CESC showcased its Mercury 418 series C&I ESS at the event
This is integrated with an external 215 kW PCS with 2 different AC-side voltage levels of 690 V and 800 V, providing choices to match the existing PV inverter’s AC voltage level
The 215 kW/418 kWh ESS platform can be expanded to a 215 kW/8.36 MWh system by connecting 20 units in parallel
With the growing push towards energy security and independence due to geopolitical uncertainty and negative grid tariffs, European commercial & industrial (C&I) consumers with existing PV capacity are installing cabinet-based C&I energy storage systems (ESS) to store excess energy. These systems are charged by the grid or discharged to connected loads via a power conversion system (PCS) at varied voltage (AC) levels. However, when AC-coupling the existing PV inverters with the ESS, the AC output voltage of the PCS and PV inverter often don’t match. This leads to connecting an additional transformer between the PCS and the common AC busbar to match the PV inverter’s rated voltage. As a result, the CapEx and installation and commissioning time for the ESS escalate.
CESC Power, a Germany-based ESS provider, promoted its C&I ESS, Mercury 418, to address these challenges. Measuring 1,400 × 1,680 × 2,335 mm (W × D × H), it is equipped with lithium-iron-phosphate cell-based battery stacks with 418 kWh of cumulative storage capacity. The cabinet also features an energy management system (EMS) and battery management system. Its storage capacity is coupled with the C&I consumer point of connection (AC-side) via an external 215 kW PCS at 690 or 800 V 3-phase AC voltage. According to the company, this voltage flexibility helps match the rated voltage of existing PV inverters and facilitates direct connection with the ESS without an additional transformer. Therefore, it saves transformer costs and simplifies on-site grid connections of the ESS. This 215 kW/418 kWh ESS can be expanded to a 215 kW/8.36 MWh system by connecting 20 units in parallel, matching C&I consumers’ growing demands.
Its operational thermal management is based on a liquid coolant, which circulates 24/7 across the battery surface and absorbs heat to maintain cell-to-cell temperature variance within 5°C. These cells have a guaranteed life of at least 8,000 cycles.
In terms of operations, this ESS’s integrated EMS, with its embedded algorithms, provides real-time monitoring and predictive control for discharge during the exact time span that coincides with scheduled load overshooting and high tariff rates. In addition to peak shaving, these algorithms help to find the sweet spot of dynamic tariffs in the energy trading market and participate in energy arbitrage. The company says the product is suitable for applications in large C&I parks, data centers, charging parks & public charging stations, and commercial centers & logistics.
