New Indicators to Discriminate the Cause of Low Energy Efficiency in Deep-Well Pumps

The extraction of groundwater for irrigation with submerged pumps in deep wells is energy intensive, but is essential for irrigated agriculture in arid and semi-arid regions. To evaluate the performance of these pumping stations, there are several commonly used energy efficiency indicators that show whether the pumping system is working properly or not, but they do not indicate the cause of inadequate performance. Therefore, the goal of this paper is to propose, calibrate and validate a set of new indicators, to identify the possible cause of inefficiencies in the design and operation of deep-well pumps and to serve as a helpful tool in decision-making throughout their life cycle. After their definition, they were applied to 22 pumping wells for calibration, and were validated in a single pumping well in three different stages of its life cycle. The results show that wells with low energy efficiency (41%) have operational problems (33%), design problems (11%) or both (56%). The application of the indicators to a well in three stages of its life cycle allowed preventive maintenance to be performed, generating energy savings of 11% with a payback period of 0.6 years, which proves the usefulness of the indicators with regard to improving energy management and the maintenance of well pumping in the different phases of the life cycle.