01 Industrial and commercial energy storage overview
“Industrial and Commercial energy storage” means energy storage systems used in industrial or commercial terminals.
From the perspective of end customers, energy storage can be divided into power side, power grid side, and user side energy storage, of which power side and grid side energy storage is also called pre-table energy storage or large storage, and user side energy storage is called post-table energy storage. User-side energy storage can be further divided into industrial and commercial energy storage and home energy storage. In short, industrial and commercial energy storage is a kind of user-side energy storage, and its customer group is industrial or commercial terminals.
Industrial and commercial energy storage application scenarios are wide, including industrial parks, commercial centers, data centers, communication base stations, administrative buildings, hospitals, schools, residential and so on.
Industrial and commercial energy storage system is different from large-scale energy storage peak-modulation power stations, its main purpose is to use the grid peak-valley difference to achieve return on investment, the main load is to meet the industrial and commercial internal power demand, to maximize photovoltaic power generation for self-use, or through the peak-valley spread arbitrage.
Industrial and commercial energy storage systems and energy storage power station systems include battery systems +BMS, PCS, EMS, transformers, racks, connection cables, bus cabinets, lightning protection and grounding systems, monitoring and alarm systems, etc., the system is modular design, system voltage, capacity flexible configuration.
There are two main types of commercial energy storage system architectures:
1) The AC coupling type of PCS: the AC coupling system is similar to the system configuration of the energy storage power station, but the relative amount is small, and the system function is simpler, wherein the photovoltaic system and the energy storage system are parallel, and the flexibility is higher, which is suitable for the installed industrial and commercial photovoltaic stock market.
2) DC coupling type of optical storage machine: DC coupling system integrates photovoltaic inverter and bidirectional converter through optical storage machine, compared with AC coupling system with highly integrated, soft and low cost characteristics, 50-100kW optical storage machine has gradually become the choice of small and medium-sized industrial and commercial energy storage system.
Industrial and commercial energy storage application scenarios are broad and scattered, and the current industrial and commercial energy storage application scenarios mainly include the following four categories:
- Separate configuration of energy storage: There are two main considerations for industrial and commercial users to configure energy storage separately: First, to save electricity costs for enterprises by cutting peaks and filling valleys. For example, the peak price of 1 yuan per degree, and the trough price of 0.3 yuan per degree, industrial and commercial users can charge the energy storage at the trough, and then use the energy storage for power supply during the peak period, then the cost of electricity for the enterprise in the peak period is 0.3 yuan per degree, rather than the original 1 yuan per degree, saving 0.7 yuan per degree of electricity costs. Second, use energy storage as a backup power supply for emergencies.
- Integration of optical storage and charging: Integration of optical storage and charging refers to the integration of photovoltaic power generation, energy storage and charging piles to achieve efficient use of energy and convenient charging. The application of energy storage makes it possible for user side self-use, improves the self-use rate of distributed photovoltaic, and can also alleviate the impact of charging piles on regional power grids with large current charging.
3, microgrid + energy storage: Microgrid is a localized small power distribution system with its own power generation capacity. Usually, it is based on distributed power supply, and uses energy storage and control devices for real-time adjustment to achieve power balance within the network. It can operate independently of the main network, and can also work with the main network. For microgrids operating independently of the main network, energy storage can smooth new energy generation and be used as backup power supply, and for grid-connected microgrids, energy storage can achieve energy optimization and energy saving and emission reduction. - New application scenarios: Industrial and commercial energy storage actively explores new scenarios for integration and development, which have appeared in many application scenarios such as data centers, 5G base stations, power replacement heavy trucks, and port power.