The relationship between irrigation-induced electrical loads and antecedent weather conditions in Tasmania, Australia

Over the past decade in Australia, there has been a general trend towards the introduction of electrical motors to operate irrigation pumps. While electrical motors provide many advantages over the alternatives, electrical loads can aggregate in some areas to become large peaks, which challenge the existing electrical distribution networks. This is especially true during extreme hot or dry periods, when irrigators collectively demand significant electrical resources at the same time. While there is an inherent link between weather conditions and the amount of electricity used for irrigation, this relationship is poorly understood. Previous studies have either focused on localised data related to concurrent temperature, rainfall and soil moisture, or they have annualised summaries over large areas. In this study, we compare intensive irrigation periods with the drought factor at a case study irrigation scheme in Tasmania, Australia, finding a strong relationship between electrical load and periods when the drought factor is > 6. This relatively simple relationship may be useful for managers of electricity supply and distribution, managers of water resources, and irrigators, as it may be used to minimise the risk of exceeding the capacity of the electricity network, improve water availability and optimise irrigation scheduling.