As of my last update in September 2021, there are several types of electrical energy storage systems (ESS) that are used to store electricity for later use. These systems are essential for integrating renewable energy sources, improving grid stability, and meeting peak electricity demands. Here are some of the most common types of electrical energy storage systems:
Battery Energy Storage Systems (BESS): Batteries are the most widely used ESS technology. They store electrical energy in chemical form and can release it when needed. Various types of batteries are used for energy storage, such as lithium-ion, lead-acid, sodium-sulfur, and flow batteries.
Pumped Hydro Storage: This is one of the oldest and most proven methods of energy storage. It involves using excess electricity to pump water from a lower reservoir to a higher one. When electricity is needed, the stored water is released, flowing back down through turbines to generate electricity.
Compressed Air Energy Storage (CAES): CAES systems store energy by compressing air and storing it in underground caverns or tanks. When electricity is needed, the compressed air is released and expanded through turbines to generate electricity.
Flywheel Energy Storage Systems: Flywheels store energy by spinning a rotor at high speeds and maintaining its kinetic energy. When electricity is needed, the spinning rotor's energy is converted back into electrical power.
Thermal Energy Storage (TES): TES systems store energy in the form of heat or cold. One common method is using molten salt or other phase change materials to store heat, which can later be used to generate steam and produce electricity.
Superconducting Magnetic Energy Storage (SMES): SMES systems use superconducting coils to store electrical energy in the form of a magnetic field. When electricity is needed, the stored magnetic energy is converted back into electrical power.
Hydrogen Energy Storage: This involves using electricity to produce hydrogen through water electrolysis, storing the hydrogen, and then converting it back to electricity through fuel cells when needed.
Electrochemical Capacitors (Supercapacitors): Supercapacitors store energy electrostatically and can deliver high power output for short durations. They are often used in combination with batteries to provide quick bursts of energy.
Gravitational Energy Storage: This concept involves using large weights or systems like "energy towers" to store potential energy, which can be released to generate electricity.
Please note that technology and research in the field of energy storage are continually evolving, and new types of energy storage systems may have emerged beyond my last update.