Analysis of Core Operational Performance Indicators of Energy Storage Power Stations
The issuance of Document No. 136 signals the withdrawal of the “strong配” model, indicating a shift of energy storage projects from a policy-driven approach to a market-driven development model. Energy storage projects will face genuine market-oriented tests moving forward. Once fully integrated into the electricity market, energy storage power stations will generate revenue by participating in various services, whether in the electricity spot market, auxiliary service market, or through the low storage, high discharge operating mode of commercial and industrial storage. In this competitive landscape, energy storage power stations will follow the principle of “survival of the fittest.”
In the early stages of market development, the quality of energy storage devices varied significantly. Some manufacturers prioritized marketing over research and development, resulting in projects that focused heavily on construction rather than operational efficiency. This has led to low overall utilization rates and highlighted numerous issues, with actual operational conditions often overlooked. In the future, the operational capability of energy storage projects will be the most critical measure of a power station’s level. The profitability of each project will become differentiated, with significant revenue discrepancies even among energy storage power stations of the same type and in the same region due to variations in operational performance.
Measuring the operational performance indicators of energy storage power stations is crucial, primarily reflected in four main aspects:
- Grid-Connected Performance: For energy storage power stations under grid dispatch control, which includes both source-side and grid-side storage, their grid connection performance must meet the safety and stability requirements of the power system. In practical projects, after connecting to the grid, energy storage power stations are required to engage third-party testing agencies to conduct grid connection tests. These tests evaluate power control, primary frequency regulation, inertia response, fault ride-through, operational adaptability, power quality, and automated scheduling to ensure compliance with relevant technical requirements. Failure to meet grid connection performance indicators can adversely affect commercial operations and lead to assessments under the “two detailed rules.” For instance, a primary frequency regulation function should have a dead zone set at ±(0.03~0.05) Hz, a regulation rate of 0.5~3%, and a regulation response time not exceeding 4 seconds.
- Charge and Discharge Efficiency: Charge and discharge efficiency is a key indicator for evaluating the performance of energy storage power stations. This efficiency is defined as the ratio of the discharge energy at the grid connection point to the charging energy during the evaluation period, reflecting the effectiveness of energy conversion. It is closely related to equipment selection, engineering design, operational modes, and auxiliary power consumption. Enhancing the charge and discharge efficiency of energy storage power stations can reduce energy losses and improve their support and regulation capabilities for the grid, thereby maximizing revenue. For example, newly operational shared energy storage projects have a single charge and discharge efficiency of around 82% to 89%, with an annual efficiency between 76% and 86%. Additionally, as the lifespan of storage batteries increases, efficiency may decline by 1% to 2%. Different projects exhibit significant variations in charge and discharge efficiency, which can be improved through the selection of energy-efficient transformers, low-loss storage converters, enhanced battery temperature control designs, and reasonable thermal management device operating strategies.
- Availability Rate: Availability rate reflects the operational reliability of energy storage equipment. It is calculated as the sum of charge and discharge time and hot standby time divided by the total time during the evaluation period. Due to varying quality levels of storage equipment from different manufacturers, availability rates can differ significantly across projects. For instance, some lithium battery storage projects can achieve nearly “maintenance-free” operation with high stability, while others frequently encounter various equipment failures, such as communication issues in storage units, frequent alarms for battery voltage during charge and discharge, overheating of IGBT modules, and leakage in liquid cooling pipelines. Such issues necessitate frequent shutdowns for repairs, increasing operational costs and reducing the availability of the energy storage power station.
- Charge and Discharge Capacity: The charge and discharge capacity of energy storage power stations is influenced not only by efficiency but also closely relates to the State of Health (SOH) of the storage batteries. As batteries age during use, their charge and discharge performance undergoes permanent degradation, leading to a gradual decline in charge and discharge capacity. SOH is closely tied to the charge and discharge ratio of the storage system and the depth of discharge, as well as factors such as battery type, operating temperature, and the topology of storage units. For example, various battery manufacturers claim to achieve 8,000, 10,000, or even 15,000 cycles, but in actual project operations, the actual cycle life can differ significantly even under the same evaluation standards (e.g., 25°C, 80% SOH). Some manufacturers do not meet their claimed lifespans, and for projects that were launched earlier, batteries may retire from service within three years, significantly falling short of the expected total lifespan and charge and discharge capacity.
CIES 2025 Energy Storage Conference: The CIES 2025 Energy Storage Conference is jointly hosted by the Energy Storage Application Branch of the China Chemical and Physical Power Industry Association, the China Energy Storage Network, and the Digital Energy Storage Network, with academic support from the Expert Committee of the Energy Storage Application Branch. The conference will feature sessions including the opening ceremony and invited expert reports, innovation in smart distribution networks and new energy storage integration, new power systems and grid dispatching, the collaborative development of new energy storage and large renewable energy bases, international energy storage and power auxiliary services, spot trading and capacity markets, industrial green microgrids, national energy storage standards promotion, smart new energy storage system integration solutions, energy storage fire safety, security and certification, new energy storage capital and investment, flow batteries, compressed air storage and long-duration energy storage technologies, hybrid energy storage, global opportunities and challenges in new energy storage supply chains, smart commercial energy storage solutions and case studies, virtual power plants and vehicle-grid interaction, construction of grid-connected energy storage systems and projects, ESG for dedicated energy storage batteries, and new product launches, totaling 23 sessions.
During the conference, a series of research achievements will be released, including the “2025 White Paper on the Development of China’s New Energy Storage Industry,” the “2025 White Paper on the Development of Industrial Green Microgrids,” and the “2025 Analysis Report on Bidding and Pricing for New Energy Storage Industry Projects.” It is expected that over 60,000 guests and more than 1,000 enterprises will participate in discussions and exchanges, including representatives from government agencies, research institutions, grid companies, power generation groups, EPC contractors, system integrators, energy storage device manufacturers, energy service providers, project developers, investment and financing institutions, and international buyers. Since its inception in 2011, the China International Energy Storage Conference and Exhibition (CIES) has been committed to high-end, quality, and international features, promoting cooperation in domestic and international supply chains and channels exceeding 500 billion yuan and assisting local governments in attracting investment and project cooperation exceeding 100 billion yuan, thereby facilitating various capital collaborations totaling 300 billion yuan.
This year’s exhibition will feature a “4+1+1” layout, including areas for energy storage system integration, power generation groups, electrical equipment, temperature control devices, control systems, energy storage batteries, testing and certification, fire safety, and other product displays. The exhibition will focus on cutting-edge technologies and practices in the energy storage field, actively building communication channels between government and enterprises, exploring new paths for high-quality development in the energy storage industry, promoting in-depth connections among high-end innovative elements such as specialized technologies, capital, and services, and showcasing new products, technologies, equipment, and services from both domestic and international markets. This aims to help exhibitors expand brand influence and recognition, actively develop domestic and international market channels, enhance the competitiveness and market share of self-controlled products, and accelerate the core value growth of Chinese energy storage brand enterprises, contributing “energy storage wisdom” and “energy storage solutions” to the construction of a green, efficient, flexible, intelligent, and sustainable modern energy system.
We welcome you to participate in the 15th China International Energy Storage Conference and Exhibition in 2025.
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