The FLATCON® module technology was developed at Fraunhofer ISE. Fresnel lenses are used to concentrate sunlight. Advancing this module concept, we currently develop the EyeCon module. This hybrid CPV-PV module uses small concentrator multi-junction solar cells to collect the direct sunlight radiation and silicon PV cells for diffuse light. In this way the highest power output per module area was achieved. For example, the power output of our EyeCon module with 4 junction concentrator solar cells and bifacial silicon solar cells is beyond 350 W/(m²module area).
For cost reduction, we develop a new micro-CPV module where manufacturing technologies from the LED and display industry are used. In micro-CPV, the solar cells are less than a square mm in size which requires highly accurate placement of a large number of devices. Here, we rely on parallel placement of hundreds of devices combined with self-alignment to an underlying circuit board. Both, lenses or mirrors, can be used to produce such micro-CPV modules (see figure on the left). The advantage of mirrors is that there is no chromatic aberration and due to short focal lengths, we achieve low module heights. The solar cell can be placed on-axis in the focal point or in a Cassegrain mirror arrangement.
Besides, we also develop receivers which are specifically designed to generate electric and thermal power. Such dense array receivers or compact concentrator modules (CCM) are used for example in solar towers which collect sunlight from a field of heliostat mirrors or paraboloid dishes. These systems require active cooling but at the same time allow to extract useful heat which can be used in industrial applications or to store energy. We have also investigated hybrid systems with solar cooling and thermal sea water desalination.
We employ a variety of simulation tools, such as network simulation for solar cell development or ray tracing for optical design, when developing and analyzing new components.
To support our customers, we use our extensive experience in module development to improve their specific module designs e.g. to increase performance or to implement new manufacturing technologies for industrial production.
Fraunhofer Institute for Solar Energy Systems ISE
