What is Off-grid Solar Inverter and working principle?

Off Grid Inverter is a technical solution for inverters, and its working principle is the same, converting the direct current (DC) generated by solar panels into alternating current (AC). Unlike other technical solutions, the core point of off-grid inverters is that the power output by the inverter is not connected to the grid, but to the load, directly driving the load to supply power.
Due to the application characteristics of off-grid inverters, there are relatively few application scenarios, mainly in some remote areas, where there is no grid connection conditions, the grid connection conditions are poor, or there is a need for self-generation and self-use of electricity. The off-grid system emphasizes “self-generation and self-use”. Due to the small number of applications of off-grid inverters, there are few technical research and development. This has led to less and less research and development of this type of inverter, showing a shrinking trend. However, the functions of off-grid inverters and the technologies involved are not simple, especially the coordination with energy storage equipment, and the control and management of the entire system are complicated. The system composed of off-grid inverters, solar panels, energy storage devices, loads and other devices is already a simple microgrid system. The only point is that the system is usually not connected to the grid and is an “island system”.

Off-grid inverters are mainly used to solve the problem of power supply and lack of grid connection, so that they can store as much electricity as possible when the grid and photovoltaic solar panels provide two kinds of electricity. At night or when the power supply is insufficient, it automatically switches to energy storage equipment for power supply to ensure stable power use.

Off-grid inverter advantage

1. Allows you to store the electricity generated by solar panels in batteries, and at night, the stored electricity will be used to power loads such as houses
2. Self-sufficient in electricity, and will not be affected by power outages or failures in the power grid
3. No longer need or pay less electricity bills, because the power system does not need to use power from the grid all the time
4. Independent operation, not affected by grid fluctuations
5. With island protection function, when the grid fails, the inverter can automatically cut off the connection with the grid
6. Off-grid inverters can convert renewable energy such as solar energy and wind energy into AC power and output it, which helps to promote the development of renewable energy
7. For areas without access to the grid, off-grid inverters are an effective way to solve power supply problems
8. Off-grid inverters have the characteristics of strong flexibility, energy saving and environmental protection
9. It can store electricity, has power independence, and high sustainability.

Off-grid inverter disadvantages:

1. If there is insufficient light, your battery may not be fully charged and the power may be cut off.
2. Purchasing and installing such an inverter system can be expensive
3. The stability and reliability of the off-grid system need to be improved;
4. Due to the need to use energy storage batteries, the cost of off-grid inverters is relatively high;
5. The capacity of off-grid inverters is relatively limited, and the output voltage, current and other parameters are limited, which makes it difficult to meet the use requirements of high-power electrical appliances.
6. The price is high, and the battery needs to be replaced every 5–10 years. There is a lot of noise and no policy subsidies.

Use scenarios

1. Stable power supply is required
2. A place with plenty of sunshine, far away from the public power grid, or insufficient power supply from the power grid