Verification of electrical energy savings for lighting retrofits using short- and long-term monitoring

This paper presents the verification of the annual electrical energy savings associated with lighting retrofits using short- and long-term monitoring. The effort was part of a US utility-sponsored energy efficiency program to reduce energy consumption in commercial and industrial facilities. Although this paper describes the verification procedures in three facilities, the recommended methods have broad application. In this study, we first conducted lighting energy audits to identify lighting efficiency measures at three facilities, namely an office building, an industrial manufacturing plant, and a city hospital. Then, we estimated the lighting energy savings for the facilities and sought to present the results in a meaningful form. Actual energy savings were measured using short- and long-term monitoring. In all cases, the energy savings measured were within 30% of the projected energy savings.