Energy from fossil or nuclear power plants and renewable sources is stored for use by customers. Grid energy storage, also known as large-scale energy storage, is a set of technologies connected to the electrical power grid that store energy for later use. 1 Batteries are one of the most common forms of electrical energy storage. The first battery, Volta's cell, was developed in 1800. It helps maintain the balance between energy supply and demand, which can vary hourly, seasonally, and by location. Energy can be stored in various forms, including: When people talk about energy storage, they typically mean storing. As America moves closer to a clean energy future, energy from intermittent sources like wind and solar must be stored for use when the wind isn't blowing and the sun isn't shining.