A solar inverter is an electronic equipment that converts the electricity produced by solar panel (DC power) to electricity that is sent to the utility grid or a household appliance (AC power).
There are 3 kinds of inverters used in solar panels today:
- Micro inverters
- Central inverters
- String inverters
What are string inverters?
String inverters converts the DC electricity to AC for multiple panels, i.e., a string of panels. String inverters are commonly used in the case of home and commercial solar power systems. It typically has an efficiency of 97.5 – 98.5%.
How do string inverters work?
As mentioned earlier, the solar panels which are arranged to be ‘strings’ feed all the power they produce into a single inverter. From this inverter unit, the electricity is customized to the needs of the end-user.
Example: Let us assume there are 50 panels on a rooftop installation. These 50 panels are arranged into 10 groups of 5 each. These 10 groups are referred to as a ‘strings’. The 10 ‘strings’ of panels are connected in parallel which are eventually connected to a single inverter unit.
Although the type of inverter used depend on the type of application, string inverters have the widest range of applications in terms of residential to large scale commercial application. If you have a ground-mounted or large roof installation with one array and all the solar panels have the same orientation, it is advised to go with string inverters.
It can be said that string inverters provides a balance between central and micro-inverters. Their moderate size and stringed arrangement makes them easier to install and maintain compared to central inverters. In comparison to micro-inverters, they offer advantages in terms of expandability and cost per watt peak.