Measurement and improvement of the energy efficiency at pumping stations

Abstract

Rational and efficient use of energy is essential for sustainable development. In Spain, as in many other countries, electrical energy is the main source of energy in irrigation; therefore, research with the aim of increasing the efficient use of electrical energy should be arranged. The goal of the research performed was to develop a model for analysing energy efficiency at pumping stations, which permitted the determination of the sequence of pump activation that minimised the energy cost for real demand scenarios. The model was calibrated for the pumping station of Tarazona de La Mancha (Spain) by measuring hydraulic and electrical parameters for each pump. One of the main aspects to consider when carrying out the energy cost analysis at pumping stations is to estimate the discharge distribution throughout the irrigation season. The optimum sequence of activation of pumps was the option that best fitted the discharge distribution in terms of efficiency. This paper illustrates that simple electrical and hydraulic measurements at pumping stations can help to improve their management. In the case study, a cost saving of 16% was obtained by changing the regulation of the pumping station. In only one season, the additional costs of applying this methodology (electrical network analysers, flowmeters, and pressure transducers) would have been recovered with the energy efficiency improvement. Results could vary in other cases depending on the discharge distribution and the working points of the pumps.