Transforming the Energy Storage Landscape: String PCS and Active Balancing Technologies

The energy storage sector in the United States achieved a significant milestone in 2024, with the California Independent System Operator (CAISO) exceeding 13 gigawatts (GW) of grid-scale storage capacity. Concurrently, regions such as the Electric Reliability Council of Texas (ERCOT) are witnessing rapid growth, while opportunities for deployment are emerging in the Midwest and Southeast. This transformation is largely driven by increasing demands for clean power, which are anticipated to nearly double in ERCOT by 2030 due to population expansion and extreme weather conditions. In this context, energy storage solutions have become essential for ensuring grid stability and meeting the growing energy needs of diverse sectors.

At the Energy Storage Summit USA held in Dallas from March 26-27, 2025, CLOU North America’s General Manager, Steven Chan, presented the pivotal role of battery storage in addressing Texas's projected surge in peak energy demand. The summit gathered nearly 1,000 professionals from the industry, including CLOU's Overseas GM, Songyu He, and a team of experts who collectively discussed the need for innovation in energy storage.

Chan emphasized that success in energy storage cannot merely be established through advanced technology; it necessitates strong financial backing, optimized operations, and a steadfast commitment to growing in tandem with shifting grid requirements and investor expectations. Two cutting-edge technologies discussed at the summit were String PCS and Active Balancing, which promise to significantly enhance the performance and efficiency of energy storage systems.

Traditional storage systems, which typically utilize passive balancing methodologies, often suffer from voltage imbalances within battery packs. Such imbalances lead to increased maintenance requirements and prolonged downtimes, costing engineers time and resources—between roughly $192,000 and $3.84 million over a 20-year period. CLOU's Active Balancing technology provides a solution by meticulously maintaining cell voltage deviations to under 5 millivolts, thereby bolstering performance while minimizing balancing time. This innovative approach not only leads to a 4% increase in capacity but also extends the lifespan of battery systems by approximately 2.13%, while reducing both maintenance costs and system downtime.

CLOU's TX10 project in Texas set a precedent in the industry by implementing a full-scale cell-to-rack active balancing system. This project yielded remarkable outcomes, with all nine participating sites ranking among ERCOT's top 30 in terms of market revenue in 2023, generating an impressive $196,000 per megawatt annually, as reported by Modo Energy.

In addition to Active Balancing, Chan outlined the benefits of using String PCS over traditional Centralized PCS systems. In instances where a centralized PCS fails in a 5 megawatt-hour (MWh) system, the entire system faces total outage. Conversely, a failure in a String PCS affects only the impacted unit, roughly accounting for 0.417 MWh, which amounts to just 1/12th of the total system capacity. This redundancy can improve system availability by 4.8% in a 100 MWh project, significantly enhancing reliability.

CLOU Electronics, a subsidiary of Midea Industrial Tech, is actively broadening its reach on a global scale. Songyu He underlined the company’s flexible solutions that stem from software and system integration partnerships. By harnessing the latest advancements in technology and proactively addressing future energy storage challenges, CLOU is poised to lead the next wave of innovation in the sector.

As the energy storage sector continues to evolve, it is evident that technologies like String PCS and Active Balancing are not just enhancements; they are transformative solutions essential for meeting the energy demands of the future. With ongoing advancements and strategic initiatives, CLOU Electronics is steadfast in its mission to redefine energy storage and contribute meaningfully to a sustainable energy framework across regions.