Energy efficiency measures installed as part of a demand-side management (DSM) program result in energy savings over the life of the measure. Accurate estimates of lifetime energy savings are important to administrators to ensure that all benefits of the program are attributed for cost-effective analysis and energy planning. Typically, no energy savings are attributed to a utility program from an energy efficiency measure at the end of its Expected Useful Life (EUL). However, there may be circumstances for which a portion of energy savings are maintained after the EUL of a measure. An investigation was undertaken of the mechanisms for savings post-EUL to develop a method to determine the attribution of energy savings after a program’s anticipated EUL, with a focus on the commercial and industrial sectors. A survey was developed to investigate the rate of measures still installed beyond their EUL, O&M practices, and program influence. This report presents the results of the survey, as well as an analysis of and recommendations for targeted measures previously assigned ex-ante EULs and attributing energy savings post-EUL.
Demand-side management, Energy efficiency, Expected useful life, Persistence