Policy recommendations for using cool thermal energy storage to increase grid penetration of renewable power sources (1607-RP)

The majority of U.S. states have adopted policies intended to increase renewable energy generation. Because of the intermittent nature of wind and solar resources, in particular, several states have also adopted energy storage policies. Energy storage serves to bridge mismatches between intermittent electricity production and demands from end-use electricity consumers. Because building air-conditioning loads commonly drive peak electric grid demands, storage in the form of thermal energy is an attractive alternative to electric storage technologies. Cool thermal energy storage systems have been used successfully for decades by building owners seeking to shift air-conditioning system electric consumption to off-peak time periods when electricity rates are low. In the current article, the authors present a strategy for controlling cool thermal energy storage systems to enable an increased penetration of intermittent wind and solar generation. It was found that cool thermal energy storage systems operated using this strategy have not only reduced life-cycle costs compared to air-conditioning systems without cool thermal energy storage, but they more effectively utilize the renewable resource. Because cool thermal energy storage is a mature technology and the results show that cool thermal energy storage is more cost-effective than electric energy storage technologies currently in widespread use, policies that aim to increase renewable energy generation should also support increased deployment of cool thermal energy storage as an enabling technology.