DEYE-STS500L

The Deye SUN-STS500L is a high-performance static transfer switch (STS) module specifically designed for commercial and industrial (C&I) energy storage systems. Its function is to provide fast, safe, and seamless switching between grid-connected, off-grid, and diesel generator modes, which is critical in facilities where uninterrupted power supply is a non-negotiable requirement from a business or technological standpoint. The SUN-STS500L is a key component of Deye’s modular ESS architecture and works closely with the PCS, MPPT, and battery units.
Fast and reliable switching for critical loads

One of the SUN-STS500L’s greatest advantages is its switching time of less than 20 ms, which makes the change in power source virtually imperceptible to connected loads. The module is capable of seamlessly switching between the utility grid, energy storage-backed island operation, and a diesel generator, making it an ideal solution for data centers, industrial production lines, logistics centers, or healthcare facilities. The load, grid, and generator branches are connected via independent, high-capacity paths, each capable of handling up to 500 kW of power.
High Power and System Integration

The Deye SUN-STS500L has a rated switching capacity of 500 kW and is specifically optimized for Deye C&I energy storage systems. A single STS module can serve five 100 kW PCS units or four 125 kW PCS units, allowing for flexible adaptation to various power levels. The module can be paralleled, and by using multiple STS units together, a system with a total capacity of up to 2.5 MW can be configured, providing significant scalability to meet growing energy demands.
Its role in Deye C&I energy storage systems

The Deye SUN-STS500L delivers the greatest value not as a standalone product, but as part of a complex energy storage ecosystem. It works closely with Deye PCS modules, MPPT units, and high-capacity battery systems, while its integrated EMS logic supports intelligent mode switching, load priority management, and maximized operational reliability.

The Deye SUN-STS500L is an industrial-grade, professional STS solution that is indispensable wherever uninterrupted power supply is a must. Due to its <20 ms switching time, 500 kW power rating, and tight integration with Deye PCS systems, we highly recommend it for C&I energy storage projects, particularly in applications involving critical loads, generator backup, and islanding. The SUN-STS500L provides a stable foundation for high-performance, future-proof energy management systems.