User-side energy storage, as the name suggests, is an energy storage system installed on the electricity user's side, widely used in industrial and commercial parks, high-energy-consuming enterprises, and residential communities.
It, along with power-side energy storage and grid-side energy storage, constitutes the three major application areas of energy storage, but its **core characteristic** is that it directly serves the electricity needs of end users.
From a technical perspective, user-side energy storage systems typically consist of battery packs, a battery management system (BMS), a power conversion system (PCS), and an energy management system (EMS).
These systems are connected to the user's low-voltage busbar in the distribution room via 400V low voltage, relying on the EMS system to achieve intelligent control throughout the entire process.
User-side energy storage is transforming from a simple "power bank" to an "energy regulator" for cities. It not only stores electrical energy but also enables the spatial and temporal transfer of energy, optimizing resource allocation and improving energy utilization efficiency.
The most direct attraction of user-side energy storage lies in its economic value. It achieves peak shaving and valley filling by storing electricity during off-peak hours and discharging during peak hours.
For large industrial users, energy storage can also reduce peak loads and lower capacity electricity costs. User-side energy storage can also improve power supply reliability. By equipping it with power quality management equipment, harmonics can be filtered out in real time, reactive power can be compensated, and the risk of grid short circuits and overloads caused by equipment failures can be reduced.
In the event of a sudden grid failure, the system can switch to emergency power supply mode to ensure the continuous operation of critical equipment in the plant area. This function is particularly important for energy-intensive production enterprises, effectively preventing production interruptions and equipment damage caused by sudden power outages.
From a broader perspective, user-side energy storage provides a buffer for the integration of intermittent renewable energy sources such as photovoltaics, helping to improve the regional grid's capacity to absorb renewable energy.
So how does user-side energy storage generate profit?
Peak-valley price arbitrage is the core business model of user-side energy storage. The energy storage system charges during periods of low electricity prices and discharges during periods of high electricity prices, profiting from the price difference.
Since 2023, the peak-valley price difference has continued to widen in many parts of the country. In Zhejiang, the peak price difference reached 0.93 yuan/kWh, and in Shandong, Jiangsu, and other provinces, it exceeded the economic threshold of 0.7 yuan/kWh. This directly stimulated the demand for energy storage from industrial and commercial users.
For industrial enterprises using two-part tariffs, user-side energy storage can help reduce capacity charges by decreasing maximum demand.
Energy storage systems can discharge during peak grid load periods, reducing the power users draw from the grid and thus lowering capacity charges. This is particularly important for large industrial users whose electricity costs account for a high proportion (30%-50%) of their total electricity bills.
With the advancement of electricity market reforms, user-side energy storage can also generate additional revenue by participating in ancillary services such as demand response, frequency regulation, and reserve.
