FLATCON® technology was developed at Fraunhofer ISE to a production-ready stage and is now manufactured by the institute’s industrial partner Soitec (formerly Concentrix Solar). Fresnel lenses are used in these FLATCON® modules to concentrate sunlight.
In other systems, we also employ mirror optics for concentrating sunlight. In very large systems, for example, the receiver is called a compact concentrator module (CCM), as a great many solar cells are arranged as closely together as possible. When the receiver area measures several square decimeters, the solar cells require active cooling. In addition to electrical energy, these solar cells generate thermal energy that can be used as process heat, or even for solar cooling or thermal sea water desalination.
If the receiver surface is even larger, measuring several square meters, the receiver can be used in a CPV solar power tower. Here, sunlight is focused onto the receiver by heliostats. In such systems, the solar energy is converted into electricity at a central point and the optics are isolated from the receiver.
One module concept that we investigate, which employs passive cooling, is that of the Cassegrain module. Here, sunlight from a parabolic primary mirror is concentrated onto the solar cell using a hyperbolic secondary mirror, meaning that very low module heights can be achieved.