With the rapid development of various energy storage technologies, new energy storage business models have also found new paths.

Driven by the "dual carbon" goal, the energy industry is facing new changes. As an important part of the industry, energy storage temperature control has also ushered in a period of rapid development.

According to data from the Zhongguancun Energy Storage Industry Technology Alliance (CNESA), the newly installed capacity of energy storage projects around the world will basically remain at about 6HW before 2021, and the newly installed capacity will reach 18.3GW in 2021, a year-on-year increase of 181.54%. The new type of energy storage represented by batteries is the main increase in the installed capacity of energy storage. At the same time, according to CNESA data, the newly installed capacity of new energy storage in the world will reach 10.24GW in 2021, a year-on-year increase of 82.8%, and the average annual compound growth rate from 2016 to 2021 will reach 69.11%. As far as the country is concerned, in 2022, the newly installed capacity of new domestic energy storage will be 6.90GW, a year-on-year increase of 182.07%, and the cumulative installed capacity will reach 12.70GW.

"New energy storage" refers to new energy storage technologies other than pumped storage, including new lithium-ion batteries, flow batteries, flywheels, compressed air, etc. These energy storage technologies, including the relatively mature lithium battery energy storage, also have their own advantages and limitations. For the power system, new energy storage can not only improve the regulation ability of the power system, but also ensure the safe operation of the power system. Popularly understood, the new type of energy storage is like a "power bank", which "charges" during low power consumption and "discharges" during peak power consumption. With the continuous growth of fluctuating and intermittent new energy power, the role of "power bank" is becoming more and more obvious. At the same time, the options for new energy "power bank" are gradually diversified.

Electrochemical energy storage is "outstanding"

Although the new energy storage has gradually entered the stage of large-scale development, and the trend of diversification has gradually emerged, but at present, the field of new energy storage still presents the status quo of "thriving" in the field of electrochemical energy storage, and other new energy storage has been coldly received by the market and capital . As the name implies, electrochemical energy storage refers to a variety of secondary battery energy storage that uses chemical elements as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage media. It mainly includes lead-acid batteries, flow batteries, sodium-sulfur batteries, lithium-ion batteries, etc. At present, lithium batteries and lead batteries are the main ones.

Sun Jinhua, a professor at the University of Science and Technology of China and an academician of the European Academy of Sciences, once said that under the background of the "double carbon" national strategic goal and the new energy revolution, the trend of vigorously developing electrochemical energy storage is irreversible.

Why can electrochemical energy storage be "outstanding"? The cost of batteries has been accumulated over a long period of time and technological innovation is a major reason for the faster development of electrochemical energy storage compared with other new energy storage. In addition, the global battery industry is developing rapidly. Under the environment of high demand, the battery industry is also ushering in its own golden age. "Electrochemical energy storage has a higher energy density, and the supporting industry chain is more mature." According to Cui Jian, executive vice president of Xiamen Kehua Digital Energy Technology Co., Ltd., the reason why other new types of energy storage are coldly received by the market and capital is that in In terms of scenario application, technology, cost, construction period, conversion efficiency and site selection requirements, electrochemical energy storage has more advantages, with high flexibility, safety and cost performance.

Even more mature electrochemical energy storage also needs to pay attention to safety issues. In September last year, a fire broke out at the Elkhorn Substation in Monterey County, California, USA. The fire was caused by Tesla's energy storage system Megapack. From the perspective of electrochemical energy storage projects around the world, the fire accident of the Tesla Megapack energy storage system is not an isolated case. According to incomplete statistics, as of September last year, there have been more than 60 electrochemical energy storage fire accidents in the world. Most of the energy storage batteries use ternary lithium batteries. The accidents occurred mainly during the equipment debugging stage and after charging and discharging. At rest. How to ensure safety and stability is a major problem that needs to be solved urgently in the development of electrochemical energy storage. It is generally believed in the industry that the safety management of electrochemical energy storage power stations in the future should cover the entire life cycle, and build a triple line of defense for body safety, active safety, and fire protection. In this regard, Sun Jinhua proposed that in terms of battery development, research and development of flammable and non-combustible battery materials should be used to build the first line of defense for the body safety battery system; in terms of battery applications, multi-signal fusion and early warning based on thermal runaway models should be used to ensure battery safety. The second line of defense in the use of process safety; in terms of fire disposal, multiple fire extinguishing technologies have been developed to suppress battery re-ignition and form the third line of defense in fire safety.

New Breakthrough in Compressed Air Energy Storage System

When lithium-ion batteries occupy a dominant position in the field of stationary energy storage, more and more industrial enterprises are actively developing different technologies to enhance their own competitiveness and bring more competitive energy storage systems to the market. Among them, compressed air energy storage is especially suitable for supporting energy storage needs in a longer time dimension in the future, adapting to the characteristics of high penetration rate of new energy in new power systems, and even reaching daily or quarterly energy storage needs.

On May 30, at the 2023 Zhongguancun Forum, the world's first 100-megawatt advanced compressed air energy storage demonstration system was unveiled. This technology has achieved a qualitative leap from 10 megawatts to 100 megawatts of advanced compressed air energy storage, which is another powerful tool for the development of long-term large-scale energy storage technology in my country. Advanced compressed air energy storage system is a multi-disciplinary and multi-process coupling system, covering more than ten disciplines such as engineering thermodynamics, fluid mechanics, heat transfer, power system and automation, as a typical long-term large-scale energy storage technology , can realize large-scale development and utilization of wind power, photovoltaic and other renewable energy. To put it simply, its principle is to store the compressed air and let the compressed air drive the generator to work when power generation is needed.

According to Xu Yujie, director of the Energy Storage Research and Development Center of the Institute of Engineering Thermophysics, Chinese Academy of Sciences, my country's future power system will be a new type of power system with new energy as the main body, while wind power, photovoltaic power generation and other renewable energy power generation is volatile and intermittent. If it is connected to the grid on a large scale, it will cause security risks. At this time, the energy storage system is needed as a flexible adjustment resource to adjust the power system. Compressed air energy storage is a highlight.

"Compressed air energy storage technology is not new. Traditional compressed air energy storage technology has been used in Germany and the United States for many years. However, traditional compressed air energy storage technology has problems such as dependence on fossil fuels, large natural caves, and low energy storage efficiency. Scale promotion has always been limited." Xu Yujie said that my country's advanced compressed air energy storage system recycles compression heat, no longer uses fossil fuels, and can use various forms of storage such as above-ground gas storage devices, artificial chambers, and underground natural caves. Air chamber. In addition, the system greatly improves energy storage efficiency.

What are the advantages of compressed gas energy storage over other new types of energy storage? Overall, it can be summarized as three points: safety, longevity, and strong explosive power. Compressed gas energy storage is first and foremost very safe. Take the liquefied carbon dioxide energy storage project as an example. Because carbon dioxide is easy to liquefy, it only needs a few megapascals of pressure to store it. There is no need to worry about hidden dangers caused by high-pressure gas storage. At the same time, carbon dioxide is non-toxic, non-flammable and explosive, and its own safety Just fine. In addition, because they are all mechanical devices, the service life of the compressed air energy storage system can reach 30 to 50 years under normal maintenance conditions. "Compressed air energy storage is a physical process based on thermodynamic cycles, which has natural advantages in terms of safety and performance attenuation, and is considered to be one of the most promising large-scale energy storage technologies." Based on these advantages, the Institute of Engineering Thermophysics, Chinese Academy of Sciences Researcher Chen Haisheng once said that the application of compressed air energy storage technology has great strategic significance and huge market demand for the realization of the national "double carbon" strategic goal and the improvement of the natural environment.

It is worth mentioning that the energy explosive power of compressed air energy storage is relatively strong. This can lead directly to some interesting applications. In the case of diesel engines used in large ships, for example, compressed air is usually stored in a pressure tank and acts directly on a piston through a special priming valve to turn the crankshaft before fuel injection begins. This arrangement is more compact and less expensive than an electric starter motor of the same size, and is able to provide the necessary bursts of extremely high power without placing excessive loads on the ship's generator and electrical distribution systems.

For compressed air energy storage systems, large-scale demonstration and application should be further strengthened in the future, experience in engineering design and construction should be accumulated, and a complete and mature industrial chain should be developed to further accelerate its construction and application.

Shared energy storage blooms everywhere

With the rapid development of various energy storage technologies, new energy storage business models have also found new paths. The pressure of new energy consumption and power grid peak regulation is becoming more and more serious, which brings challenges to the safe and stable operation of the new power system. In the past two years, shared energy storage has emerged as a new force. It has become an important way to promote the high-quality development of new energy allocation and energy storage due to its advantages such as more efficient dispatching and operation, more prominent economic benefits, and sustainable operation paths.

Shared energy storage is essentially a centralized large-scale independent energy storage power station invested and constructed by a third-party investor. In addition to meeting the needs of its own power station, it also provides services for other new energy power stations; the power station through bilateral negotiations, bilateral bidding and Participate in power transactions through unilateral call and other modes, reduce the waste power of new energy stations, and participate in the power auxiliary service market. Under the shared energy storage model, the owner does not need to bear the cost of building the energy storage power station, but only needs to pay the lease fee every year, which is conducive to reducing the one-time capital expenditure and relieving the financial pressure; third-party shared energy storage investors need to undertake the construction of energy storage For the cost of the power station, the source of income is the stable rental fee. If the income from the peak-shaving auxiliary service is considered, the economy is better and the income is considerable.