Main types of energy storage

The transition to renewable energies has opened up opportunities with respect to energy storage, a set of technologies that is beginning to gain strength as an ally of clean energies.

Energy storage systems allow the use of a greater amount of renewable energy. This implies cost reduction, since renewable energies are cheaper.

Although batteries are the oldest method for storing energy in small doses, today there are other storage systems, among which we can find the following:

1. Large-scale storage (reversible hydro (pumped hydro) and thermal storage) which is employed with GW scales.
2. Storage in grids and generation assets (batteries, capacitors, superconductors and flywheels) where MW scales are used.
3. End-user level storage (batteries, superconductors and flywheels) which is used with kW scales.

Storage technologies 

1. Hydroelectric pumping

It is a technology that provides stability to the electrical system, generating large amounts of clean energy with shorter response times than other technologies. Its installations allow an improvement in the economic efficiency of power system operation by storing electricity in the form of water dammed in a reservoir.

2. Compressed air

This is a storage system in which its installations have a reversible engine that stores air at high pressures in underground cubicles. The energy generated during periods of low demand can be released to supply periods of higher demand.

3. Thermal storage

Consists of accumulating energy in instruments that allow it to be retained and released gradually, through systems that range from refrigeration through ice accumulation to exposure to high temperatures.

4. Supercapacitor

It is based on the use of devices to store energy in the form of an electric field and are capable of storing large amounts of electrical energy and can be charged and discharged in just seconds, thus making them ideal for responding to brief interruptions in supply.

5. Flywheels

These are mechanical devices that store by means of the principle of rotating mass and emulate the storage of electrical energy by converting it into kinetic energy and then converting it back into electrical energy.

6. Batteries

Energy storage systems that employ electrochemical processes and have the capacity to return energy almost in its entirety. There are a variety of types, such as lead-acid, lithium-ion or nickel-cadmium batteries. They have several benefits such as their fast response time and ease of installation.

7. Hydrogen fuel cells

It is an energy storage system that uses electrochemical processes. It differs from batteries in that hydrogen supplies the battery from the outside, allowing it to be used constantly.

Our world is in a transition from fossil fuels to renewable and clean energies, so an improvement in electrical energy storage is of vital importance to support these technologies.