Output value of grid-side energy storage projects

First, our results suggest to industry and grid planners that the cost-effective duration for storage is closely tied to the grid's generation mix. Solar-dominant grids tend to need 6-to-8-h storage while wind-dominant grids have a greater need for 10-to-20-h storage.

This research's focus is also motivated by the rapidly decreasing cost of grid-scale batteries; the last decade saw a 70% reduction in lithium-ion battery packs' price. In my model, private returns to storage are maximized by trading on intra-day price fluctuations in the wholesale electricity market.

A grid-scale energy storage firm participates in the wholesale electricity market by buying and selling electricity. Energy storage creates private (profit) and social (consumer surplus, total welfare, carbon emissions) returns. Storage generates revenue by arbitraging inter-temporal electricity price differences.

The total (a), regional (b), hourly (c), and monthly (d) distributions in the mean marginal electricity prices as the amount of mandated long-duration energy storage (in TWh) increases. Increases up to 20 TWh significantly decrease the variability in marginal prices while increases beyond 20 TWh have a lesser effect.

Energy storage creates private (profit) and social (consumer surplus, total welfare, carbon emissions) returns. Storage generates revenue by arbitraging inter-temporal electricity price differences. If storage is small, its production does not affect prices.

This study models a zero-emissions Western North American grid to provide guidelines and understand the value of long-duration storage as a function of different generation mixes, transmission expansion decisions, storage costs, and storage mandates.