In pressurized irrigation networks that use underground water resources, submersible pumps are one of the highest energy consumers. The objective of this paper was to develop a decision support system, implemented in MATLAB®, to reduce the energy consumption of the water abstraction process, from an aquifer to a reservoir in existing wells, by installing a frequency speed drive. An economic module with the aim to assess the economic profitability of the investment cost of the variable speed drive was also developed. This tool was used in three wells that were located in the Eastern Mancha Aquifer. Several scenarios and irrigation seasons were analyzed while considering the interannual and annual variation in ground water depth. In the three analyzed irrigation societies (named A, B, and C), energy savings were achieved using a variable speed frequency when compared with fixed speed. Considering the analyzed cases, when the dynamic water table level is higher, energy savings ranged from 4.4% and 24.4%, using a variable speed ratio of 0.9 and 0.82. The energy savings based on the variable speed frequency increased when the dynamic water table level was lower, with the average energy savings close to 23%, 22% and 6.8% for irrigation societies A, B, and C, respectively. The results also show that the investment costs of the variable speed drive in two of the three irrigation societies studied were highly profitable, with a payback that ranged from 4.5 to 10 years.

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ResumenSe ha desarrollado la herramienta DRODN (Design of Reservoir On Demand Network) (implementada en MATLAB) con un enfoque holístico para determinar en una red colectiva de riego a la demanda el mínimo coste total (C T ) (incluyendo los costes de inversión (C i ), operación (C e ) y mantenimiento (C m )). El procedimiento determina el volumen óptimo de la balsa de almacenamiento y regulación intermedia teniendo en cuenta las tarifas eléctricas y la disponibilidad de agua en el sondeo, la evolución de la demanda de agua de la red a lo largo de la campaña de riegos utilizando el método de curvas aleatorias de demanda diaria (Random daily demand curve) (RDDC). La herramienta se ha aplicado a una red de riego de 171 ha, que riega por goteo viña y olivar, localizada en la provincia de Cuenca (España). Los resultados indican que el volumen óptimo de almacenamiento y regulación está alrededor de los 5 000 m 3 , y el C T para ND = 100 m es 325 € ha -1 año -1 . El C e es el principal componente del C T , representando más del 63% en los casos estudiados. La forma de operación y manejo de la red de riego condiciona las dimensiones de la balsa y los costes anuales de suministro.