Abstract
It is a significant strategic decision made by the CPC Central Committee and The State Council to strive for achieving carbon peaking and carbon neutrality, as well as building a clean, low-carbon, safe, and efficient energy system. New energy storage plays a pivotal role in supporting the realization of these “dual carbon” goals. It is not only a crucial means to ensure energy supply security but also a key element in constructing a new power system. Furthermore, it represents an important direction for cultivating strategic emerging industries, holding promising prospects for development. This article aims to analyze and compare the technical characteristics and application scenarios of the main technology routes for new energy storage. Based on this analysis, the future development trends of new energy storage are also prospected.
1. Overview of New Energy Storage Development
New energy storage refers to technological means primarily functioning to generate electricity, excluding pumped hydro storage. It serves as a fundamental technology and essential equipment for building a new power system. With the increasing demand for regulation capabilities in the power system and the continuous expansion of renewable energy development and consumption, the new energy storage industry has exhibited rapid development. The new energy storage market is moving towards scale, ushering in a period of high-speed growth. The technology routes play a supporting and leading role in the development of new energy storage, making research on these routes highly significant.
2. Main Technology Routes for New Energy Storage
New energy storage can be broadly categorized into electrical energy storage, hydrogen energy storage, and thermal energy storage. Below is a detailed analysis of each category.
2.1 Electrical Energy Storage
Electrical energy storage can be further divided into electrochemical energy storage, mechanical energy storage, and electromagnetic energy storage.
Table 1: Comparison of Various Typical Electrical Energy Storage Technologies
| Category | Storage Type | Response Time | Discharge Duration | System Efficiency | Lifespan | Energy Density | Investment Cost | kWh Cost | Application Scenarios |
|---|---|---|---|---|---|---|---|---|---|
| Electrochemical | Lithium-ion Battery | ms~minutes | ms~hours | 80%~90% | 5000~10000 cycles | 200~400 Wh/L | 987~1250 ¥/kWh | 0.40~0.65 ¥/kWh | Peak shaving, frequency regulation, energy management, backup |
| Flow Battery | ms~seconds | hours | 70%~80% | 10000~16000 cycles | 20~70 Wh/L | 2500~3000 ¥/kWh | 0.71~0.95 ¥/kWh | Peak shaving, frequency regulation, energy management, backup | |
| Lead-carbon Battery | ms~minutes | ms~hours | 80%~85% | 2000~4000 cycles | 50~80 Wh/L | 800~1000 ¥/kWh | ~0.56 ¥/kWh | Peak shaving, frequency regulation, backup power for communication base stations | |
| Sodium-ion Battery | ms | seconds~hours | 80%~90% | 1500~4000 cycles | 150~300 Wh/L | 3000~4000 ¥/kWh | 0.67~0.88 ¥/kWh | Peak shaving, frequency regulation, energy management, backup | |
| Mechanical | Compressed Air Energy Storage | minutes | hours~days | 40%55% (traditional); 60%75% (new) | >30 years | 2~6 Wh/L | 800~1500 ¥/kWh | 0.2~0.40 ¥/kWh | Peak shaving, backup, black start |
| Flywheel Energy Storage | ms | ms~minutes | 90%~95% | ~20 years | 20~80 Wh/L | ~11000 ¥/kWh | – | Frequency regulation, smoothing fluctuations | |
| Gravitational Energy Storage | seconds | hours | >85% | 30~35 years | – | 3500~4500 ¥/kWh | ~0.5 ¥/kWh | Demand response, peak shaving, frequency regulation | |
| Electromagnetic | Supercapacitor Energy Storage | ms | ms~minutes | 70%~90% | 100000 cycles | 10~20 Wh/L | 10000~15000 ¥/kWh | – | Frequency regulation, smoothing fluctuations |
| Superconducting Energy Storage | ms | ms~seconds | >90% | >30 years | 6 Wh/L | – | – | Frequency regulation, smoothing fluctuations |
2.1.1 Electrochemical Energy Storage
- Lithium-ion Battery Storage: Lithium-ion batteries are the most widely used technology in new energy storage, with high energy density, moderate response speed, and a wide range of applications. They are easier to mass-produce, install, and maintain.
- Flow Battery Storage: China’s flow battery technology has reached international leading levels, with large-scale vanadium redox flow battery technology achieving preliminary industrialization.
- Lead-carbon Battery Storage: Lead-carbon batteries are cost-effective, have good high-rate discharge performance, and excellent temperature performance, making them suitable for various renewable energy storage systems.
- Sodium-ion Battery Storage: Sodium-ion batteries can be applied in load frequency regulation, grid peak shaving, renewable energy integration, and improving power quality.
2.1.2 Mechanical Energy Storage
- Compressed Air Energy Storage: It has advantages such as large installed capacity, long energy storage time, short construction period, long service life, and cleanliness. It is suitable for promoting large-scale renewable energy integration and meeting peak shaving demands.
- Flywheel Energy Storage: It has instantaneous response, precise tracking, and bidirectional output capabilities, with significant technical advantages in grid frequency regulation. However, it requires innovations and breakthroughs in system capacity, conversion efficiency, service life, and safety.
- Gravitational Energy Storage: It is an emerging energy storage technology, currently mainly in the form of energy storage towers. It is in the early stages of engineering demonstration.
2.1.3 Electromagnetic Energy Storage
- Supercapacitor Energy Storage: It can release a large amount of electrical energy in a short time, suitable for short-term, high-power load smoothing and peak power scenarios in power systems.
- Superconducting Energy Storage: It has high efficiency, high power density, fast response speed, and unlimited cycles. However, it is expensive and complex to maintain.
2.2 Hydrogen Energy Storage
Hydrogen energy storage is one of the potential application areas of hydrogen energy, featuring long-term energy storage and long-distance transportation potential. It can be categorized into high-pressure gaseous hydrogen storage, liquid hydrogen storage, and solid-state hydrogen storage.
2.3 Thermal Energy Storage
Thermal energy storage can be divided into sensible heat storage, latent heat storage, and thermochemical heat storage.
- Sensible Heat Storage: It is technically mature, simple to operate, environmentally friendly, and low in cost. It is mainly used in concentrated solar power generation, clean energy heating, and thermal power flexibility retrofits.
- Latent Heat Storage: It has high energy density and a nearly constant temperature during the phase change process. It is applied in power peak shaving and renewable energy consumption fields.
- Thermochemical Heat Storage: It has greater energy storage density and can store thermal energy losslessly at room temperature for extended periods. It is mainly used in industrial waste heat recovery, building heating (heat pumps), and thermal power generation.
3. Comparison of Main Technology Routes for New Energy Storage
3.1 System Efficiency
Lithium-ion battery storage, sodium-ion battery storage, flywheel energy storage, and superconducting energy storage have higher system efficiencies, ranging from 80% to 95%.
3.2 Cycle Life
Mechanical energy storage technologies such as gravitational energy storage, compressed air energy storage, and flywheel energy storage have significant advantages in cycle life, generally lasting 20 to 30 years.
3.3 kWh Cost
Compressed air energy storage has the lowest kWh cost among various new energy storage technologies, with a minimum of approximately 0.2 ¥/kWh. Lithium-ion battery storage and lead-carbon battery storage have comparable kWh costs and strong competitive advantages.
3.4 Technological Maturity
Technologies such as lithium-ion batteries, lead-carbon batteries, and molten salt sensible heat storage are in the commercial development stage. Lithium iron phosphate batteries are currently the most dominant technology route in new energy storage applications due to their high energy density, long cycle life, high efficiency, and fast response speed.
4. Future Development Trends of New Energy Storage
With the continuous expansion of renewable energy integration and the increasing demand for power system regulation capabilities, new energy storage is expected to usher in a period of rapid growth. The future development trends of new energy storage can be summarized as follows:
Diversified and Hierarchical Collaborative Development:
New energy storage technologies will exhibit a trend of diversified and hierarchical collaborative development. Various technical routes, including electrochemical energy storage, mechanical energy storage, electromagnetic energy storage, hydrogen storage, and thermal energy storage, will complement each other to meet the diverse needs of the energy system. Each technical route has its unique advantages and is applicable to different energy storage scenarios.
High Safety, Low Cost, Large Capacity, and High Efficiency:
The pursuit of high safety, low cost, large capacity, and high efficiency will remain the core objectives of new energy storage technology development. With technological advancements and scale effects, the cost of new energy storage will continue to decline, while its performance will be further enhanced. In particular, technologies such as lithium-ion batteries and vanadium redox flow batteries are expected to achieve significant breakthroughs in cost reduction and performance improvement.
Centralized, Digitalized, and Intelligent Development:
As the energy system becomes increasingly complex, the centralized, digitalized, and intelligent development of new energy storage will become an important trend. Through advanced information and communication technologies, new energy storage systems can be better integrated into the power grid, enabling more efficient energy management and utilization.
Green and Sustainable Development:
In line with global efforts to combat climate change, new energy storage will also pursue green and sustainable development. This includes the use of environmentally friendly materials, the reduction of energy consumption during the production and operation of energy storage systems, and the promotion of circular economy concepts.
Key Development Directions in the Near Future:
- Lithium-Ion Batteries: With high technological maturity, lithium-ion batteries will continue to dominate the new energy storage market. In particular, lithium iron phosphate batteries, with their high energy density, long cycle life, high efficiency, and fast response speed, will play a crucial role in the scale-up application of energy storage.
- Vanadium Redox Flow Batteries: Vanadium redox flow batteries, with their unique separation of capacity and power performance, long life, and high safety, are well-suited for large-scale and long-duration energy storage scenarios. As the industry chain continues to mature and scale effects emerge, their total life cycle cost is expected to be comparable to lithium-ion battery energy storage technology.
- Other Emerging Technologies: Technologies such as compressed air energy storage, flywheel energy storage, and superconducting energy storage also have significant potential. With ongoing research and development, these technologies are expected to achieve breakthroughs in performance and cost, further diversifying the new energy storage landscape.
In summary, new energy storage is poised for rapid growth, driven by the continuous expansion of renewable energy integration and the increasing demand for power system regulation capabilities. With diversified and hierarchical collaborative development, high safety, low cost, large capacity, high efficiency, centralized, digitalized, and intelligent development, as well as green and sustainable development as its core objectives, new energy storage will play a crucial role in the future energy system.