Core Applications of Electrochemical Energy Storage in Power Systems
Introduction
nder the guidance of "dual carbon" goals, the global energy structure is accelerating its transition toward clean and low-carbon systems. Wind power and photovoltaic (PV) renewable energy have become the core drivers of energy growth. However, the inherent intermittency and volatility of renewable energy sources can lead to supply-demand imbalances on both the grid and load sides, causing grid frequency deviations and voltage fluctuations. These characteristics pose severe challenges to the safe and stable operation of power grids. As a critical link in energy conversion, energy storage technology has become essential infrastructure for addressing renewable energy integration bottlenecks and ensuring the safe and stable operation of new power systems.
01. Overview of Energy Storage Technology Routes
Current energy storage technologies exhibit diversified development: on one hand, pumped hydro storage remains an important traditional technology; on the other hand, new technologies such as electrochemical and compressed air energy storage are rapidly emerging. Based on energy storage methods, these technologies can be categorized into five types: mechanical, electrochemical, electromagnetic, thermal, and chemical. The key performance indicators of different energy storage technologies are compared as follows:
In summary, energy storage technology routes are diverse, each with its own strengths. Mechanical storage, with pumped hydro as the core technology, has cost advantages in large-capacity, long-duration regulation but is significantly constrained by geographical conditions. Electromagnetic storage occupies high-frequency regulation scenarios with millisecond-level response speed, but its low energy density and high cost make it difficult to achieve large-scale applications. Thermal and chemical storage focus more on energy form conversion in specific scenarios, with room for improvement in overall chain efficiency.
From a market share perspective, in addition to traditional pumped hydro storage, among new energy storage technologies, electrochemical storage accounts for 43.1%, with lithium-ion batteries dominating the electrochemical storage market at 97.5%, while other technologies such as flow batteries and lead-acid batteries account for less than 1%.
02. Current Status of Electrochemical Energy Storage Development
1. Market Growth Trend
In recent years, driven by both policy support and market demand, China's electrochemical energy storage market has experienced "explosive" growth. According to the "2024 Annual Electrochemical Energy Storage Power Station Industry Statistical Data" released by the China Electricity Council, from 2022 to 2024, China's electrochemical energy storage saw annual new installed capacity growth exceeding 100%. The cumulative installed capacity rapidly increased from 2.1 GWh in 2018 to 141.4 GWh in 2024, while new installed capacity grew from 1.4 GWh in 2018 to 90.5 GWh in 2024, demonstrating sustained leapfrog growth.
2. Technology Commercialization Process
Lithium-ion batteries offer advantages of high energy density, high efficiency, and long lifespan, making them the mainstream route for electrochemical energy storage. After years of technological iteration and industrial chain maturation, lithium battery-based electrochemical energy storage systems have achieved optimal balance among energy density, regulation precision, and cost control, enabling full-scenario applications from household storage to large-scale power stations. This dual advantage of "full-scenario compatibility + balanced performance" has established lithium-ion batteries as the dominant technology in current new energy storage systems.
Currently, lithium batteries have achieved large-scale commercial application, but costs are significantly affected by price fluctuations of upstream battery raw materials. As new technologies such as sodium-ion batteries achieve commercialization, electrochemical energy storage will further strengthen the foundation of new power systems, providing more robust support for clean and low-carbon energy transition.
03. Core Application Scenarios of Electrochemical Energy Storage
Electrochemical energy storage technology finds applications across industrial power consumption, electric vehicle charging, grid peak shaving and frequency regulation, and household self-consumption. In power systems, its applications have permeated the entire process of grid regulation and power supply assurance. By application scenario, it can be categorized into generation-side, grid-side, and user-side storage.
1. Generation-Side Applications
The core function is to smooth wind and solar power fluctuations, reduce wind and solar curtailment, and enhance renewable energy accommodation rates. This directly supports supply-demand balance between power generation and load sides, improving energy utilization efficiency.
2. Grid-Side Applications
Grid Peak Shaving: Through "charging during off-peak hours and discharging during peak hours," this application smooths power supply-demand fluctuations, effectively alleviating peak grid supply pressure. It has become a core tool for flexible grid peak shaving and valley filling. Currently, the peak shaving market is gradually integrating with electricity spot markets, further enhancing the market value of peak shaving services and resource allocation efficiency.
Grid Frequency Regulation: Rapidly correcting real-time differences between load and generation power, energy storage systems offer high regulation precision, effectively controlling grid frequency deviation ranges and enhancing grid frequency stability.
Improving Power Quality: For issues such as voltage sags and harmonic pollution, energy storage systems can stabilize voltage through instantaneous power compensation and suppress current harmonics. In precision manufacturing and data centers with high power quality requirements, this ensures continuous and stable equipment operation, reducing losses caused by power quality issues.
3. User-Side Applications
Electrochemical energy storage applications on the user side primarily focus on the industrial and commercial sectors, with application scenarios including peak-valley arbitrage, emergency power supply assurance, renewable energy accommodation, demand-side response, and demand management. The characteristics of these scenarios are as follows:
The economics of user-side energy storage is a core driver of its rapid development, particularly evident in the industrial and commercial sector. Taking a 10kV general industrial and commercial energy storage project (single-tariff settlement method) in Zhejiang as an example: with a peak-valley electricity price difference of approximately 0.7557 yuan/kWh, a configuration of 10 units of 100kW/200kWh energy storage cabinets (total capacity 2MWh, total investment 1.5 million yuan, 5-year depreciation period, 90,000 yuan/MWh annual operation and maintenance budget), operating in a "two-charge two-discharge" mode (charging during nighttime and midday valleys, discharging during peak self-consumption periods), with stable annual operation of 330 days and 88% charge-discharge efficiency, the revenue calculation is as follows:
The project discharges approximately 3,520 kWh per day, generating daily revenue of about 2,504 yuan and annual revenue of 827,000 yuan. After deducting annual equipment depreciation of 300,000 yuan and annual O&M costs of 180,000 yuan, the annual net profit reaches 347,000 yuan, achieving cost recovery within 4.4 years.
This case clearly demonstrates that user-side energy storage can effectively reduce corporate peak-period electricity purchase costs through peak-valley price arbitrage, offering good investment value and sustainable operational capability, with significant economic advantages.
4. Other Applications
With fast response and stable supply characteristics, electrochemical energy storage also finds extensive applications in other fields such as backup power sources, black start capabilities, and microgrid operation support.
Conclusion
Currently, lithium battery energy storage technology is mature and has achieved commercial applications across generation-side, grid-side, and user-side scenarios, driving "explosive" growth in China's electrochemical energy storage installed capacity.
Behind this rapid development, the industry still faces three core challenges: first, cost constraints, with significant price fluctuations in lithium battery upstream raw materials - battery costs have decreased to less than half of 2018 levels, but cost control remains challenging; second, efficiency bottlenecks, with room for optimization in collaborative control technologies between energy storage systems, grids, and renewable energy sources; third, safety concerns, with the industry lacking unified safety standards and facing non-negligible thermal runaway and fire risks in large-scale energy storage power stations.
In the future, with policy improvements, technological iterations, and cost reductions, electrochemical energy storage systems will be more deeply integrated into power systems. Technologies such as sodium batteries and flow batteries will also accelerate maturity and achieve commercial applications, promoting energy transition. These technologies will complement lithium batteries, further reducing energy storage costs and providing core technical support for high-penetration renewable energy integration and the realization of "dual carbon" goals.