Industrial power and energy metering – a state-of-the-art review

This paper provides a review of the state-of-the-art in electrical energy metering, with a particular focus on energy metering in complex manufacturing facilities. Higher levels of quantification and visibility in energy consumption is necessary due to the rising energy costs and proposed environmental taxes, which are forcing industrial enterprises to improve their energy efficiency. Traditionally, decisions relating to the planning and operation of complex manufacturing facilities have been based solely on conventional metrics such as raw material costs, labour costs and productivity with respect to market demands. Energy consumption has rarely been considered as a driver of manufacturing strategy; however this issue is becoming more prevalent, and is a topic of concern in the board room and a topic of significant research interest in the last five years. By integrating energy consumption criteria into a facilities planning and operating structures, a reduction of energy costs is to be expected. Such criteria and metrics include peak shaving, adapting the production program to external conditions such as energy prices or renewable energy availability, and implementing best practice energy management standards. In order to accurately quantify the effectiveness of projects designed to improve energy efficiency, it is first necessary to assess current performance. Power and energy metering equipment is essential for this assessment and in addition also allows the measurement of a wide variety of additional electrical statistics related to power quality such as voltage sags and surges to more complex power quality disturbances, for example harmonic distortion. The technologies available and the associated measurement and inference is presented in this paper.