In order to provide users an idea of how much they could potentially save on their energy bills, we have estimated technical savings potentials for typical houses in 19 U.S. regions. These estimates of savings potential are applied to the average existing energy bills by climate region, as described in the previous section. Users see this information immediately following entry of their zip code.
To estimate the potential savings, we select a single house from the 2005 RECS sample to represent each census division. These houses are selected such that their utility bills are within 10% of the median value in each census division, and they have the heating and cooling equipment most common in that census division. These selected houses are single-family detached, with floor area ranging from 1100 to 2900 square feet. 2005 RECS utility bill data are inflated to 1995 dollars using the Consumer Price Indices for electricity, piped gas, and fuel oil. The characteristics of the selected houses are shown in Tables 26 and 27.
We then estimate the utility bills for these houses, assuming that “best available” technology were applied to the building shell and the equipment contained in that house (according to the RECS survey). Best available technology is generally defined as the most efficient products on the market. The savings estimates are based on several sources, including an LBL supply curves analysis (Koomey et al. 1991) and unpublished updates to that analysis; the U.S. DOE Water Heater standards analysis (U.S. DOE 2000c); a U.S. EPA analysis of space conditioning efficiency improvements (L’Ecuyer et al. 1993); the Honeywell Thermostat Energy Savings Estimator program (Honeywell 1994); Mark Modera (1998); and model directories from the Air conditioning and Refrigeration Institute (ARI 1995), Gas Appliance Manufacturers Association (GAMA 1996), and the California Energy Commission (CEC 1998). The resulting savings factors are shown in Table 27. For lighting, we assume 50% savings are achievable with a combination of compact fluorescent lamps and outdoor lighting controls.