Background
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| Uniform Irradiance distribution after adding Köhler homogenizer |
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Effective optical imaging design is critical for a solar energy system such as concentrating photovoltaic and concentrating solar thermal. One of the design goals is to produce high solar flux and a desirable uniform irradiance on the photovoltaic cell, which further converts light into electrical output effectively.
The previous solution was to use a kaleidoscopic prism. However, the kaleidoscopic glass mixer is bulky, the material is expensive for mass production, and the mounting is difficult. A promising new solution based on combining aplanatic optics with Köhler illumination has been invented.
Description
Researchers at the University of California, Merced have improved the optical system design based on principle of combining aplanatic optics with Köhler illumination. The new type of solar concentrator effectively produces a desirable uniform irradiance on the solar cell by placing a Köhler lens near the focal plane of the aplantic sytem. This is different from the previous design by the group, where the Köhler element was integrated into a two reflector aplanatic system.
Applications
The improved design of the solar concentrator is applicable to concentrating photovoltaic systems, and is particularly suitable for concentrating photovoltaic systems with multi-junction solar cells.
Advantages
The design with a Köhler homogenizer for aplantic solar concentrators offers advantages including:
• uniform irradiance distribution;
• small and simple lens element; and
• no need to glue the cell.
Inventors
Roland Winston
Weiya Zhang
