What is the difference between off-grid system and grid-connected solar system?

- Feb 10, 2019-

Photovoltaic off-grid power generation is a solar power system with a battery. The electricity generated by the solar panel is stored in the battery through the controller, and then the power is supplied to the load through the controller or the inverter. Solar off-grid power system is not connected to the grid and can be operated independently from the grid, so it is also called stand alone solar power system. For example, our common solar street lights are typical demonstrations of photovoltaic off-grid power generation applications.

 solar power systems

PV grid-tied power generation uses PV inverters to invert solar DC power into pure sine wave AC with the same frequency and phase in the public grid. It is connected to the public grid through the boost or low-voltage side to schedule the use of electric energy.


The installed capacity of the solar independent power system can be large or small, and the configuration scheme can be adjusted at any time, so that the scale is too large and the investment is wasted. Where the power infrastructure is weak and the electrodes are unstable, the photovoltaic off-grid system can also achieve complementary functions with the mains. Fields, farmers and small planting posts in remote and remote areas without electricity use solar off-grid power generation, which can solve the daily lighting of users and the simple electricity demand of household appliances.


The working principle of grid-connected off-grid power generation is to use PV modules (solar panels) to generate current under solar radiation, to store solar energy in the battery through the solar charge controller, and then to output stable direct current for DC load (such as street lamps). And through the inverter to inverter into the same voltage and phase of the grid as the AC output for AC load. Off-grid power generation system does not depend on the independent operation of the grid, so it is also called solar independent power generation system.