Emitting less without curbing usage? Exploring greenhouse gas mitigation strategies in the water industry through load shifting

Growing interest in greenhouse gas mitigation strategies to address global climate change has resulted in the rapid expansion of renewable electricity sources. However, increasing power generation from variable renewable electricity sources, such as solar photovoltaics and wind turbines, has made balancing electricity supply and demand across the power grid more challenging. In some regions, high penetrations of variable renewables have also created electricity supply systems where electricity is significantly cleaner in hours when renewable energy is abundant, in comparison with peak demand hours when fossil fuel-based generation is often dominant. In the absence of cost-effective, utility-scale batteries, demand response strategies that leverage flexibility in electricity consumption have gained interest as readily available resources to address the temporal mismatch between renewable energy availability and high energy demand periods. The water industry (i.e., water supply and wastewater systems) includes industrial customers that are particularly attractive in terms of demand response potential as they can offer flexibility through large interruptible pumping loads, large water storage capacities, and energy generation potential. This study explores flexibility strategies in the water sector motivated primarily by the goal of reducing emissions, rather than cost. We present an illustrative case study demonstrating that strategically shifting 5% of the total daily average electricity load of a cluster of 97 water-supply electricity consumers in California across the year can reduce annual carbon dioxide emissions by 2–5%. In the end, important future research directions are discussed to support the implementation of flexibility measures in the water industry.