7 Energy Storage Technologies You Should Know About

Energy storage is the key to unlocking renewable energy and removing the grid limitations of solar and wind. Energy storage helps utilities and grid operators manage peak demand, prevent blackouts, reduce CO2 emissions, and integrate renewables. Electricity cannot be stored in a straightforward way like water in a tank or oil in a barrel; there are many more complex ways of storing it that involve conversion into another form of energy (e.g. thermal energy) or using other methods such as mechanics, electronics, and chemistry. When we say that electricity is stored in an object or device, what we really mean is that it is being stored as another type of energy. There are several ways to do this: Thermal storage, mechanical storage, chemical storage, pumped hydro storage and battery storage are among the most common types of energy storage used today. Here are 7 different types of energy storage

Energy storage is the process of converting energy from one form into another, and then back again later. When we use energy, we use it in a certain form, for example as thermal or electrical energy. A battery converts chemical energy into electrical energy and back again when we use it. The same is true for a hydroelectric dam, which converts gravitational potential energy into kinetic energy and back again when we use it. While most energy sources have a finite amount available, energy storage enables us to use them at any time, as needed. Energy storage is often used in combination with other technologies. For example, a wind farm can be paired with a battery to store the energy generated by the turbines at times when it is not needed, and then distribute that power when it is needed. Similarly, large-scale solar power plants can store excess energy generated during the day by heating a fluid with solar-thermal collectors and then using that fluid to generate electricity after sunset.

Thermal energy storage (TES) is the conversion of thermal energy into potential energy. A thermal store is a device that contains a fluid that can be heated or cooled to store thermal energy for later use. A thermal store may be used for thermal energy conversion and energy storage. There are many applications for thermal energy storage, including electricity generation, district heating, process energy, and desalination. Thermal energy can be stored in a variety of materials, including water, salt, concrete, soil, gravel, fly ash, and sand. Thermal energy storage is an important technology for managing renewable energy. It can be used to store solar energy in the form of heat or to store heat generated by solar, geothermal, or wind power. It can also be used for cooling, especially in places where there is a large amount of waste heat, such as electricity-generating plants. TES systems typically have low capital costs and can have low operation and maintenance costs if the design and operation are well planned.

Mechanical energy storage involves storing energy in the form of mechanical motion, such as in a rotating shaft or a compressing substance. Examples of such systems include hydropower plants (converting water flow into rotational energy), flywheels (converting kinetic energy into rotation), compressed air energy storage (converting excess electricity into compressed air), and pumped water storage (converting kinetic energy into gravitational potential energy). Mechanical energy storage is a technology that is still in the developmental stages. There are only a few commercialized systems, and mostly they are in the research and development phase. One advantage of this method of energy storage is that it is modular, and a range of different types of energy can be stored: kinetic, potential, or chemical. One drawback is that mechanical energy storage systems tend to be large, heavy, and have high upfront costs.

Chemical energy storage uses chemical reactions to store energy. Examples include hydrogen production by the electrolysis of water and the production of methane by biomass conversion. The main advantage of chemical energy storage is that the storage materials are cheap and widely available. The main drawback is that the efficiency of the process is very low, and so large quantities of chemicals are needed to store enough energy for practical applications. Another drawback is the safety of these chemicals, which requires appropriate safety measures during production and storage.

Pumped storage is a type of hydroelectricity storage whereby a surplus of electric power is used to pump water from a lower reservoir to a higher reservoir. Later, when energy is needed, water is allowed to flow back through the system, spinning turbines as it goes, and generating electricity. The upper reservoir is usually a natural lake or river. This technology has been used since the early 20th century, and almost 60% of the world's installed hydroelectric power is used for pumped-storage hydroelectricity. The lower reservoir is usually a natural aquifer, an artificial reservoir, or a combination of both. This technology is most suitable for areas that have a large amount of cheap electricity but need a reliable level of electricity later. Pumped hydroelectricity is the most common type of large-scale energy storage worldwide, and the investment cost per unit of electricity stored is significantly lower than any other type of energy storage. Any excess power generated by a power plant can be used to pump water from a lower reservoir to an upper reservoir. Later, when there is less demand for power, the water can be allowed to flow back down through the turbine-driven pumps, generating electricity as it goes.

Battery storage, in its simplest form, involves using rechargeable batteries to store excess electricity when it isn't needed. This can be useful for people who live in areas where there is a lot of intermittent solar or wind power. It can also be used as a grid-scale energy storage method in areas with high carbon emissions, where there is a large amount of coal-burning power plants. In these areas, battery storage can help reduce harmful emissions that cause climate change by helping the grid operators balance supply and demand. Grid-scale batteries are also more efficient and less expensive than they have ever been. There are many different battery types that may be used for energy storage. For example, vanadium flow batteries, lithium-ion batteries, sodium-sulfur batteries, and lithium-metal batteries. Batteries have a higher upfront cost than other types of energy storage, but they are cheaper over the long term. They have the advantage of being modular, which means they can be built in any size – from small, residential systems to large utility-scale systems.

Electrical field storage (EFS) is a technology that stores energy in the form of an electrical field. It can be used for various grid balancing applications, such as frequency regulation, energy shifting, and energy arbitrage. There are two types of EFS: electrostatic and electromagnetic. Electrostatic EFS is widely used for frequency regulation applications, where it is commonly referred to as “static VAR”. It is commonly used with natural gas turbines for peaking power but can be used with any type of generation. Electromagnetic EFS is widely used for energy shifting, where it is commonly referred to as “VCIG”. It is being used in islanding applications, but can also be used for grid balancing applications. Both technologies have a low upfront cost but have lower efficiency than other types of energy storage.

Energy storage is a key technology that enables a transition to a low-carbon energy system. It plays a critical role in integrating high shares of variable renewable generation (such as solar and wind), by providing grid reliability, grid stability, and energy security. Energy storage technologies have been rapidly maturing, and costs have been decreasing, making them increasingly competitive with other generation sources for meeting energy demand. Existing generation sources, such as fossil fuel and nuclear, are also becoming more flexible, enabling them to better integrate with variable renewable generation.