Cooling techniques for solar panels with increased yield
The sun is the largest source of renewable energy. Solar panels are therefore one of the most important technologies for generating sustainable electricity. To realize the transition to a fully sustainable energy supply, it is important to realize PV systems with the highest possible yield.
Background
The average efficiency of modern solar panels is currently above 20%. Various loss processes limit this efficiency and the ultimate yield of solar panels. One such process that causes losses in practice is heating of the solar panels. When solar panels heat up, they lose voltage. This means that solar panels generate less electricity on hot, sunny days. Cooler days with lots of sun are better for the yield of solar panels, but even on these days solar panels can still heat up significantly, resulting in a loss of yield. One of the ways to increase the yield of PV systems is to ensure that solar panels heat up less. In this project, cooling techniques are developed that increase the annual yield of PV systems.
Goal
In this project, heat-resistant pigments and cooling coatings are developed that keep solar panels cooler. In warm and sunny weather, the temperature of a solar panel can rise to 75 °C(!). This means that approximately 25% of the potential electrical energy can be lost. By using the cooling techniques in this project, the yield of PV systems can be increased by approximately 5% on an annual basis.
Short discription
TNO and Solarge are working together to develop cooling techniques for Solarge's lightweight and circular solar panels. Heat-resistant pigments are implemented in the plastic facesheets used by Solarge in its solar panels. This means that the underlying solar cells heat up less and heat transfer to the environment is maximized. In addition, a coating is being developed that partly reflects heat radiation (infrared). This radiation does not contribute to the generation of electrical energy, but only heats the panel. In addition, the coating is able to radiate heat back into the room. This achieves an extra cooling effect. In principle, this coating can be applied to any type of solar panel.
Outcome
After this project, Solarge can use heat-resistant front sheets in its solar panels. These panels will heat up less and therefore have an increased yield compared to the current panels without the pigments. In addition, a cooling coating has been developed that is not only able to reflect heat radiation, but also radiate extra heat. This can further increase the yield of solar panels. The techniques can in principle be applied to all solar panels on the Dutch market. They can be applied not only to new panels, but also to already installed ones. This allows greater yields to be achieved from current and future PV systems. The direct, total savings on the SDE++ achieved with this project is almost €17 million.
