A mate of mine in the solar industry has a theory: that many solar panels sold in Australia do not meet the specifications printed on their labels. His belief comes from the fact that he has personally tested a whole heap of imported panels and has not yet found one that meets its power tolerance spec!
My hunch is that many of the cheaper ‘Tier 3′ panels on the market may not meet their power tolerance specs, but I’ll be very surprised if the more expensive Tier 1 panels don’t.
For those who don’t know, the power tolerance gives you a tolerance for the actual power output of the panel, compared to its nameplate rating. Basically, if a panel that is rated as 250W has a power tolerance of +/- 5% then the manufacturer is guaranteeing that the actual power will be above 237.5W and under 262.5W. [Continue reading…]