https://us7.campaign-archive.com/?e=a9fdc67db9&u=9d011a88d8fe324cae8c084c5&id=93183ec05c
What I call the “energy storage conundrum” is the obvious but largely unrecognized problem that electricity generated by intermittent renewables like wind and sun can’t keep an electrical grid operating without some method of storing energy to meet customer demand in times of low production. These times of low production from wind and sun occur regularly — for example, calm nights — and can persist for as long as a week or more in the case of heavily overcast and calm periods in the winter.
If the plan is to power the entire United States by wind and solar facilities, and if we assume that wind and solar facilities will be built sufficient to generate energy equal to usage over the course of a year, we then need to do a calculation of how much storage would be required to balance the times of excess production against those of insufficient production in order to get through the year without blackouts. The challenge of getting through an entire year could require far more storage than merely getting through a week-long wind/sun drought, because both wind and sun are seasonal, producing much more in some seasons than others.
Previous posts on this blog have cited to several competent calculations of the amount of storage needed for different jurisdictions to get through a full year with only wind and sun to generate the electricity. For the case of the entire United States, this post from January 2022 describes work of Ken Gregory, who calculates a storage requirement, based on the current level of electricity consumption, of approximately 250,000 GWH to get through a year. If you then assume as part of the decarbonization project the electrification of all currently non-electrified sectors of the economy (transportation, home heat, industry, agriculture, etc.), the storage requirement would approximately triple, to 750,000 GWH.