What is an energy storage system?

An energy storage system (ESS) for electricity generation uses electricity (or some other energy source, such as solar-thermal energy) to charge an energy storage system or device, which is discharged to supply (generate) electricity when needed at desired levels and quality. ESSs provide a variety of services to support electric power grids.

What happens if you don't have energy storage?

Without energy storage (i.e., how the electric grid has been for the past century), electricity must be produced and consumed exactly at the same time. When you turn on a hairdryer in your home, somewhere, an electricity generation plant is turning up just a tiny bit to keep the grid in balance.

Why do we need energy storage systems?

When you turn on a hairdryer in your home, somewhere, an electricity generation plant is turning up just a tiny bit to keep the grid in balance. Energy storage systems allow electricity to be stored—and then discharged—at the most strategic times.

How does energy storage work?

Energy storage can provide support in the following load changes of electricity demand. In other words, storage can act as an energy source or sink in response to both load and generating capacity changes. Most types of storage can also respond much more quickly than typical rotary generators when more or less output is needed for load following.

When is energy stored?

In other words, the energy is stored when there is excess in renewable energy production and it is released to the grid during periods of high demand (Fig. 20). The storage technology must be scalable and able to provide energy for some minutes to some hours.

Should solar energy be combined with storage technologies?

Coupling solar energy and storage technologies is one such case. The reason: Solar energy is not always produced at the time energy is needed most. Peak power usage often occurs on summer afternoons and evenings, when solar energy generation is falling.