— Energy Storage —

Batteries, like those in flashlights or cell phones, can also be used to store energy on a large scale.

The electricity grid is a complex system in which power supply and demand must be equal at any given moment. Constant adjustments to the supply are needed for predictable changes in demand, such as the daily patterns of human activity, as well as unexpected changes from equipment overloads and storms. Energy storage plays an important role in this...