Optimum pumping station management for irrigation networks sectoring. Case of Bembezar MI (Spain)

Abstract

Changing from old open channel distribution systems to pressurized irrigation networks to improve water use efficiency has involved an increase in energy consumption. As total energy costs have significantly increased in recent years, modernization is sometimes an additional problem for farmers because it has led to increased water-related costs. Several authors have highlighted that irrigation system sectoring, where hydrants are grouped in sectors with similar energy requirements, is one of the most efficient energy saving measures. However, with sectoring the pumping station may have to work under flow and pressure conditions that are very different from its optimum operational point, which would make it impractical from an operational standpoint. In this study, a new model (WEBSOMPE), which optimizes the sectoring operation and pressure head, has been developed and applied in a typical irrigation district in Southern Spain. The benefits of the installation of up to three variable speed drives have been modeled and analyzed. The joint use of sectoring and VSDs (Variable Speed Drives) would lead to energy savings of up to 26% and guarantee the service pressure at the hydrant level. One major benefit over the alternative of replacing pumps is that the installation of VSDs would not represent major investments in infrastructure.