What is a stacked energy storage system? Stacked energy storage systems utilize modular design and are divided into two specifications: parallel and series. They increase the voltage and capacity of the system by connecting battery modules in series and parallel, and expand the capacity by parallel connecting multiple cabinets. Mainstream inverters are compatible with and can be matched with energy storage products, enabling plug-and-play functionality. The fully modular design allows for easy addition or subtraction of module quantity, convenient maintenance and expansion, quick display of product status, and automated intelligent management without the need for manual operation.
Stacked energy storage systems: Low-voltage stacking vs. high-voltage stacking
In stacked energy storage systems, they are generally divided into low-voltage stacking and high-voltage stacking. Although both are stacked energy storage, what are the differences? Let’s analyze them from the following points:
- Different voltage levels: Low-voltage stacking generally refers to voltages below48V (51.2V), which means a module consisting of 16 batteries connected in series; high-voltage stacking is generally between 48V-800V.
- Different design complexity: In high-voltage stacking schemes, a bidirectional DC-DC converter for battery charging is required to increase the battery output voltage to the input voltage of the AC inverter, which increases the design complexity and cost. In low-voltage stacking schemes, the battery output voltage is similar to the inverter input voltage, eliminating the need for a converter, resulting in a relatively simpler design and lower cost.
- Different module connection methods: In high-voltage stacking schemes, modules are connected in series, increasing the voltage while maintaining the same battery capacity; in low-voltage stacking schemes, modules are connected in parallel, increasing the capacity while keeping the voltage constant.
- Different safety levels: In high-voltage stacking schemes, higher voltage batteries are used, requiring higher safety requirements for the system. In low-voltage stacking schemes, lower voltage batteries are used, resulting in relatively lower safety requirements for the system.
- Different scalability: In high-voltage stacking schemes, the minimum unit is generally 3 or 4 modules connected in series; in low-voltage stacking schemes, the minimum unit is 1 module.
- Different energy conversion: In low-voltage stacking schemes, there is energy loss during the transmission of current, while high-voltage systems can reduce energy loss by reducing current values. For example, with the same 10 degrees of electricity, the high-voltage scheme can actually obtain 2 more degrees of electricity than the low-voltage scheme.
Additionally, high-voltage systems can charge and discharge more efficiently, tolerate higher energy density, and are suitable for storing large amounts of energy. Low-voltage systems are more suitable for small-scale energy storage systems, such as home energy storage systems, etc.
In conclusion, the choice between high-voltage and low-voltage systems depends on the application requirements and the amount of energy to be stored in the energy storage system.