Rapid Development of New Energy Storage: “Super Power Banks” Show Their Capabilities
As the energy transition accelerates, the global share of renewable energy has surpassed 30%. This raises important questions: How can we tackle the unpredictability of wind and solar energy? How can we recover and reuse the vast potential energy on offshore platforms and oil drilling rigs? How can we ensure stable electricity supply to homes and factories in underdeveloped areas? The answers to these challenges can be found in new energy storage technologies.
New energy storage refers to technologies that primarily store energy in the form of electricity, excluding pumped storage. Globally, energy storage is often referred to as the “Swiss Army knife” of energy transition, highlighting its versatility, and is also colloquially known as a “super power bank.” In 2024, the development of new energy storage was explicitly mentioned in China’s government work report for the first time. In February 2025, eight departments, including the Ministry of Industry and Information Technology, issued a document to promote the high-quality development of the new energy storage manufacturing sector. But what makes new energy storage so noteworthy? What does it entail, and what are its applications? We sought answers to these questions.
Lithium Battery Storage: Enhancing Grid Flexibility
In the summer of 2024, Jiangsu Province faced a significant test for energy storage during an unprecedented heat wave. The situation was critical, as described by Niu Shubin, vice president of GCL-Poly Energy Holdings. “Due to multiple factors, we faced an urgent situation: Jiangsu experienced its strongest heat wave in 65 years, leading to electricity demand far exceeding expectations. At the same time, the proportion of renewable energy in the Jiangsu grid was rising, surpassing coal for the first time. However, wind and solar energy are inherently intermittent and fluctuate based on natural conditions.”
This means that as the share of renewable energy increases, the security and stability of the power system are increasingly challenged, necessitating improvements in grid adjustment mechanisms represented by new energy storage. As a major manufacturing province, any instability in power supply could severely impact social production and residents’ lives, resulting in immeasurable losses. In response, under a series of policies involving price differences, peak subsidies, and guaranteed usage, several companies committed to completing lithium battery storage projects by July 15. GCL took on 11 projects, leading the charge to ensure supply.
“With only four months to complete the projects, we acted swiftly and set up specialized teams to manage different projects simultaneously, learning from each other’s experiences,” Niu recalled. Thanks to these efforts, all storage projects were completed and operational before the heat arrived. The lithium battery storage stations operated like “super power banks,” charging during off-peak hours and discharging during peak times, successfully ensuring power supply. “The success in tackling the summer peak season can be attributed to the stabilizing role of energy storage,” Niu remarked.
What do these powerful lithium battery storage systems look like, and how do they function? We visited Jiangsu Yuanzheng Energy Technology Company, where lithium batteries are integrated and packaged, undergoing stringent safety tests before being assembled into container-like storage units for system adjustments before delivery. “For our 5 megawatt-hour liquid-cooled storage system, each storage cabinet contains 4,992 batteries,” stated Tian Weiqiang, general manager of Jiangsu Yuanzheng. He explained that these batteries utilize similar materials and processes as those in electric vehicle power batteries, but energy storage places greater emphasis on high safety, low cost, and long lifespan. “To ensure safety and longevity, each battery pack is equipped with liquid cooling, fire safety, battery management, and energy management systems, allowing for real-time monitoring of each battery’s health.”
Tian noted that while power batteries have matured through years of development, energy storage products remain largely customized. “The photovoltaic storage projects we have delivered in Xinjiang and Tibet were tailored to factors like altitude, humidity, land area, and application scenarios.” Additionally, driven by market demand and profitability, Chinese lithium battery storage manufacturers are expanding their horizons overseas. In May 2024, Jiangsu Yuanzheng established a joint venture with South African renewable energy group Veers Group to develop and deploy innovative renewable energy solutions in South Africa. In December 2024, Envision Energy signed a contract with EDF, providing battery storage systems for three projects in South Africa. This same month, Sungrow signed the largest storage system order to date in Southeast Asia with a publicly listed company in the Philippines. In January 2025, GCL was listed among the qualified bidders for a storage project in Saudi Arabia. Notably, Chinese companies account for 90% of the global lithium battery storage shipments.
Compressed Air Energy Storage: Exploring the “Air Power Bank”
In the outskirts of Huanggang, Hubei, eight colossal spherical tanks, each approximately 19 meters in diameter, are neatly arranged. Each tank connects to a 600-meter-deep underground gas storage facility, utilizing natural salt caverns to store 700,000 cubic meters of gas, allowing for an inflow and outflow of 2,880 tons of air per hour, equivalent to the weight of 48 high-speed train carriages. The process of storing and generating electricity occurs through this massive “breathing” action.
How is energy stored in the form of air? Li Jun, a senior management expert at China Energy Engineering Group, provided a vivid analogy: “During off-peak hours, surplus electricity drives a compressor to compress air into a ‘tire,’ creating a high-pressure state.” The “tires” refer to sealed storage facilities such as salt caverns and artificial chambers. The heat generated during the air compression is stored in thermal tanks on the surface as hot water or molten salt. During peak electricity demand, the gas storage facility releases the stored high-pressure air, and the thermal tanks release their stored heat. The high-pressure air is then heated, providing immense expansion force to drive air turbine generators, thereby generating electricity for the grid.
This year, on January 9, China Energy Engineering’s “Energy Storage No. 1,” the world’s first 300-megawatt compressed air energy storage demonstration project, was fully connected to the grid, setting records in single-unit power, storage scale, and conversion efficiency. What does a 300-megawatt single-unit power capacity imply? “We consider ‘Energy Storage No. 1’ as a giant power bank capable of supplying power to an entire small to medium-sized city for five hours,” Li explained. Previously, compressed air energy storage projects had been limited to tens of megawatts, with the highest operational capacity being 60 megawatts in Jiangsu. The 300-megawatt project posed unique challenges in equipment customization and construction that had no precedents worldwide.
Li elaborated on why they opted to tackle such a significant challenge in developing this high-capacity compressed air energy storage project: “To regulate the power fluctuations across an entire regional grid, the energy storage needs to reach a certain scale. Compressed air energy storage offers more flexibility in site selection and shorter construction cycles compared to pumped storage; moreover, a 300-megawatt facility can effectively reduce costs, improve conversion efficiency, and drive upgrades in traditional manufacturing.”
Significantly, most existing salt cavern compressed air energy storage plants require additional fossil fuels to heat the air during electricity generation, a process known as “re-firing,” which inevitably leads to pollution and heat loss. “Energy Storage No. 1” achieved a breakthrough in heat recovery, realizing “non-re-firing” through an internal circulation process that does not require fossil fuels, thus eliminating pollution. “Walking into the facility in Hubei, you will not find any dust; everything is clean.”
“Not only is it pollution-free, but the natural air entering our energy station undergoes temperature and pressure changes, effectively filtering out dust and impurities,” Li Jun noted, likening it to a “large air purifier.” Beyond this, “Energy Storage No. 1” combines multiple technological advancements. Hubei Huanggang is the largest salt reserve base in Central China, with over 40 million cubic meters of underground salt caverns. Previously, water injection was required to maintain pressure balance for geological stability. “Now, we are developing the abandoned cavities left by salt extraction into gas storage facilities,” said Shang Haoliang, technical director of China Energy Engineering Group, adding that this reduces safety risks and maintenance costs while revitalizing a traditional industry.
Natural salt caverns are widely distributed in provinces such as Hubei, Jiangsu, Shandong, Jiangxi, and Yunnan. Traditional gas storage facilities usually adopt a single well-single cavity model, but over 90% of China’s salt cavern resources are horizontally connected and fractured, presenting more complex geological conditions. The successful validation of “Energy Storage No. 1” has significant promotional value, effectively pushing for the re-utilization of over 90% of China’s salt cavern resources. “This is a major breakthrough, akin to awakening dormant resources!” Shang remarked.
In areas with fewer natural salt caverns, experts have explored underground artificial chamber storage and thermal storage solutions utilizing molten salt. In Gansu Jiuquan, another world-first project—a 300-megawatt underground artificial chamber compressed air energy storage project—is currently under construction. The technology route for compressed air energy storage is gradually being established, and in the global trend towards cleaner and lower-carbon energy, the market potential for compressed air energy storage is immense. Li Jun revealed that since connecting to the grid, investors and energy authorities from the US, the Netherlands, and South Africa have expressed interest in “Energy Storage No. 1.” While several countries have conducted related research and practices, China is the first to successfully implement the advanced “non-re-firing” technology in engineering. “In the future, we hope to leverage technology as our core strength to provide comprehensive solutions—including upstream and downstream industrial chains—to the world, making compressed air energy storage a hallmark of China’s green energy,” he stated.
Flywheel Energy Storage: Short-term High Frequency, Voltage Stabilization, and Energy Efficiency
While long-duration high-capacity energy storage is key to energy transition, short-term high-frequency storage also has a wealth of application scenarios. A prime example of this is flywheel energy storage. In Wuhan’s Optics Valley Ecological Corridor, a completely blue train named “Photon” glides smoothly along the track below, resembling a futuristic vehicle from a science fiction movie. Every time the train decelerates to enter the station, an invisible “energy magic” unfolds. During braking, the kinetic energy generated is channeled into the flywheel energy storage system located in the distribution room, where a carbon fiber flywheel rotor spins at an astonishing 36,000 revolutions per minute, converting electrical energy into kinetic energy for temporary storage. When the train resumes motion, the flywheel switches to generator mode, converting stored kinetic energy back into electrical energy to power the train.
This is the world’s first ground-level track using flywheel energy storage for regenerative braking systems. Li Rui, the marketing and sales manager at Shunshi Magnetic Energy Technology Co., Ltd., the developer behind the flywheel energy storage system used in “Photon,” explained, “As an aerial suspended rail, should a power supply system failure occur, the energy stored in the flywheel can help pull the train to the nearest station to evacuate passengers, thus enhancing safety in operation.”
In addition to “Photon,” the flywheel energy storage system developed by Shunshi Magnetic Energy has also been applied in ground railways such as the Beijing Metro’s Fangshan Line and Line 6. The flywheel energy storage system can respond to voltage fluctuations across the rail network within a 20-kilometer radius, enabling continuous and rapid charging and discharging, thereby contributing to energy savings and grid stabilization. “Before the application of flywheel energy storage, the industry typically used resistors to dissipate kinetic energy generated during braking as heat, leading to noise pollution and fire risks,” Li Rui explained. “Later, mid-voltage energy feedback technology was adopted to return the absorbed energy to the AC grid, yielding some energy savings but causing harmonic pollution in the grid, and failing to save costs for users.” After implementing the flywheel energy storage system, data from Shunshi Magnetic Energy indicates that the 1 MW flywheel energy storage system on the Beijing Metro’s Fangshan Line saves approximately 1,500 kilowatt-hours daily, with an average energy saving rate of 23%; voltage fluctuations have also improved from 700–928 volts to 750–900 volts, demonstrating significant voltage stabilization.
Why is flywheel energy storage increasingly applied in rail transit? “First, unlike the more familiar long-duration, large-capacity electrochemical storage systems, flywheel energy storage is a power-type storage, designed for short-term, high-frequency charging and discharging,” Li Rui explained. With high-frequency train services operating every few minutes, the grid experiences frequent fluctuations, necessitating energy storage devices capable of performing hundreds of charge and discharge cycles per hour, which long-duration storage cannot fulfill. Additionally, as a physical storage technology, flywheel storage boasts superior safety. “Among existing storage technologies, flywheel storage is the only one without fire, explosion, or toxic risks, making it more reliable and environmentally friendly.” Li Rui added that unlike many competitors using steel rotors, Shunshi Magnetic Energy’s flywheel products utilize lightweight, high-toughness carbon fiber composite materials and advanced passive magnetic suspension bearings. This allows the flywheel to increase energy storage through speed rather than mass, enhancing response speed, safety, lifespan, installation difficulty, and maintenance, making it particularly suited for rail transit applications.
Beyond rail transit, flywheel energy storage can also be applied in other scenarios with high demands for energy stability, including uninterruptible power supplies (UPS) for data centers to prevent data loss, and recovering gravitational potential energy in oil drilling platforms.
The energy storage industry is currently experiencing rapid growth, with various new energy storage technologies emerging, and different types of “super power banks” are showcasing their unique capabilities. “Every energy storage technology has its applicable scenarios,” Li Rui advised. “The key is to choose the right technology based on the specific scenario.”
