For many power companies generating electricity, the amount of electricity that can be generated is a fixed amount over short periods of time, while the demand for electricity fluctuates throughout the day. Developing technology to store electrical energy so it can be available to meet demand whenever needed is a major breakthrough. Batteries, hydrogen and pumped hydro (leveraging the potential energy of water that has been pumped to higher elevation) are common forms of electric energy storage.

The generation of electricity with nonrenewable energy has to be started and stopped as demand fluctuates. It takes time to ramp up these generation facilities which limits their ability to respond to spikes in demand in real time.

With renewable energy resources, energy storage is equally useful. These energy sources are intermittent in nature, producing energy when the sun is shining and the wind is blowing. By storing the energy produced and delivering it on demand, renewables can continue to power our grid even when the sun has set and the air is still.

Electricity storage devices can manage the amount of power required to supply customers during peak load when need is greatest. These devices can also benefit microgrids by balancing generation and load.