Microinverters & Optimisers

Solar PV technology continues to evolve and many people can benefit from the latest microinverter or optimiser technology.

An inverter is the device that converts Direct Current generated by the solar panels to feed into the main supply as 50Hz Alternating Current. Traditional inverters are fed by one or two strings of solar panel feeds. An issue with this is that if just one panel experiences shading then all the others in that string are brought down to its level and not able to operate at 100% power output. For an unshaded roof this is not a problem, but for a roof with even partial shading (e.g. from a chimney) this can impact on the power output.

Two different approaches have been adopted by the inverter manufacturers:

Optimisers

Optimisers work in a similar fashion to a traditional inverter system but have a special unit placed under panel which allows all panels in a string to operate at maximum efficiency. A single inverter is still required.

Microinverters

A cleaner solution is to get rid of the centralised inverter unit altogether (making for a very clean installation in the loft!) and each solar panel is attached to its own inverter, which sits underneath it. This provides maximum efficiency and copes very well with partial and varying shading.

enPhase, the main manufacturer adopting the microinverter approach, supply a monitoring box  (called the Envoy Gateway – extra charge) that allows their microinverter systems to plug into the internet and supply (no annual charge) sophisticated monitoring down to the individual panel level. They also automatically monitor the installation and email you if they ever see any problems/issues

For the solar energy obsessive there are also free apps that allow you to see your solar PV data (live and historic) on your smartphone or tablet!