Assessing Improvement in the Energy Efficiency of U.S. Auto Assembly Plants

Abstract

this objective and to provide a measure of a manufacturing plant’s energy efficiency, ENERGY STAR developed a statistical benchmarking approach. This approach, embodied in the ENERGY STAR Energy Performance Indicator (EPI), estimates the energy use of “best in class” plants and the range of performance across the industry. The first EPI was developed for automobile assembly plants using data from the year 2000, and was updated in a second EPI with 2005 as the base year. In addition to providing the industry with a tool to benchmark its plant energy performance, the process of updating the tool has allowed EPA to document improvement in the industry’s overall energy performance for 2000-2005. We find that electricity use per vehicle in the best plants improved by 2%, while the fuel use per vehicle improved a dramatic 12%. These changes resulted in a reduction of 696 million pounds of carbon dioxide (CO2) emissions at the plants used for this study. The range of performance in fuel use has also narrowed over time, implying that other plants have been catching up to the best-in-class plants. This catching up contributes a reduction of another 766 million pounds of CO2, for a total reduction of nearly 1.5 billion pounds of CO2. This paper describes the voluntary ENERGY STAR program policy approach selected to engage and motivate the automobile manufacturing industry to improve its energy performance, and the results of the industry's efforts to advance energy management as measured by the updated EPI.