Energy cost optimization in pressurized irrigation networks

The increasing demand and price for energy are affecting all economic sectors, including irrigated agriculture. This sector has undergone substantial transformations to improve water use efficiency by adapting its open-channel distribution systems to pressurized networks, which entail greater energy consumption and hence higher energy costs. Farmers are therefore demanding measures to reduce energy costs and ensure the profitability of their farms. In this paper, previous energy optimization models focusing on network sectoring (WEBSOM) and critical points control (WECPM) are improved by incorporating an electricity tariff module that considers different energy prices according to the hour of the day and the day of the year. The model permits determining the minimum energy cost affected by different operation conditions of the network. The methodology has been analyzed in an irrigation network located in southern Spain in which different operation scenarios were evaluated: operation with and without sectors and with and without critical points control. The results show that adopting measures to improve the operation of critical points in months of peak energy demand and operation by sectors in the others leads to a 13 % cost savings compared to the baseline scenario where only pressure heads at the pumping stations are optimized. The proposed model is a decision-making support system that integrates alternative irrigation network operation scenarios with the structure of the electricity tariff.