A critical comparison of methods for benchmarking energy performance in WWTPs

The energy efficiency of wastewater treatment plants (WWTPs) is a subject of growing interests by water utility and WWTPs operators. As consequence, benchmarking in recent years has become an important tool to assess the performance of these facilities and help identify best practices. This study compares various benchmarking methodology employed for the assessment of the energy efficiency in WWTPs. The literature review revealed three main benchmarking approaches: normalization, statistical techniques and programming techniques. Advantages and disadvantages were identified for each one. It was found additionally that no single Key Performance Indicators (KPIs) used to characterize the energy performance could be used universally. In general, while these methods can be used for comparison, the diagnosis of the energy performance remains an unsolved issue