Energy from wind and solar sources is available when nature permits, but the demand for energy is based on the cyclical needs of people and their activities. To make renewable energy work, and to manage the normal daily mismatches between supply and demand, we need to shift energy in time from when it is available to when it is needed. That calls for grid-scale storage.

To explain large-scale energy storage strategies, we talk with Nate Blair, group manager of distributed systems and storage analysis at the USDOE National Renewable Energy Laboratory in Golden, Colorado.