Sunlight Power Revolutionizes Energy Storage Management with BM²T Technology to Overcome Key Challenges

Addressing the Four Major Shortcomings in Energy Storage Management: Sungrow’s BM²T Initiates a System-Level Intelligent Revolution

Safety and economic viability have always been the two key levers driving the development of the energy storage industry. Following the release of Document No. 136, the energy storage sector is expected to face an increasingly fierce elimination competition, where these two characteristics will be critical for the survival and growth of companies. As energy storage transitions towards digital and intelligent transformation, how can we enhance safety and economic effectiveness?

At the Beijing Energy Storage Exhibition on April 10, an in-depth analysis of Sungrow’s BM²T Battery Management Technology White Paper revealed that this leading company has officially initiated a “value” transformation and has made a “key” move: battery data will unlock marketization and enhance its value. The white paper indicates that Sungrow’s products are designed based on the integration of three electrical systems, along with real-time monitoring and dynamic management mechanisms. This approach enables system-level management of batteries, thereby enhancing overall safety and efficiency in energy storage systems and promoting a comprehensive upgrade towards digital intelligence in the sector.

In interpreting the white paper, it is clear that Sungrow has moved beyond the traditional battery management system (BMS) framework, creating an ecosystem for energy storage that spans from battery to grid. This system aims to achieve “value enhancement” throughout the entire lifecycle of energy storage, including aspects like power trading and auxiliary services, which genuinely align with grid demands. So, why emphasize battery data at this stage? How is “value enhancement” achieved?

Battery ≠ Energy Storage System: Addressing the Inefficient Applications of Batteries

In 2024, the Electric Power Research Institute (EPRI) released a report revealing that 46% of anomalies in battery storage systems are caused by control issues, including battery management. Many fire safety incidents are directly linked to thermal runaway in batteries, making battery management crucial for energy storage. Particularly for energy storage operations, battery lifespan is vital to overall profitability.

According to Zhou Jianjie, Chief Technical Expert of Sungrow’s Energy Storage Division, current battery management practices often operate in isolation rather than as a system-wide approach. Most solutions focus on external symptoms, applying a “treat the pain” method that only temporarily resolves issues without addressing the root causes. The ideal goal for energy storage applications is for batteries to achieve their full lifespan and “naturally fail,” necessitating consideration of battery conditions and usage scenarios. Four key management misconceptions stand out:

• Inadequate Comprehensive Monitoring of Battery Data: Single data points fail to provide a complete picture of cell conditions, leading to delayed thermal runaway alerts. Most companies focus solely on monitoring cell temperature, yet excessive investment in temperature sensors does not enhance overall storage safety.
• Immature Battery State Estimation Techniques: This results in inaccurate estimations of state of charge (SOC) and state of health (SOH). If accurate thresholds cannot be identified and boundaries are set blindly, it may mask suboptimal battery states, posing safety risks.
• Isolation Effects in Data: Particularly when components from different manufacturers are integrated, inconsistent interfaces and communication protocols hinder effective data transmission, exacerbating isolation issues.
• Inaccurate Fault Localization: Due to one-size-fits-all alert thresholds and misconfigurations, a single fault may trigger multiple parallel issues, increasing customer anxiety and complicating fault analysis.

From the challenges of accurately estimating cell conditions to frequent fault alerts and ineffective data extraction, relying solely on BMS will not resolve these issues. Sungrow emphasizes that energy storage systems should prioritize energy dispatch needs from the grid, facilitating effective utilization of batteries across all levels of the system.

This is why Sungrow has taken the initiative to release the BM²T Battery Management Technology white paper. BM²T refers to a comprehensive battery management technology that employs real-time monitoring and dynamic management mechanisms to achieve a full-loop management process from signal acquisition to state assessment and proactive control, ultimately ensuring the safety, efficiency, and longevity of energy storage systems.

To realize such functionality, companies must possess a deep understanding of full-stack technologies for energy storage systems and have substantial technical capability and experience, supported by cutting-edge technologies like artificial intelligence, big data, and the Internet of Things. Sungrow has successfully integrated and utilized various technologies.

Integrating Intelligent and System-Level Technologies to Address the Four Major Shortcomings of Inefficient Management

While battery management remains a focal point, Sungrow, as an energy storage system integrator, has a broader perspective on technological innovation compared to typical cell manufacturers or third-party BMS providers focused on isolated technological upgrades. Zhou Jianjie notes, “We aim to maximize the value of every watt produced by each cell within a smart system.” Achieving this requires a comprehensive evolution of technical, value, and ecological perspectives.

In response to the identified four major shortcomings in battery energy management, Sungrow has proposed strategies that include in-depth research on vertical management from the grid to the system and from the system to the battery. This encompasses multi-dimensional management of battery electrical, thermal, and mechanical characteristics, alongside constructing a full lifecycle model for batteries. They aim to strengthen an innovative three-layer architecture that enhances battery signal perception, state awareness, and controllability.

However, realizing this management architecture is highly challenging. Zhou Jianjie emphasizes the need to comprehend the “life cycle” of batteries from a system scheduling perspective. Sungrow has consistently ranked among the top in global energy storage system installations, possessing the richest datasets from destructive testing of multiple battery brands and project application data across various power systems.

With models trained on this extensive data, the company can effectively manage batteries and trading under various conditions. From the information perspective, energy storage systems require high precision, multi-dimensional, and low-latency information to ensure perceivable data. “Sensing provides certainty for equipment, but this certainty requires expert experience for identification,” Zhou explains.

Sungrow is committed to addressing electrochemical uncertainties through deterministic technologies that enable multi-dimensional precise identification. By adopting integrated sampling technologies and incorporating temperature compensation and common-mode interference suppression, they achieve high-precision detection across full temperature ranges and lifecycle conditions.

As battery monitoring poses significant challenges, especially during thermal runaway events where lithium iron phosphate battery systems may not exhibit clear characteristics, Sungrow has successfully overcome these hurdles. By leveraging the “dual-peak breathing effect” of battery cells and the regular changes in cell expansion characteristics, they have developed SOC/SOH estimation algorithms that precisely assess battery states.

To ensure the usability of this information, Sungrow has implemented a unified internal communication system within energy storage systems, replacing traditional hierarchical architectures. This significantly enhances response speed to safety faults and bolsters the ability to support large-scale network construction.

Moreover, ensuring the effectiveness of information is crucial. Zhou states, “Many warnings in the industry are ‘ineffective’ during actual use. We need to inform customers of necessary actions at the right moment, which highlights the value of perception technology.” While many in the industry promote the capacity to provide alerts two hours, 24 hours, or even seven days in advance, merely extending the lead time for alerts is not practically valuable; improving accuracy is paramount.

The battery operation state big data platform jointly developed by Sungrow and Tsinghua University aims to leverage this value. By establishing multi-dimensional coupling and multi-physical field mechanism models, the company has comprehensively defined core battery states such as BOL, SOL, EOL, and RUL, allowing for more efficient alignment with control strategies.

Ultimately, by achieving signal perception and state awareness and aggregating diverse data, the goal is to realize controllable systems. “The integration of AC and DC control is the final point of the white paper. We seek to reflect electrical characteristics from the AC side on the DC side and create integrated management based on three major technologies.” This intelligent control aims to enhance the safety and economic viability of energy storage systems.

According to Sungrow, leveraging existing technologies alongside extensive data utilization can aid AI thermal management technologies to decrease product power consumption by 34%, control SOH errors within 2%, increase annual discharge volume by 7.3GWh for a 1GWh energy storage station under daily charge and discharge modes, and achieve thermal runaway warnings with an accuracy of ≥99%, facilitating system disconnection and enhancing safety. This illustrates the value of precise management technology for energy storage project operators and investors.

In the early stages of energy storage industry development, companies aiming to lead require forward-looking strategic vision. However, maintaining a leading position in the long-term development of energy storage demands comprehensive strength. Sungrow has continuously been at the forefront of the energy storage industry in terms of technology and product development, and beyond products, it also plays a significant guiding role in the industry. In recent years, based on the concept of “three electrical integrations” involving electrochemical storage, power electronics, and the grid, and leveraging its deep understanding of lithium battery storage, Sungrow has accurately identified industry pain points and issued targeted solutions through white papers on various technologies, filling numerous technical gaps in the sector. Facing the profound changes ahead in the energy storage industry, Sungrow believes that safety remains a core concern. It is essential for companies to establish a solid foundation and continuously create value through technological innovation, providing higher quality products and deeper management services to meet the elevated technical requirements of power market transactions from the DC to AC sides.