As the world is facing energy outages with rising demand, the importance of finding and developing alternative energy sources has been increased. Alternative energy is shortly defined as energy production from any source other than fossil fuels. Undoubtedly, another reason for the tendency to use renewable energy sources has been to remain loyal to the Paris Climate Agreement and reduce carbon emissions. However, since renewable energy sources cannot always meet the energy needs due to weather conditions, etc., they are not considered reliable sources. Therefore, investments in renewable energy resources do not take up as much as fossil fuels. To increase the reliability of renewable energy sources and reduce dependence on fossil fuels, initiatives are attempted to develop energy storage systems technology.
Energy storage is simply gathering energy at one moment and storing it for later use. With energy storage technology, energy can be stored in various forms (chemical, kinetic, or thermal) and then converted back to useable forms of energy like electricity. While the amount of energy generated must be equal to the amount of energy consumed conventionally, energy storage enables us to alter the old system by its property of mediating between variable sources and variable loads. Also, energy storage is a tool to improve the stability of transmission and distribution of energy, which is another serious challenge of supplying energy for all in a sustainable way.
Energy storage technologies have many benefits, such as reducing imbalances between energy demand and production increasing the possibility of supplying and reaching energy whenever or who needed. Furthermore, it increases the reliability and flexibility of renewables. As renewable energy sources are used more, it implicitly helps in remedying environmental impacts. Another advantage of energy storage technologies is potentially integrating diverse energy sources. The storage of energies produced from different sources will enable different energy production methods to support each other. This is an important step to increase efficiency in energy generation. A drawback or open question side of the energy storage technologies is whether they supply sustainability and cost-effectiveness fully or not. That could be answered with long-term plan analyses, and the analyses vary by energy storage methods.
Nowadays, a variety of energy storage technologies, such as pumped hydroelectric storage and battery systems, are already in use. Pumped hydro accounts for nearly all present energy storage capacity and stores energy as gravitational energy when water is pumped from low elevations to higher elevations. To generate electricity, water is run down through hydroelectric turbines. While pumped hydro is capable of storing high energy and power capacity, it requires special locations and is expensive to build.
Batteries are another storage technologies that store energy chemically. The deployment of battery systems is quickly increasing with the benefits of flexibility and convenient sizing. However, they may not be ideal for environmental sensitivity and are appropriate for applications that need quick energy discharge and absorption.
Another type of energy storage technology is compressed air energy storage which compresses air and then stores it, usually in an underground cavern. To generate electricity, compressed air is released and utilized to power a turbine. On the one hand, the system features a high power-rating, plenty of storage, and a long lifespan; on the other hand, it requires special underground locations and a high investment amount to build and maintain them. Flywheels, supercapacitors, thermal energy storage, and hydrogen are the other storage technologies at the demonstration or pre-commercial stages.
The development of storage technologies is rapidly gaining importance all over the world. European Commissionunderlines the key role of developing energy storage technologies by showing a fact from a German study that today's one-hour inaccuracy in forecasting oncoming wind causes an additional demand for 5 to 7 GW of electricity. The commission expresses the goal to be achieved as follows: ” While gas power plants will be able to produce demanded electricity within an hour or two, energy storage has to deliver during this gap of time.” According to Energy Storage News, the United States also has been revived potential motivations for future support of storage technologies. Mostly, the energy storage bonus (a kind of cash grant) and investment tax credits have been provided as subsidies. In Turkey, at the beginning of 2022, Kontrolmatik Technology has invested in lithium battery cells and energy storage systems, which will reach a total capacity of 1,000 MW hours when completed. We will certainly hear more about such initiatives in energy storage systems technologies in the near future, both in our country and globally.