There are various storage solutions available today and the most prominent ones are either thermal, batteries or mechanical systems. These solutions are connected with software that control the charge and discharge of energy.
Below is a list of the most common energy storage solution being used in various industries.
Batteries are most common form of energy storage. We use batteries in almost all the electrical devices around our house. There are various types of batteries, including: Flow, Lithium-ion, sodium, acid and other type that made for specific duration and power requirements.
Lithium-ion batteries were first used as a consumer product but now have a range of uses including, smaller residential systems and bigger systems that can support the entire grid with storage of multiple MWh(megawatt hours)
These large systems generally have a couple of batteries that are stacked together with management and monitoring units as well. The footprint of these storage devices is quite minimal when compared to the energy stored. A battery system the size of a small fridge can power an average household for a week or more.
Lithium batteries are gaining traction because they are used in electric vehicles as well and the cost of lithium ion batteries are declining.
If you are looking for longer storage duration, then you might want to look at flow batteries. Aggreko power solutions have various type of battery storage solutions.
These storage solution system release and store energy using heating and cooling methods. An example is molten salt which stores heat that is solar-generated to be used later when there is no sunlight. Another is ice storage in commercial building that reduces the need for compressors but still manages to provide air conditioning for several hours. They are various other systems that uses dispatchable hot water boilers and chilled water too.
There are two main types of mechanical systems: Flywheels and Pumped Hydro Power.
This type of system stores energy in a mechanical rotor that is rapidly spinning. The rotor is mainly used for short bursts of high energy last for around 15 minutes or less. However longer duration flywheels are being developed.
Flywheels are used to balance electricity fluctuations between demand and supply. This is done using a control signal which is adjusted every few seconds. They are also used in energy dependent manufacturing processes where a power outage could cause a loss in productivity.
Pumped Hydro Power
The most common form of energy storage on electrical grids is hydroelectric facilities. They account for around 95% of the energy storage nowadays. Using excess energy turbines are used to pump water to a reservoir that are elevated and when demand for energy is high the reservoirs are open and the water flows from an elevation through turbines and produces electricity. The footprint is quite large with this type of storage system.