The owner was mystified, and to be honest, so were we for a moment. Fortunately, Priogen reads out lots of data, not just the end result. We also measure the performance of all relevant hardware as well, such as converters and the solar panels.
We know overheated panels produce less energy. In this case temperatures were approximately 30ºC, meaning the surface level temperature of a panel could rise up to 71ºC . Based on historic data we anticipated an underperformance around 3%. But that could hardly explain the 21% drop we were measuring.
After analysing all data sources we figured out the only logical explanation left. Would it be possible that too much dust had settled on the panels, ultimately blocking the sun? The more dry it gets, the more dust will evolve and settle down. It hadn’t been raining for weeks which is an unlikely scenario in the Netherlands. If the solar panels weren’t cleansed by the occasional shower, in theory the dust should be disturbing.
We asked the owner to sprinkle the solar panels, and guess what! Generation of power was up. And our client was shining.