An solar inverter is an important component within a solar power system. For home solar systems, the main function of the inverter is to convert the DC power from the panels into AC power for supplying electricity. Installing different types of inverters can have a big impact on the efficiency and cost of the solar panel system. Therefore, when choosing an inverter for a solar energy system, it is necessary to consider a variety of factors to make a comprehensive choice.

1. Micro inverter and string inverter

1.1 Solar Micro inverter

Microinverters are usually installed on the back of each solar panel or next to the solar panel bracket, which can convert the DC power from each panel into AC power individually without the need of installing a separate series inverter. This feature makes it possible that even if the power generation of one solar panel fails, it will not affect the overall power supply capacity.

1.2 Solar String Inverter

The installation of a string inverter requires that the solar panels be arranged in interconnected batteries, and these strings of solar panels can be connected to the same inverter, which is called a string inverter. These string inverters connect a certain number of solar panels together, and if one of the solar panels has a problem generating power, then the power generation of all the panels in the string will be reduced.

2. How to choose the type of solar inverter?

2.1 What are the differences between micro inverters and string inverters?

2.1.1 Installation cost

String inverters have a longer history of use and are the most affordable option. Microinverters, on the other hand, offer more superior performance and are correspondingly more expensive.

2.1.2 Impact on the overall solar power system

Since the micro inverter is mainly responsible for the conversion of DC and AC power from a single solar panel, each inverter belongs to a parallel connection. So when there is a problem with the power generation of a single panel, it does not affect the overall power generation efficiency. This feature enables the power generation capacity of each solar panel to be fully utilized. The combination of each set of panels and inverters can be maximized.

While the solar panels within each string of the string inverter battery set are connected by a series connection, once there is a problem with the power generation of one of the panels, the power generation efficiency of the whole string of panels will be affected.

2.13 Problems such as post maintenance and warranty

Consider the possible failures of different inverters at a later stage and the need for maintenance issues. Typically, the warranty period for solar panels is around 25 years and the warranty offered by microinverters is about the same as that of solar panels. String inverters, on the other hand, only offer a warranty of about 15 years, which means that using a string inverter may make it necessary to replace the inverter once during the warranty period of the solar panels.

However, the cost of replacing a microinverter is higher than replacing a string inverter when both are out of warranty. This is due to the fact that microinverters are more complex in structure and alignment, making troubleshooting more difficult and requiring specialized maintenance personnel to access the interior of the roof for repairs.

2.2 What are the benefits of choosing a microinverter?

Compared to string inverters, microinverters are much smaller and can be mounted individually on the back of each solar panel, thanks to which the overall efficiency will not be affected by the shading of a single panel. And, thanks to its parallel structure, it makes it easier to add more solar panels later.

2.3 What are the benefits of choosing a string inverter?

String inverters have a simple structure, only one inverter needs to be installed for the whole solar system, and this simple structure is more conducive to troubleshooting in the event of a malfunction. Therefore, the cost of later maintenance will be lower. Secondly, it is less expensive and more suitable for users with lower budget.

2.4 What factors should be considered when choosing a suitable inverter?

2.4.1 Solar battery setup

Although the optimizer structure of both microinverters and string inverters can be compatible with battery storage, but considering that users may need two different solutions, DC-coupled batteries or AC-coupled batteries, it is necessary to choose different types of inverters. For example, microinverters are usually only suitable for AC-coupled batteries.

2.4.2 Considering the specifics of the house

Since the main reason for the reduction of power generation from solar panels is the decrease of direct sunlight to the panels due to the shading of nearby tall objects, it is a better choice to choose microinverters for houses that have been in the state of shading for a long time. And the roof structure of some houses is more complicated, there are solar panels installed in multiple areas and in different directions, which are difficult to be connected to form a string structure, and this time also requires the use of microinverters.

On the contrary, some roofs with open surroundings and flat and simple structures are more suitable for using string inverters.

Summary

Choosing the right inverter for your system can improve the performance of your solar power system and maximize the use of the collected solar energy. However, how to pick the most suitable inverter for you depends mainly on the specific size of the solar power system, the intensity of sunlight in the location of the house, and the household’s electricity consumption.