According to the existing photovoltaic power generation projects on the market, combined with different application scenarios, solar photovoltaic power generation systems can be roughly divided into five types: grid-connected power generation systems, off-grid power generation systems, off-grid energy storage systems, and grid-connected energy storage systems and a variety of energy hybrid micro-grid systems.

And off-grid energy storage system

It is composed of photovoltaic modules, solar energy and off-grid integrated machine, battery (energy storage), load, etc. It is widely used in scenarios such as frequent power outages or photovoltaic self-use without surplus electricity, self-use electricity price is more expensive than on-grid electricity price, peak electricity price is more expensive than valley electricity price, etc.

The photovoltaic array converts solar energy into electrical energy under the condition of light, and supplies power to the load through the solar controller inverter integrated machine, and at the same time charges the battery; when there is no light, the battery supplies power to the solar controller inverter integrated machine. Then supply power to the AC load function. Dual mode switching to ensure power supply requirements.

Photovoltaic grid-connected energy storage system

It consists of photovoltaic modules, solar controllers, batteries, grid-connected inverters, current detection devices, loads, etc. It can increase the proportion of spontaneous self-use.

When the solar power is less than the load power, the system is powered by the solar power and the grid together. When the solar power is greater than the load power, the solar power supplies the load while storing the excess electricity through the inverter.

Microgrid system

A power distribution network composed of distributed power sources, loads, energy storage systems and control devices. The distributed energy can be converted into electrical energy on the spot, and then supplied to the local load nearby.

The microgrid system is an autonomous system capable of self-control, protection and management. It can not only be connected to the external power grid, but also can operate in isolation, which greatly solves the problem of distributed power grid connection and promotes the integration of distributed power The large-scale access of renewable energy is an efficient supply of multiple forms of energy for the load, and a smart grid system that realizes the active distribution network.

Secondly, let's talk about the difference between photovoltaic grid-connected and off-grid?

Photovoltaic grid-connected systems rely on the power grid and adopt the working mode of "spontaneous self-use, surplus electricity connected to the grid" or "full grid connection", while off-grid systems do not depend on the grid, relying on "storage while using" or "store first and use later". working mode.