What it is and how to choose the right one

Types of solar inverter

There are three main types of solar inverter – string inverters, microinverters and power optimisers:

1. String inverters

String inverters are the oldest form of inverter, using a proven technology that has been in use for decades. Solar panels are arranged into groups or rows, with each panel installed on a ‘string’. Multiple strings can be connected to a single inverter, which transforms the DC electricity produced by the panels into appliance-friendly AC electricity.

The downside of string inverters is that if the performance of one panel is reduced – for example by damage or shading, the performance of the whole array can be affected.

2. Micro inverters

Micro inverters are becoming a popular choice in residential solar systems. These are fitted to each individual solar panel and convert DC to AC on the roof, removing the necessity of a separate inverter.

Because the conversion is performed this way, if one or more panels are affected by shade then it doesn’t have an impact on the panels that are still in sunlight. It’s also possible to monitor performance levels of every single solar panel.

Micro inverters are often considered as a way to install more solar panels on a roof. Panels that may be in partial shade for some of the day will not affect the performance of the other panels that remain in sunlight more of the time.

Micro inverters are still a relatively new technology and are generally more expensive than other inverter types, however, this additional cost may be offset by increased energy production.

3. Power optimisers

Offering many of the benefits of microinverters, but slightly less expensive, power optimisers are also located on each individual panel. But instead of converting DC to AC at roof level, they move the DC to a string inverter. With power optimisers, you should be able to monitor the performance of each panel via an online portal.