residences, comparing the annual energy consumption and peak demand of geothermal or ground-coupled heat pumps (GCHPs) and 10 SEER air source heat pumps in Amarillo, Dallas/Fort Worth, Houston, and Corpus Christi. Three different GCHP efficiency levels were modeled, and the systems were modeled both with and without desuperheaters to supplement domestic hot water tanks. The medium and high efficiency GCHPs were found to provide significant energy and demand savings in all four cities