Photovoltaic power generation grid connection policy

Photovoltaic power generation systems can be divided into off-grid photovoltaic power generation systems and grid-connected photovoltaic power generation systems. Grid-connected photovoltaic power generation systems require 25% less investment than off-grid photovoltaic power generation systems. Connecting the photovoltaic power generation system to the large power grid in the form of a microgrid and supporting each other with the large power grid is an important technical way out to increase the scale of photovoltaic power generation. The grid-connected operation of the photovoltaic power generation system is also the main direction of future technological development. Grid connection can expand the scope and flexibility of solar energy use.

Grid-connected photovoltaic power generation means that the DC power generated by solar modules is converted into AC power that meets the requirements of the municipal power grid through a grid-connected inverter and then directly connected to the public power grid. It can be divided into grid-connected power generation systems with batteries and without batteries. Grid-connected power generation systems with batteries are dispatchable and can be integrated into or out of the grid as needed. They also have the function of backup power supply. They can provide emergency power supply when the grid is out of power for some reason. Photovoltaic grid-connected power generation systems with batteries are often installed. in residential buildings. Grid-connected power generation systems without batteries do not have dispatchability and backup power functions, and are generally installed on larger systems.

Photovoltaic power generation grid-connected centralized large-scale grid-connected photovoltaic power stations are generally national-level power stations. Their main feature is to directly transmit the generated energy to the power grid, and the power grid will uniformly distribute power to users. However, this kind of power station requires large investment, long construction period, and covers a large area. It has not developed much yet. Dispersed small-scale grid-connected photovoltaics, especially photovoltaic building-integrated photovoltaic power generation, are the mainstream of grid-connected photovoltaic power generation due to their advantages of small investment, fast construction, small footprint, and strong policy support.

1. There is a countercurrent grid-connected photovoltaic power generation system

There is a countercurrent grid-connected photovoltaic power generation system: When the power generated by the solar photovoltaic system is sufficient, the remaining power can be fed into the company** *Grid, supply power to the grid (sell electricity); when the power provided by the solar photovoltaic system is insufficient, the electric energy supplies power to the load (buy electricity). Since power is supplied to the grid in the opposite direction to the grid, it is called a countercurrent photovoltaic power generation system.

2. Non-countercurrent grid-connected photovoltaic power generation system

Non-countercurrent grid-connected photovoltaic power generation system: The solar photovoltaic power generation system does not supply power to the public grid even if the power generation is sufficient, but when When the power supply of the solar photovoltaic system is insufficient, the public power grid supplies power to the load.

3. Switching grid-connected photovoltaic power generation system

The so-called switching grid-connected photovoltaic power generation system actually has the function of automatic operation and two-way switching. First, when the photovoltaic power generation system generates insufficient power due to cloudy, rainy days or its own faults, the switcher can automatically switch to the power supply side of the grid, and the grid supplies power to the load; second, when the power grid suddenly loses power for some reason, The photovoltaic system can automatically switch to separate the power grid and the photovoltaic system and become an independent photovoltaic power generation system. Some switching photovoltaic power generation systems can also disconnect power supply to general loads and connect power supply to emergency loads when needed. Generally, switching grid-connected power generation systems are equipped with energy storage devices.

4. Grid-connected photovoltaic power generation system with energy storage device

Grid-connected photovoltaic power generation system with energy storage device: It is to configure storage according to needs in the above types of photovoltaic power generation systems. Can be installed. Photovoltaic systems with energy storage devices are highly proactive and can operate independently and supply power to the load normally when there is a power outage, power limit or failure in the power grid. Therefore, the grid-connected photovoltaic power generation system with energy storage device can be used as a power supply system for important or emergency loads such as emergency communication power supply, medical equipment, gas stations, shelter instructions and lighting.

Collapse