High-Concentration Systems (HCPV)

We develop high concentration photovoltaic systems that allow III-V multi-junction solar cells to be used for terrestrial applications. To do so, we analyze and assess optical components that concentrate sunlight by a factor of 300-1000 before it is converted into electrical energy using III-V multi-junction solar cells. Within the field of concentrator systems, we work to develop and refine the entire technology chain from solar cells, concentrator optics and module production through dedicated electronics to complete systems and monitoring. One key integral part in this technology is the development of concentrator modules, which is coordinated at Fraunhofer ISE in the Concentrator Technology Evaluation Center (Con-TEC). Research at Con-TEC primarily focusses on optimizing design, manufacturing processes and CPV module reliability. Our expertise in the field of thermal, optical and electrical simulation is offered to our clients, and we optimize and develop processes and innovative systems.

For more than two decades, we have been developing our lens based FLATCON® technology devised at Fraunhofer ISE. The module uses Frensel lenses produces with the silicone-on-glass (SoG) technology to concentrate the solar radiation. On this technology, our novel hybrid module EyeCon is based. It converts direct, diffuse and - with bi-facial PV cells - even the rear irradiance into electricity to increase the power output further. For cost reduction, we investigate micro-CPV modules.
Beside of modules with lenses as primary optics, we develop module concepts using mirror optics as concentrators to reach high geometrical concentrations. On system level, we are researching the co-generation of heat and electricity in concentrating systems with the goal of reaching system efficiencies of over 70%.

A variety of experimental methods are available for characterizing CPV components.

Within the field of high concentration PV systems, we develop concentrator modules and systems. We follow an holistic approach that includes optical, thermal, mechanical and electrical aspects and offer:

• Integration and testing of innovative new cells in concentrator modules
• Modules with solar cells from few hundred micrometres to few square centimetres
• Experimental investigation of new concepts and components (e.g. integration of secondary optics) for CPV
• Design optimization and analysis using finite element methods (FEM) and computational fluid dynamics (CFD)
• Pilot and small production batches using automated manufacturing technologies (e.g. pick & place; bonded, adhesive and soldered joints, electrical interconnection)
• Reliability and long-term stability testing
• Lab and field measurements including power rating