How much do you know about commercial and industrial energy storage?

What is industrial and commercial energy storage?

1. Industrial and commercial energy storage

"Industrial and commercial energy storage" refers to energy storage systems used in industrial or commercial terminals.

From the perspective of end customers, energy storage can be divided into power supply side, grid side, and user side energy storage, among which power supply side and grid side energy storage are also called pre-meter energy storage or large storage, while user side energy storage is called post-meter energy storage. User side energy storage can be further divided into industrial and commercial energy storage and household energy storage. In short, industrial and commercial energy storage is a type of user side energy storage, and its customer group is industrial or commercial terminals. Industrial and commercial energy storage has a wide range of application scenarios, including industrial parks, commercial centers, data centers, communication base stations, administrative buildings, hospitals, schools, residences, etc.

From the perspective of technical architecture, the industrial and commercial energy storage system architecture can be divided into two types: DC coupling system and AC coupling system. The DC coupling system usually adopts the form of a photovoltaic-storage integrated machine. The system consists of several major modules, including a photovoltaic-storage integrated machine (composed of a photovoltaic power generation system (mainly including photovoltaic power generation components and photovoltaic controllers, etc.), an energy storage power generation system (mainly including battery packs, bidirectional converters (Power Converting System, "PCS"), and a battery management system (Battery Management System, "BMS"), to achieve photovoltaic power generation + storage integration), and an energy management system (Energy Management System, "EMS system"). The basic operating principle is that the DC power generated by the photovoltaic power generation components directly charges the battery pack through the photovoltaic controller, and the AC power in the power grid can also be converted into DC power through the PCS and charged to the battery pack. When there is demand for electricity from the load, the battery will release current, and the energy collection point is at the battery end. The AC coupling system consists of several modules, including photovoltaic power generation system (mainly including photovoltaic power generation components and grid-connected inverters), energy storage power generation system (mainly including battery packs, PCS, BMS, etc.), and EMS system. The basic operating principle is: the DC power generated by the photovoltaic power generation components is converted into AC power through the grid-connected inverter, which can be directly fed into the power grid or supplied to the power load, or converted into DC power through PCS and charged to the battery pack. At this time, the energy collection point is at the AC end. The characteristics of the DC coupling system are low cost and low flexibility. It is suitable for scenarios where users use less electricity during the day and more electricity at night. The characteristics of the AC coupling system are high cost and high flexibility. It is suitable for application scenarios where photovoltaic power generation systems have been installed, as well as scenarios where users use more electricity during the day and less electricity at night. Generally speaking, the architecture of industrial and commercial energy storage systems can be separated from the large power grid and form a microgrid for photovoltaic power generation and battery storage.

2. Peak-valley arbitrage

“Peak-valley arbitrage” is a common profit model for industrial and commercial energy storage. That is, charging from the power grid when the electricity price is low and discharging when the electricity price is high.

Many countries implement different electricity price policies for time periods.

Take China as an example: General industrial and commercial electricity users only distinguish between peak and valley times. In summer (July, August, September) and winter (January, December), the electricity price during peak hours is 20% higher than the normal base price. During valley hours, the electricity price is 45% higher than the normal price. In other months, the electricity price during peak hours is 17% higher, and the electricity price during valley hours is 45% lower.

Therefore, industrial and commercial energy storage systems purchase low-priced electricity from the power grid when the electricity price is low. Supply loads during peak electricity prices, thereby reducing corporate electricity expenses.

3. Energy time shifting

"Energy time shifting" refers to the use of energy storage to achieve peak load shifting and valley load shifting. When the user uses power generation equipment such as photovoltaic cells to generate electricity, the power generation curve is not completely synchronized with the load consumption curve, so the user may sell the excess electricity to the power grid at a low price or purchase electricity from the power grid at a high price. Therefore, when the user uses the power generation equipment, the battery is charged. During the peak load period, the stored electricity is released to maximize economic benefits and reduce corporate carbon emissions.