PERC Solar Panels – what does PERC mean?

Over the last 10 years of installing solar panels I have heard a lot of spurious claims about the benefits of different types of solar panels, in the early days it was thin film amorphous panels vs mono-crystalline, then came the great, which is better mono vs poly debate and now it is your panels have to be PERC.

This term is overused by some solar salesmen who don’t really understand what it means or whether it makes any difference.

Solar panel manufacturers have been striving to improve the efficiency of solar panels for years. When we started to sell REC Peak Energy solar panels which are poly or multi-crystalline (and for the record a good mono panel is as good as a good poly panel – there is no difference!) they would only produce 205watts, over the years REC made numerous small improvements to their manufacturing processes and today these panels produce 275watts which is a significant improvement.

However REC realised that they had reached the end of the line with this technology so they started to manufacture a PERC panel, the REC TwinPeak 2 panel.

PERC stands for Passivated Emitter and Rear Cell and is not a new technology, it was developed by the University of New South Wales in 1983 and it enables solar panels to be a lot more efficient by simply reflecting some light off the back of the solar cell so that it has an additional chance to create electricity.

By combining PERC and split cell technology manufacturers such as REC have increased the wattage of solar panels to 300watts and higher however are they better than the traditional REC Peak Energy solar panels? The short answer is no, they are simply more efficient at converting sunlight into electricity.

So does efficiency matter? Again the answer is no. If you are short on roof space you could choose a higher wattage panel as you will need a smaller roof area to install the required solar power system. If you are not short of roof space then efficiency means nothing at all.

Consider these 2 solar panels, both are 300 watt panels however panel B is smaller than panel A and is therefore more efficient however both panels will only produce 300 watts. You don’t get more electricity from a more efficient solar panel you just need less space.

In summary don’t be suckered in by the sales spiel – PERC panels are no better than non PERC panels and in some cases they are a lot worse as they all suffer from LID (Light induced degradation) to varying degrees. To avoid LID completely you will need to purchase a panel with N-type solar cells which uses PERT (Passivated Emitter Rear Totally Diffused) technology such as the REC N-Peak solar panel.

A quality solar panel manufactured by a quality company such as REC is worth the small additional cost and I for one would rather install a tried and tested product such as the REC Peak Energy panels than a “new” technology panel from another manufacturer.