Climate change and future power systems: The importance of energy storage in reduced-hydropower systems in the American Southwest

Abstract

Power systems are responding to climate change both through efforts to reduce greenhouse-gas emissions and through adaptive responses to the effects of climate change, such as changes in hydroelectric generation. These changes, experienced together, may cause new patterns in plant operations or pollutant emissions. Various scenarios representing future climate change mitigation and adaptation in the power sector were explored using the PLEXOS production-cost model, with a focus on plant utilization and behaviour, total system-operating costs and total CO2 emissions. Further, the effect of introducing widespread utility-scale energy storage into these scenarios was quantified in terms of these same parameters. Large increases in variable renewable penetration combined with extreme reduction of hydroelectric generation in the American Southwest (based on climate modelling in the Colorado River basin and actual drought experience in California) caused significant increases in thermal plant start-up/shutdown cycling. The introduction of storage significantly reduced this cycling, without a material increase in CO2 emissions. Storage introduced on even a modest scale can provide considerable flexibility under a range of future power-system circumstances that might be experienced due to climate change.