The solar inverter is one of the important basic components in the realization of a solar power system to supply power to the home. Its main function is to convert the direct current (DC) emitted from the solar panels into alternating current (AC) and supply it to the load. There are many types of inverters, among which micro inverters are being installed in more and more solar power systems due to their excellent performance.

1. What is solar micro inverter and how does it work?

Microinverters are small power electronic devices that are often installed in solar panel systems. The key role of a microinverter is to convert the direct current (DC) generated by solar panels into alternating current (AC) that can be used directly on the grid.

A distinctive feature of microinverters is that each panel of a solar panel system in which a microinverter is installed will contain a microinverter. This unique independent installation can maximize the power generation benefits of each panel, while ensuring that the overall system operation will not be affected by a single panel.

2. What are the advantages of using microinverters?

2.1 Panel-level monitoring

In contrast to the array-level monitoring that other inverters are equipped with, microinverters usually provide data monitoring for each panel. When a solar panel fails, other types of inverters can only roughly determine the difference between the faulty panels, and specific troubleshooting and maintenance still need to climb up to the roof to check one by one, whereas the panel-level monitoring adopted by micro-inverters can directly troubleshoot the problem through the system panels, which is undoubtedly a more convenient and more cost-saving way of maintenance.

2.2 Longer service lifespan

Compared with other types of inverters, microinverters have a longer service life, usually around 25 years. This warranty is similar to that of solar panels, which eliminates the cost of a second installation in the middle of the solar panel’s life.

2.3 Fast energy shutdown

In addition to converting DC power into AC power supply, in the event of an emergency that requires shutting down the solar panel system, the microinverter can help to urgently shut down the solar photovoltaic power generation system, cut off the power supply that may cause a fire, to avoid hindering the rescue operation in an emergency situation and cause more damage.

2.4 No specification limitation

Since the microinverter is mounted independently on each solar panel, the total input and output specifications of the solar panels on each string and column do not need to be considered when installing the inverter. In addition to eliminating the limitation of power specifications, the independence of each inverter enables the overall solar panel system to be arranged into any pattern during installation, avoiding a large number of tangled and overlapping wires during wiring setup, which reduces the complexity of the installation while reducing the additional costs and avoiding the reduction of system efficiency caused by a large number of long cables.

3. Which solar power systems need to install microinverters?

First of all, if your solar panel system is subject to more shading from nearby obstacles or if the orientation of the solar panels does not agree, a microinverter is generally required. The most important reason for this is that, regardless of shading or orientation, when the efficiency of some of the solar panels is affected, the independence of the microinverter allows the less efficient panels to be separated from the rest of the panels, thus ensuring that these panels do not affect the efficiency of the entire solar photovoltaic power generation system.

Secondly, when your roof space is limited and the mounting structure of the solar panels is complicated, you need to install micro-inverters. This is due to the smaller size of the micro-inverter, which saves limited space on the roof and reduces the difficulty of troubleshooting on the roof for maintenance personnel at a later stage.

Finally, users who want panel-level monitoring may also choose to use microinverters.

4. How to choose the most suitable microinverter

4.1 By comparing the conversion efficiency of microinverters

The efficiency of microinverters is different from that of solar panels. The size of a microinverter’s efficiency is measured mainly by the energy loss it causes when converting DC power into AC power. When the efficiency of the micro inverter is greater, this also means that the energy loss caused by its conversion process is smaller. Therefore, choosing the right microinverter can reduce the power loss caused by the inverter.

However, it is worth noting that the efficiency measurements of inverters are usually tested under ideal laboratory conditions, and weather conditions may cause the efficiency of the inverter to change when it is actually installed on a solar panel system.

4.2 Comparing microinverter sizes

In order to accommodate different sizes of solar panels, it is necessary to equip them with appropriately sized microinverters to avoid excessive clipping.

4.3 Choose different power distribution methods

For microinverters, there are usually two different power distribution methods. They are single-phase and three-phase. Microinverters using a single-phase system are usually cheaper, and the DC power from the solar panels will only be output to the outside through one power line. Microinverters that use a three-phase system, on the other hand, will send the DC power outward through three power cables. In comparison, a three-phase microinverter can transmit more power, but it is also more expensive.