Addressing the Low-carbon Million-gigawatt-hour Energy Storage Challenge

The energy system of the United States requires several million gigawatt hours of energy storage to meet variable demand for energy driven by (1) weather (heating and cooling), (2) social patterns (daily and weekday/weekend) of work, play and sleep, (3) weather-dependent energy production (wind and solar) and (4) industrial requirements. In a low-carbon world, four storage options can meet this massive requirement at affordable costs: nuclear fuels, heat storage, hydrocarbon liquids made from biomass, and hydrogen. Because of the different energy sector characteristics (electrical supply, transportation, commercial, and industrial), each of these options must be developed. Capital costs associated with electricity storage at this scale using, for example, batteries and hydroelectric technologies are measured in hundreds of trillions of dollars for the United States alone and thus are not viable.