A non-energy impact (NEI) is an additional benefit (positive or negative) for participants in energy efficiency beyond the energy savings gained from installing energy efficient measures. NEIs include benefits such as reduced costs for operation and maintenance associated with efficient equipment or practices, or reduced environmental and safety costs. There are NEIs attributable to both participants and to society at large. NEIs are being considered, in addition to energy and cost savings, when making decisions about cost-effective energy efficiency investments in order to account for impacts such as avoided pollution, economic development, improved system performance, and deferring system upgrades. NEIs are also referred to as non-energy benefits (NEBs), but for the purpose of this report and to remain consistent, NEI will be the terminology used.