Photovoltaics plus energy storage have many benefits. First, it ensures a more stable and reliable power supply. The power storage device is like a large battery that stores excess solar energy. When the sun is insufficient or the demand for electricity is high, it can provide power to ensure continuous power supply.
Secondly, photovoltaics plus energy storage system can also make solar power generation more economical. By optimizing operation, it can allow more electricity to be used by itself and reduce the cost of purchasing electricity. Moreover, power storage equipment can also participate in the power auxiliary service market to bring additional benefits. The application of power storage technology makes solar power generation more flexible and can meet various power needs. At the same time, it can also work with virtual power plants to achieve the complementarity of multiple energy sources and the coordination of supply and demand.
Photovoltaic energy storage is different from pure grid-connected power generation. Energy storage batteries and battery charging and discharging devices need to be added. Although the upfront cost will increase to a certain extent, the application range is much wider. Below we introduce the following four photovoltaic + energy storage application scenarios based on different applications: photovoltaic off-grid energy storage application scenarios, photovoltaic off-grid energy storage application scenarios, photovoltaic grid-connected energy storage application scenarios and microgrid energy storage system applications. Scenes.
1. Photovoltaic off-grid energy storage application scenarios
Photovoltaic off-grid energy storage power generation systems can operate independently without relying on the power grid. They are often used in remote mountainous areas, powerless areas, islands, communication base stations, street lights and other application places. The system consists of a photovoltaic array, a photovoltaic inverse control integrated machine, a battery pack, and an electrical load. The photovoltaic array converts solar energy into electrical energy when there is light, supplies power to the load through the inverter control machine, and charges the battery pack at the same time; when there is no light, the battery supplies power to the AC load through the inverter.
Photovoltaic off-grid power generation systems are specially designed for use in areas without power grids or areas with frequent power outages, such as islands, ships, etc. Off-grid systems do not rely on large power grids, but rely on "storage and use" or "storage first and use later" The working mode is to provide help in times of need. Off-grid systems are highly practical for households in areas without power grids or areas with frequent power outages.
2. Photovoltaic and off-grid energy storage application scenarios
Photovoltaic off-grid energy storage systems are widely used in applications such as frequent power outages, or photovoltaic self-consumption that cannot be connected to the Internet, high self-consumption electricity prices, and peak electricity prices are much more expensive than trough electricity prices.
The system consists of a photovoltaic array composed of solar cell components, a solar and off-grid all-in-one machine, a battery pack, and a load. The photovoltaic array converts solar energy into electrical energy when there is light, and supplies power to the load through the solar control inverter all-in-one machine, while charging the battery pack; when there is no light, the battery supplies power to the solar control inverter all-in-one machine, and then AC load power supply.
Compared with the grid-connected power generation system, the off-grid system adds a charge and discharge controller and a battery. The system cost increases by about 30%-50%, but the application range is wider. First, it can be set to output at rated power when the electricity price peaks, reducing electricity expenses; second, it can be charged during valley periods and discharged during peak periods, using the peak-valley price difference to make money; third, when the power grid fails, the photovoltaic system continues to work as a backup power supply. , the inverter can be switched to off-grid working mode, and photovoltaics and batteries can supply power to the load through the inverter. This scenario is currently widely used in overseas developed countries.
3. Photovoltaic grid-connected energy storage application scenarios
Grid-connected energy storage photovoltaic power generation systems generally operate in an AC coupling mode of photovoltaic + energy storage. The system can store excess power generation and increase the proportion of self-consumption. Photovoltaic can be used in ground photovoltaic distribution and storage, industrial and commercial photovoltaic energy storage and other scenarios. The system consists of a photovoltaic array composed of solar cell components, a grid-connected inverter, a battery pack, a charge and discharge controller PCS, and an electrical load. When the solar power is less than the load power, the system is powered by solar energy and the grid together. When the solar power is greater than the load power, part of the solar energy supplies power to the load, and part is stored through the controller. At the same time, the energy storage system can also be used for peak-valley arbitrage, demand management and other scenarios to increase the system's profit model.
4. Microgrid energy storage system application scenarios
As an important energy storage device, microgrid energy storage system plays an increasingly important role in my country's new energy development and power system. With the advancement of science and technology and the popularization of renewable energy, the application scenarios of microgrid energy storage systems continue to expand, mainly including the following two aspects:
A. Distributed power generation and energy storage system: Distributed power generation refers to the establishment of small power generation equipment near the user side, such as solar photovoltaic, wind energy, etc., and the excess power generation is stored through the energy storage system so that it can be used during peak power periods or Provides power during grid failures.
B. Microgrid backup power supply: In remote areas, islands and other places where power grid access is difficult, the microgrid energy storage system can be used as a backup power supply to provide stable power supply to the local area.
Microgrids can fully and effectively utilize the potential of distributed clean energy through multi-energy complementation, reduce unfavorable factors such as small capacity, unstable power generation, and low reliability of independent power supply, ensure the safe operation of the power grid, and are a useful supplement to large power grids. Microgrid application scenarios are more flexible, the scale can range from thousands of watts to tens of megawatts, and the application range is wider.
