Reducing electricity demand peaks on large-scale dairy farms

Abstract

As countries seek to meet climate change mitigation obligations and integrate high levels of variable renewable generation into electricity systems, opportunities for flexible demand are increasingly being sought to provide a cost-effective approach to balancing electricity grids. In New Zealand, the dairy farming sector has the capacity to shift demand outside of peak periods and balance grid demand. We assess the potential for a group of six large-scale New Zealand dairy farms to provide electricity demand flexibility by analysing their electricity demand patterns based on one year of 30 min resolution electricity data. Daily profiles of electricity demand are analysed to demonstrate that irrigation and milking related electricity consumption contribute to peaks. Under a proposed time-of use (TOU) pricing model, 20% of electricity costs in the dairy shed result from the morning peak period. Flattening demand would reduce electricity costs for milking by 3.3% as more of the demand would be overnight and ‘off-peak’. TOU changes to irrigation were found to make responding to peaks more difficult where at least 600 kW had previously been available for load shedding during the irrigation season. If farmers were able to alter their practices or utilise energy storage technologies in response to time-of-use pricing they could reduce energy costs and reduce their impact on peaks in demand on the electricity network.