Cooling down solar panels
You can probably imagine that a dark panel gets hot in full sun. Unfortunately, a warm panel produces less power. Because of the negative temperature coefficient, the voltage drops as the temperature rises. Is there anything we can do to give such an overheated PV system a helping hand?
Arnoud van Druten, managing director of Floating Energy (part of Sunprojects) agrees. “No material likes large, sudden temperature shocks. A panel on a floating island already has a few degrees of advantage over a panel on land due to the cooling effect of the water beneath it. If a panel is attached to a non-cooling surface, as is the case on a roof, the warming will only increase. Especially if there is little space under the panels to give the wind a chance to dissipate the heat.”
“In floating open and transparent PV projects, the coolness of the water can reach the panels through the air while allowing the wind to do its job of dissipating heat. With closed, floating systems, there is a limitation to this cooling effect due to the additional ‘insulation layer’ that the closed float forms. This is further reinforced by laying the panel flat on the float which limits the beneficial effect of air flowing past.” According to Van Druten, the heating also takes place much more moderately on the water, so that sudden temperature shocks do not occur, or hardly at all.