FreeWord – Energy Storage

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Hello folks! It’s time to dig into the world of Energy Storage!

One of the primary goals of the sustainable energy revolution is to provide clean, affordable, accessible energy with minimal environmental impact. As of today, energy storage plays an essential role in the development and integration of renewable energy technologies. Over the last few years, there has been a significant increase in power generation, especially from photovoltaics (PV) and wind turbines, which have lead energy storage into the spotlight. By optimizing energy storage, we can achieve more efficient, effective, and reliable power consumption.


The electricity grid is a complex system in which power supply and demand for energy must be equal at any given moment. Continuous supply adjustments are needed to create a balance due to people’s consumption, equipment overload, weather changes, etc. Energy storage plays a vital role in helping to create a more flexible and reliable grid.

In addition, energy storage is also valued for its rapid response – most storage technologies can discharge power into the grid very quickly, which is important for ensuring the stability of the grid when unexpected increases in demand occur. The further from the energy grid you are located, the more critical energy storage also becomes since you must rely on the stored energy in the batteries.

Storage Types

energy storage types

Energy storage systems are a set of methods and technologies used to store various forms of energy. There are many forms of energy storage. The most important ones are listed below.

– Solid-State Batteries

Due to their size and weight, solid-state batteries can be located anywhere, e.g. cell phones. Solid-state batteries can be deployed on a large scale as well, since they are often seen as storage for distribution when a battery facility is located near consumers to provide power stability, or end-use, like batteries in electric vehicles. There are many different types of batteries that have large-scale energy storage potential based on the used material, such as sodium-sulfur, metal-air, lithium-ion, and lead-acid batteries.

– Flow Batteries

Batteries where the energy is stored directly in the electrolyte solution enabling longer charge/discharge cycles. Usually four hours each.

– Flywheels

Flywheels can provide a variety of benefits to the grid at either the transmission or distribution level, by storing electricity in the form of a spinning mass. Flywheel energy storage functions by accelerating a rotor to high speed and maintaining the power as rotating energy. When that energy is extracted from the system, the flywheel’s rotational speed decelerates and subsequently accelerates when energy is reintroduced. Flywheels typically have long lifetimes, require little maintenance, provide high efficiencies and rapid response times.

– Pumped Hydro-Power

Create energy reserves by using gravity and the manipulation of water elevation by storing excess generation for later use. Many hydroelectric power plants include two reservoirs at different elevations. These plants store energy by pumping water into the upper reservoir when supply exceeds demand. When demand exceeds supply, the water is released into the lower reservoir by running downhill through turbines to generate electricity.

– Compressed Air

Compressed air energy storage (CAES) plants are similar to pumped hydropower plants; only instead of pumping water from a lower to an upper pond, ambient air is compressed and stored under pressure in underground caverns to store energy. When that energy is required, the pressurized air is heated and expanded in a turbine, thus driving a generator for power production.

We have become much more bullish about storage deployments since our last forecast a year ago. This is partly due to faster-than-expected falls in storage system costs, and partly to a greater focus on two emerging applications for the technology – electric vehicle charging, and energy access in remote regions.

Yayoi Sekine, an energy storage analyst for BloombergNEF


As new energy storage technologies are being researched and tested, batteries in the future are predicted to be a lot smaller, safer, lighter, and more efficient. Hopefully, they’ll also come from more sustainable materials than traditional lithium-ion batteries which require precious metals. Currently, there are interesting emerging battery technologies that could disrupt the market.

Below is BNEF’s forecast for global deployment of behind-the-meter and grid-scale batteries over the coming decades. 

energy storage forecast


Given the current global situation, advances in battery storage technologies are inevitable. With more intermittent resources on the grid, the need for support capacity increases. The global effort to reduce carbon dioxide emissions requires continuous improvements in battery storage technology.

Advancements in battery technologies have been made, which is largely due to the expanding EV, solar, and wind industry. As more developments are made, more battery costs continue to decline. Electric vehicles and renewable energy sources could also have an impact on energy storage through vehicle-to-grid technologies (V2G), which enable EV to store and discharge electricity from the grid.

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