Why fans in solar inverters are a good thing

Solar Inverters contain a lot of electronic circuitry and this needs to be kept cool in order to function properly. As a general rule heat has a significant influence on the lifespan of electronic components and every 10 degree C increase cuts their lifespan by 50% – this is why a lot of cheap solar inverters fail during the hot summer months.

Inverter manufacturers such as Fronius use a small fan or fans to actively cool the components which is known as active cooling whereas others (normally cheaper options) simply using heat sinks which is known as passive cooling.

Which is best for our hot summers?

Active Cooling

active cooling

With active cooling the fan(s) cool all the electrical components and heat sinks effectively lowering the temperature and avoiding any hot spots.

This creates less stress on the components which in turn extends their lifespan.

Some may argue that using a fan introduces a point of failure and if the fan fails the inverter will not function correctly. This maybe true however as the Fronius service agent for the Sunshine Coast we have never had to change a fan in any Fronius Galvo, Primo or Symo inverter and if, in the future, a fan does need to be replaced this can be done very quickly.

Passive Cooling

passive cooling

Passive or natural cooling relies on heat being dissipated naturally without any fan. This lack of air circulation creates hot spots which in turn reduces the lifespan of the solar inverter.

Power derating

power derating

If a solar inverter overheats it will reduce power output in order to reduce the stress on components.

Active cooling has a much stronger cooling effect than passive cooling and inverters which rely on passive cooling will derate earlier and at a much steeper rate than actively cooled inverters. This can result in significant power losses on hot days.


It is clear that the benefits of active cooling far outweigh the small risk of a fan failure in the future. This doesn’t however stop some sales people from claiming that passive cooling is far better than active cooling “as the fans all fail after a few years” this is just another sales ploy used by unscrupulous sales people which should be taken with a pinch of salt and disregarded.

For quality Sunshine Coast solar power systems contact us today