Energy Efficiency, Emissions, and Policy: Strengthening the Links

Panel: Energy and Environmental Policy: Planning for Greater Impacts

Authors:
Eric Rambo, PA Consulting Group
David Sumi, PA Consulting Group
Bryan Ward, PA Consulting Group
Oscar Bloch, Wisconsin Public Service Commission

Abstract

The Wisconsin Focus on Energy evaluation team uses emission factors to calculate environmental impacts from Focus on Energy net energy savings. As part of the inputs to the Focus benefit-cost analysis, the evaluation team provides updated emissions factors based on the Environmental Protection Agency's Office of Air and Radiation "Acid Rain Hourly Emissions Data." In the FY07 emissions research we noted significant changes in the factor estimates for NOx, SOx, and CO2 relative to an earlier analysis based on 2000 EPA data. To better understand these changes, the Focus team re-estimated emissions factors on five years of EPA data,spanning 2002 to 2006. These are reported here. We also report the effect on emission rates of three different definitions of plants that are on the margin. This concept identifies the source ofemissions that would be avoided or displaced by energy efficiency programs. We find thatemission rate estimates are quite sensitive to the definition. We propose a definition of marginal plant based on the length of time a unit remains on once it is called on, which we term the "use rate." We also report preliminary findings on trends in emission rates over five years.