Energy, Vol.53, 237-243, 2013
Operational energy-efficiency improvement of municipal water pumping in California
This paper implements a normalization/regression-based approach to estimate the kWh energy and kW savings from an experimental OEEP (operational energy-efficiency program) for municipal water pumping in California. The voluminous 1-min data collected in the course of the OEEP presents a unique opportunity to analyze how VSD (variable-speed drive) technology aided by a PLC (programmable-logic-controller) may improve municipal water pumping's operational energy efficiency. Our proposed approach enables a comparison of pump operations with and without the OEEP, yielding accurate estimates for kWh energy and kW capacity savings that are useful in evaluation, monitoring, and verification of the program. Our findings lead us to conclude that (a) variability of efficacy by analyzed pump sites suggests targeted implementation of the OEEP; and (b) for a correctly-sized pump operating near its optimal kW-output value, adding a VSD and PLC can actually harm the pumping system's overall energy-efficiency. (C) 2013 Elsevier Ltd. All rights reserved.