The difference between grid-connected and off-grid solar power systems

Solar photovoltaic power stations are divided into off-grid (independent) systems and grid-connected systems, and now I will tell you the difference between the two: When users choose to install solar photovoltaic power stations, they must first confirm the use of off-grid solar photovoltaic power stations or grid-connected solar photovoltaic power stations, the use of the two functions are not quite the same, of course, the composition of solar photovoltaic power stations are not the same, the cost is also very different.

(1) Off-grid solar photovoltaic power station, also known as independent photovoltaic power station, is a system that does not rely on the power grid and operates independently. It is mainly composed of photovoltaic solar power panels, energy storage batteries, charge and discharge controllers, inverters and other components. The electricity emitted by photovoltaic solar power generation panel flows directly into the battery and is stored. When it is needed to supply electrical power, the direct current in the battery flows through the inverter and is converted into 220V alternating current, which is a repeating cycle of charge and discharge process. This kind of photovoltaic solar power station is widely used because it is not limited by the region. It can be installed and used wherever the sun shines. Therefore, it is very suitable for remote areas without power grid, isolated islands, fishing boats, outdoor breeding bases, and can also be used as emergency power generation equipment in areas with frequent power outages.

Off-grid photovoltaic solar power stations account for 30-50% of the cost of the generation system because they must be equipped with batteries. And the service life of the battery is generally in 3-5 years, after which it has to be replaced, which increases the cost of use. Economically speaking, it is difficult to get a wide range of promotion and use, so it is not suitable for use in places where electricity is convenient.

However, it has strong practicability for households in areas with no power grid or frequent power outage. Especially in order to solve the lighting problem when the power failure, you can use DC energy-saving lamps, very practical. Therefore, off-grid photovoltaic solar power stations are specifically for use in ungrid areas or areas with frequent power outages.

(2) Grid-connected photovoltaic solar power station means that it must be connected to the public power grid, which means that the solar photovoltaic power station, the household power grid and the public power grid are connected together. This is a photovoltaic solar power system that must rely on the existing power grid to operate. Mainly composed of photovoltaic solar power panel and inverter, photovoltaic solar power panel directly converted into 220V-380V by the inverter

Alternating current is also used to power household appliances. When rooftop solar plants produce more electricity than appliances use, the excess is sent to the public grid. When the output of the home photovoltaic power station cannot meet the needs of household appliances, it is automatically replenished from the grid. The whole process is intelligently controlled, with no human switch on or off.