The difference between 4 hours of energy storage and 2 hours of energy storage

What is storage duration?

Storage duration is the amount of time storage can discharge at its power capacity before depleting its energy capacity. For instance, a battery with 1 MW of power capacity and 4 MWh of usable energy capacity will have a storage duration of four hours.

Should energy storage be more than 4 hours of capacity?

However, there is growing interest in the deployment of energy storage with greater than 4 hours of capacity, which has been identified as potentially playing an important role in helping integrate larger amounts of renewable energy and achieving heavily decarbonized grids.1,2,3

How long can a battery energy storage system deliver?

How long the battery energy storage systems (BESS) can deliver, however, often depends on how it’s being used. A new released by the U.S. Energy Information Administration indicates that approximately 60 percent of installed and operational BESS capacity is being exerted on grid services.

What is the difference between rated power capacity and storage duration?

Rated power capacity is the total possible instantaneous discharge capability of a battery energy storage system (BESS), or the maximum rate of discharge it can achieve starting from a fully charged state. Storage duration, on the other hand, is the amount of time the BESS can discharge at its power capacity before depleting its energy capacity.

Can 4 hour storage meet peak demand?

The ability of 4-hour storage to meet peak demand during the summer is further enhanced with greater deployments of solar energy. However, the addition of solar, plus changing weather and electrification of building heating, may lead to a shift to net winter demand peaks, which are often longer than can be effectively served by 4-hour storage.

Will a fifth hour of battery storage cost more than 4 hours?

value for a fifth hour of storage (using historical market data) is less than most estimates for the annualized cost of adding Li-ion battery capacity, at least at current costs.25 As a result, moving beyond 4-hour Li-ion will likely require a change in both the value proposition and storage costs, discussed in the following sections.