There are many forms of energy storage, and the technologies used are quite diverse. Different energy storage technologies  are suitable for different application scenarios.

As the name suggests, energy storage refers to the process of storing energy in some form and releasing it when needed. The main purposes of energy storage are to improve energy efficiency, balance supply and demand of energy, stabilize the grid, and promote the development of renewable energy.

Following global net-zero plans, renewable energy is growing rapidly. It is expected that by 2050, renewable energy will account for more than 75% of global energy^note1. However, the intermittent nature of renewable energy can lead to power shortage or energy waste. Energy storage technology, such as the widely deployed lithium battery storage systems, can be used to shave peaks, thereby addressing the intermittency of renewable energy.

There are many forms of energy storage, and the technologies used are quite diverse, including mechanical energy, electrochemical energy, electromagnetic energy, thermal energy, and chemical energy. Different energy storage technologies have their own advantages and disadvantages and are suitable for different application scenarios. For example, pumped hydro storage is suitable for large-scale, long-duration storage, while battery storage is suitable for fast response and flexible dispatch, and is currently the mainstream form of electrochemical energy storage.

Here are some major emerging energy storage technologies:

Sodium battery and solid-state battery
In addition to lithium battery, some emerging energy storage technologies such as sodium battery and solid-state battery are being developed rapidly. The advantages of sodium battery include abundant reserves, better safety and better environmental performance than lithium battery, and its better low-temperature performance makes it particularly suitable for low-temperature storage applications. The cost after mass production is also lower. It is currently estimated that sodium battery will account for about 15% of the global energy storage market by 2035^note2. Solid-state battery has the advantages of high energy density and high power, making them particularly suitable for power battery. According to a report by EO Intelligence in November 2024^note3, as solid-state battery technology matures and cost decreases, it is expected to be gradually applicable to cost-sensitive energy storage scenarios after 2033.

Long-duration energy storage technologies
On the other hand, as the proportion of renewable energy increases, many international organizations are calling for the necessity of long-duration energy storage technologies (≥ 6 hours of power supply). The International Energy Agency believes that by 2035, with renewable energy accounting for 50-75%, long-duration energy storage will be ubiquitous^note4. Although lithium battery can also be used for long-duration energy storage, the overall cost of lithium battery storage will increase significantly as the required power supply duration increases.

According to technical classification, long-duration energy storage technologies can be divided into four categories. The first category is mechanical storage, such as gravity storage and compressed air storage; the second category is thermal energy storage, such as sensible heat storage, latent heat storage, and thermochemical energy storage; the third category is electrochemical storage, such as vanadium redox flow batteries and iron rust batteries; the fourth category is chemical storage, such as hydrogen energy. Most long-duration energy storage technologies are still in the research and development stage, but a few have demonstration projects or are even close to commercialization, such as iron-air battery. Besides hydrogen energy, the most widely deployed technologies globally are thermal energy storage, compressed air storage, and vanadium redox flow battery.

In terms of time, long-duration energy storage technologies are mainly used for storage needs of several days, weeks, or even seasonal storage, such as snow for a week to several weeks, storms for several days, and areas with short daylight in winter. In terms of applications, long-duration energy storage is mainly used for long-term energy transfer of renewable energy, providing stability for island microgrids, or assisting industrial and commercial enterprises in signing 100% renewable energy power purchase agreements. Additionally, large electricity customers or industrial areas far from the grid can also use long-duration energy storage to ensure a stable power supply.

With the energy transition and the development of renewable energy, the importance of energy storage is also receiving more attention. Global adoption of renewable energy (such as solar and wind energy) is increasing, and the demand for energy storage solutions is also increasing in order to balance the intermittency of renewable energy and ensure grid stability. To improve energy security, governments around the world are turning to support the development and deployment of energy storage technologies, hence uplifting technological advancements. As technology improves, costs decrease, and market demand for grid flexibility and reliability increases, these factors will promote the growth of the energy storage market.

According to a report by market research firm Precedence Research^note5, the global energy storage market will show a steady growth, with the market size growing from US$44.7 billion in 2022 to US$167.9 billion in 2032, with a compound annual growth rate of 14.20%. This indicates that the energy storage market has huge growth potential.

Note 1: IEA report：https://www.iea.org/reports/net-zero-by-2050 
Note 2:BloombergNEF https://about.bnef.com/ 
Note 3:https://www.iyiou.com/research/ 
Note 4:IEA report：https://www.iea.org/reports/integrating-solar-and-wind 
Note 5:Precedence Research : https://www.precedenceresearch.com/