Carnegie Mellon University
May 18, 2012

Press Release: Carnegie Mellon Engineering Researchers Find Geography Plays Key Role in Emission Benefits of Renewables, Energy Efficiency Measures

Contact: Chriss Swaney / 412-268-5776 /

PITTSBURGH—A new report by Carnegie Mellon University researchers finds significant regional differences in the emission benefits of renewable and energy efficiency measures.

Kyle Siler-Evans, a Ph.D. researcher in the Department of Engineering and Public Policy from Santa Fe, N.M., working with professors Ines Azevedo and M. Granger Morgan, has found that compared to California, displacing 1 kilowatt-hour of electricity in Iowa is expected to avoid roughly 70 percent more carbon dioxide, 12 times more sulfur dioxide and three times more nitrogen oxide emissions. 

The study, recently published in the journal Environmental Science & Technology, found that energy efficiency measures in the Midwest and parts of the mid-Atlantic would primarily displace coal-fired generators, resulting in significant emission reductions.

By contrast, energy efficiency measures in Texas, the Northwest and the West will primarily displace gas-fired generators, yielding much smaller reductions in carbon dioxide, nitrogen oxide and sulfur dioxide.

"The dirtier the grid, the greater the benefit of an energy efficiency measure," said Siler-Evans. "This work has important implications for public policy. If our goal is to reduce emissions, we should focus energy-efficiency investments in places like Wisconsin, Iowa or Pennsylvania. In California, given how clean the electricity mix, we get relatively little emissions savings from additional investments in energy efficiency."