Actual energy savings after retrofit: Electrically heated homes in the Pacific Northwest

The Bonneville Power Administration operated an interim Residential Weatherization Program during 1982 and 1983 throughout the Pacific Northwest. The program offered free home energy audits and financial incentives to help pay for installation of recommended retrofit measures in electrically heated homes. Almost 104,000 homes were retrofit during the two years the program operated at a cost to BPA of almost $160 million. This study analyzes actual electricity savings for about 1000 homes that participated in the BPA program in 1982 or 1983. The data for each household include electric utility bills for one year before and one year after retrofit; daily temperature data for weather stations near these households; energy audit reports and postinstallation inspection forms; and information on household demographics, structure characteristics, and heating fuels from surveys conducted in Fall 1983 and June 1984. The major factors related to actual household electricity savings after retrofit are: preretrofit electricity use, audit estimate of electricity saving for measures installed, changes in electricity prices, and changes in primary or supplemental heating fuels (especially shifts to and from wood). Together, these factors explain no more than half the variation across households in actual savings.