There are many types of inverters, which can be categorized differently according to the use, principle, and applicability, which causes us to have a hard time choosing an inverter, below we will introduce you the difference between grid-tie inverter and common inverter and the related problems, hopefully it can solve your doubts.
Difference in the degree of dependence on the power grid: Grid-connected inverters have to be connected to the power grid, and when the power grid can work, the grid-connected inverters can be used normally. However, when the grid fails, the grid-tie inverter can’t be used either, resulting in the whole solar system stop working. More dependence on the grid. Ordinary inverters do not need to be connected to the grid; it can run all by itself independently without relying on the grid.
Difference of energy storage: Grid-connected inverter has no energy storage function, when there is power surplus, it will directly input the excess power into the grid. Ordinary inverter will have energy storage function, in the installation of ordinary inverter solar energy system has solar battery, the excess power stored in the solar battery.
Difference in structure: Grid-connected inverter module usually adopts full-bridge or half-bridge topology plus switching controller, while ordinary inverter module is mainly designed as a cascade of high-frequency DC-DC boost converter and full-bridge PI-controlled voltage source inverter.
The difference between the role of the mechanism: ordinary inverter will input DC boost; through the inverter bridge SPWM technology will be converted into AC power. Grid-connected inverters also boost the DC first, but it is regulated by switching controllers, such as for example IGBTs or MOSFETs to convert DC into AC.
Advantages: Grid-tie inverter itself may be cheaper than normal inverter, and it does not need batteries in the whole solar system, which reduces the cost of the batteries, compared to the cost of the batteries, grid-tie inverter will be a little bit lower, from the overall point of view, the total cost of solar energy system using grid-tie inverter is cheaper. Any excess power generated by solar energy is fed into the grid, which in turn extends the life of household appliances, even if the user receives a government subsidy. Grid-tie inverters maximize the use of solar energy and reduce the waste of solar energy.
Disadvantages: The use of a grid-tie inverter can make the solar system completely dependent on the grid, and when the grid fails, the entire solar system won’t work properly. Grid-tie inverters do not have energy storage, so they are dependent on the grid when there is a high demand for electricity in the home. Grid-connected inverters are more complex, more prone to failure and more troublesome to repair. It is not recommended to be used in areas with unstable power grid.
Advantage: Ordinary inverter will have its own energy storage system, during the peak period of household electricity consumption, it can directly use the energy storage system to supply electricity to the household without relying on the power grid. Like areas far away from the grid, a regular inverter will provide you with a reliable power supply. As long as the solar system does not malfunction, the solar modules will work normally.
Disadvantages: The solar system installed with a regular inverter will have solar battery installed in order to have a steady supply of electricity. However, the cost of solar cells is again higher, and the overall cost of the solar system will be higher. Because of the limitation of the storage capacity of the solar battery, there is a limitation on the utilization of solar energy. In addition, maintenance and replacement of the energy storage system will increase the cost. There is a certain amount of power loss during the storage process, which reduces the overall efficiency of the solar system.
The most direct role of an inverter is to convert DC to AC, but a grid-tie inverter will have other additional roles. A grid-tie inverter, through the output, will generate power from the solar panels, part of which will be for domestic use, and part of which will be fed into the grid, and the meter will generate reverse power, which can be used to take advantage of discounts at your you use grid power at a later stage. The output of the grid-tie inverter will not be connected to the solar battery, and in the case of no grid failure will be more continuous than the installation of a normal inverter solar energy system when using electricity, and most of the time there will not be a lack of power supply.
Grid-tie inverters do not have energy storage, but are connected to the grid so that you can use grid power when the solar power is insufficient. Common inverters have energy storage but are not connected to the grid and are relatively independent.
