Measuring the Energy Efficiency of Water Utilities

Energy Benchmarking metrics are applied to water utilities after the 2007 publication of a benchmarking method for water and wastewater utilities based on the EPA's energy star rating system for buildings. This paper explores the application of such benchmarking methods to drinking water utilities in their production stage, and an additional indicator called thermodynamic score is proposed to provide complementary information on the utility's energy efficiency. The thermodynamic score is obtained from a mechanistic approach, in contrast with the applied benchmarking method which comes from an empirical approach. Both metrics were applied to a set of randomly selected utilities in Virginia. Some of the benchmarking scores were found to be skewed. The thermodynamic score proved to be an effective tool for measuring energy efficiency in most cases. The energy analysis of water utilities can be used as an asset management tool by water utilities to proactively manage their infrastructure systems.