The Difference Between Power Optimisers and Micro-inverters

String Inverters
The Direct Current (DC) your solar panels generate is transmitted to a string solar inverter in traditional solar energy systems. Then the DC power is converted into AC power, which is then utilised by appliances in your house or exported back to the utility grid. Fronius Symo is an example of traditional string inverters.

Micro-inverters and power optimisers, twist the standard solar panel system setup. Micro-inverters fully replace the need for a string inverter, while power optimisers work alongside the string inverter to increase solar panel output in case of roof shadow issues.

Micro-Inverters
How It Works:
Instead of one central inverter, solar energy systems with microinverters have an inverter on the back of each solar panel. These micro-inverters carry out the same function as a standard string inverter (conversion of DC power to AC power), negating the necessity for a standard inverter. Enphase is mostly a choice in Australia.

Benefits:
With a string inverter, if one solar panel has shade and gives lower output, all solar panels can potentially suffer from the same reduced output.

As the DC-AC conversion of micro-inverter systems takes place at the panel level, the solar panel output of each module isn’t affected by other modules. Micro-inverters also let you monitor the efficiency of individual solar panels.

Disadvantages:
Micro-inverters can cost almost twice as much as standard string inverters.

As they are placed along with solar panels on the roof, micro-inverters systems are exposed to extreme climate conditions.

Sometimes due to higher temperatures in the summer season, your micro-inverters will be put under an incredible amount of stress and may not operate as designed.

Power Optimisers
How it Works:
Just like micro-inverters, a power optimiser is a small box connected to the back of each solar panel. However, unlike micro-inverters, power optimisers work with string inverters to enable the maximum solar panel efficiency.