Co-benefits: experience and lessons from the US electric sector

Past experience in the US indicates that a focus on reducing individual types of pollutants can result in success for the targeted pollutants, yet allow continued growth in other pollutants, most notably CO₂. The electric industry has demonstrated the capacity to make large investments in controlling emissions, as well as in developing new generation sources. In the absence of multi-pollutant regulations, investments in specific emissions controls may subsequently prove non-useful as new pollutants are regulated. The most effective approach to achieving co-benefits is to anticipate future regulatory constraints and invest in non-polluting technologies and energy efficiency. However, estimating the emissions avoided due to energy efficiency is not straightforward. In the United States, "displaced" emissions are spatially and temporally non-uniform due to the distribution of energy production and energy market dynamics. Emissions data exist to understand this variation and may be used to target programs. Analysis of program results reveals that energy efficiency programs exhibit economies of scale. The case of Southwest Connecticut provides an example of a co-benefits approach to addressing conflicting results of several policies. Efficiency programs have a high potential to reduce both carbon emissions as well as other pollutants. Significant consideration must be given to techniques to account for the emissions benefits of these programs.