Energy efficiency in irrigation distribution networks I: Theory

The energy consumption of the pressure irrigation distribution systems is strongly influenced by both the proper functioning of the pumping stations and by the spatial distribution and layout of the networks. In this paper a method of calculating the global energy efficiency (GEE) of irrigation distribution systems is proposed. This includes the pumping energy efficiency, which depends on the efficiency of the pumping stations, and the supply energy efficiency, which depends on the spatial distribution and layout of the system. Two procedures are presented to obtain the GEE, one as a water head balance and power approach; the other as an energy approach. The method has been applied to a hypothetical but representative example of an irrigation distribution system. The results show that the procedure is useful for identifying the causes of efficiency loss and that it can be used as a tool for rehabilitation of an existing system, or the evaluating energy efficiency of a new design.