Measurement and Verification of Energy Efficiency Savings in Industrial Facilities: The flaw of using energy intensities to de- termine savings

摘要

Energy intensities have widely been used as a key performance indicator to track and report on the overall energy performance of an industrial plant or facility. The same energy intensity figures have then also been used to determine the energy savings over time. Energy managers have used reduction in energy intensities over time to determine energy savings. This is a method that has been widely applied across all types of industries and has worked very well over the last number of years, with the world economy booming and growing each year.rnHowever, with the slow-down in the economy, industrial plants suddenly started to experience drops in overall efficiency. All the savings they accrued over these years were "lost," although no changes were made to the plants and facilities. The energy intensities of the plants started to increase.rnThis article focuses on and describes the flaw of using energy intensities to determine energy efficiency savings. It describes how the physical characteristics of industrial plants are influenced by controllable and uncontrollable energy drivers and how these drivers should be incorporated into the measurement and verification process. The methodology is also applied to a case study.