Micro-inverters VS String inverters

January 24, 2016

The inverter is the part of the solar system that converts direct current (DC) power produced by the solar panels into alternating current (AC) power, which is the only usable form of electricity, needed to power your appliances and utilities. Now, a common debatable decision for people when purchasing solar is deciding whether to go with string inverters or micro-inverters. Let us help you understand the difference between the two so you can decide which is better for you!

The String Inverter (Central)

What’s does “string” mean?

For example, if you have 10 solar panels in your solar system, and the panels are divided into 2 groups, 5 panels for each group, each set of 5 panels is called a string which are connected through a parallel circuit which is connected to the inverter.

String Inverters

String inverters have been popular for a very long time and they’re very cost-effective, however, they are only recommended when your panels are not subjected to shading at any time of the day, or when the planes are not facing different directions.

If there’s any shading during the day, the power outcome from the entire string will be at its minimum output of production. This is the same situation for multiple planes; the efficiency will not be at its best.

The Micro-Inverter

Micro-inverters are much more expensive than string inverters but they are recently becoming very popular because of their efficient and simple installation.

A micro-inverter is a small box installed under or near each panel converts the DC energy into AC energy right at the panel.

Micro Inverters

The Advantages of the Micro-Inverters Over the String Inverters:

  • In a string inverter if one panel malfunctions, you will not be able to determine which one it is and you will have to check each of them separately. However, with micro-inverters, if a panel malfunctions, you will know right away which panel it is, and it will not any other part of the system.
  • Micro-inverters have power optimization that results in 15% more power production for each panel.
  • String inverters do not perform best if there is any shading, whereas micro-inverters will not be affected and can and will keep working efficiently.
  • Micro-inverters are a lot safer to handle than string inverters because string inverters deal with much a higher voltage level of DC power, which can be very dangerous.
  • String inverters are very difficult to install and if any damage is caused during installation it is not covered by the warranty.
  • The micro-inverters, despite being a lot more expensive, have a 25-year warranty and an average lifetime 32 years! String inverters are yes, less expensive, but they only have a 10-year warranty and do not have a high life expectancy.
  • String inverters need to be wired every 10-12 years which costs more money and labor in the long term.