Evidence for Action on Energy Efficiency

The E2e Project is a joint initiative of the University of California at Berkeley, the University of Chicago, and the Massachusetts Institute of Technology.

World class researchers tackling the energy efficiency gap

E2e has built a community of top tier researchers pursuing the frontier of energy efficiency research.

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A growing body of evidence

With several recently-launched and on-going projects, E2e researchers are analyzing all aspects of the energy efficiency gap.

Featured Research

Decomposing the Wedge Between Projected and Realized Returns in Energy Efficiency Programs Peter Christensen, Paul Francisco, Erica Myers, and Mateus Souza

Evaluations of energy efficiency programs reveal that realized savings consistently fall short of projections. This paper decomposes this 'performance wedge' using data from the Illinois Home Weatherization Assistance Program (IHWAP) and a machine learning-based event study research design. The authors find that bias in engineering models can account for up to 41% of the wedge, primarily from overestimated savings in wall insulation. Heterogeneity in workmanship can also account for a large fraction (43%) of the wedge, while the rebound effect can explain only 6%. They find substantial heterogeneity in energy-related benefits from IHWAP projects, suggesting opportunities for better targeting of investments.