Wind and solar power will form the bedrock of a future clean energy system. They are cheap, easy to maintain, widely deployable, and long-lasting. They do, however, have one significant and ultimately unavoidable fault: intermittency.
Over the course of hours and days, this intermittency can be somewhat compensated for using demand response, variable-rate electricity pricing, and short duration storage. Lithium-ion batteries, though still fairly expensive, have become an increasingly economical solution to load balancing challenges. However, wind and solar capacity factors also vary over the course of seasons and years.
Meanwhile, seasonal energy demands such as home heating will need to be decarbonized—likely via electrification. Lithium-ion batteries become significantly less viable solutions for load balancing over these longer timescales because of their inherent technological limitations and because of insufficient market compensation for “stand-by” services.
Balancing a decarbonized grid over seasonal and annual timescales will require several changes in policy and investment priorities including revisions to storage markets, increased transmission investment, and development of alternative storage solutions.