Energy storage has become a critical component for both centralized and distributed power grids as greater percentages of intermittent and renewable power generation such as solar and wind are added to the grid. Since the discovery of electricity, energy storage has been used to reduce the cost of power. Mainly because of cost, only recently have electrochemical batteries gained widespread usage for energy storage. Systems, such as the ones listed below, have existed for many years and are used regularly in both grid and backup power systems.
Pumped Hydro: Currently one of the most prevalent and cost-effective energy storage systems deployed for well over one hundred years.
Thermal: Storage of heat or cold for later use. Heat is often stored in molten salts or cold stored as ice to be used later in the form of thermal or electrical energy.
Flywheels: Energy is stored as kinetic energy in the form of a rotating mass. This type of energy can be rapidly stored and delivered from rotating flywheels.
Compressed Air: Compressed air is stored and then passed through turbines to generate electrical energy.
Solid State and Flow Batteries: Both solid state and flow batteries are electrochemical devices that convert stored chemical energy into electrical energy.
Without discussing the pros and cons of each technology mentioned above, this link compares the various energy storage systems.
The renewable-based power systems designed, constructed and operated by WRH Power Systems, predominantly use large battery systems for energy storage. In recent years there have been considerable research and developments for new battery systems with improved energy densities and cycling performance, making battery storage cost effective. WRH Power Systems has working relationships with several large established battery manufacturing companies that have proven battery products with enforceable warranty policies.