Dyness Knowledge | Hybrid + off-grid output of home energy storage

The off-grid output capability of a hybrid inverter refers to its ability to operate independently of the utility grid in the event of a blackout or off-grid. This means that hybrid inverters can use energy stored in batteries or other renewable sources such as photovoltaic modules to power off-grid loads.

Usually, the off-grid output function of the inverter is realized by a built-in off-grid output unit or an external off-grid output unit in the inverter.

Most domestic inverter suppliers build the off-grid output function into the solar-storage inverter and integrate it into an integrated off-grid inverter. This kind of inverter has two output ports, grid-connected and off-grid, and has strong adaptability, especially for areas with complex application scenarios or scenarios where multiple application modes coexist. The integrated system saves installation space and facilitates installation and maintenance.

Schematic diagram of a hybrid inverter built-in off-grid output unit

For areas with relatively single application scenarios, this type of inverter system adds additional cost burden due to the relatively high cost of hardware and testing.

The off-grid power supply unit is independent of the solar storage system other than the inverter, and the corresponding off-grid power supply unit can be selected according to specific needs. It is better suited to the household power distribution system, and the coverage of household off-grid loads is relatively wide. From the perspective of system solutions, it has a stronger adaptability to the entire market.

Schematic diagram of external off-grid output unit of hybrid inverter

However, this split system generally has two obvious defects.

For areas that require off-grid power supply, because off-grid power supply units need to be configured separately, the cost of the entire system will increase. And the installation is relatively complicated, and the installation requirements are relatively high. In the actual operation process, the flexibility will be reduced.

For external off-grid power supply equipment, it is difficult to realize UPS-level off-grid switching, and has poor adaptability to some important equipment that cannot be powered off.

In short, the inverter's built-in off-grid output unit or external off-grid output device has its own advantages and disadvantages, and users need to make a reasonable choice according to their own needs and application scenarios.