Dish-based high concentration PV system with Köhler optics

Area of Science:

• Renewable Energy
• Optical Engineering
• Photovoltaics

Background:

• High concentration photovoltaic (HCPV) systems are crucial for efficient solar energy conversion.
• Traditional HCPV designs face challenges in uniform illumination and optical loss.

Purpose of the Study:

• To develop and evaluate a novel XRX-Köhler optical system for HCPV applications.
• To achieve high optical efficiency and uniform light distribution for triple-junction solar cells.

Main Methods:

• Designed an XRX-Köhler optical system with a large primary paraboloidal mirror and secondary reflectors.
• Constructed a prototype with a 3.3m x 3.3m primary reflector focusing light onto 36 actively cooled triple-junction cells.
• Measured system performance at 1200x geometric concentration.

Main Results:

• Achieved a measured end-to-end system conversion efficiency of 28%, including active cooling parasitic losses.
• Demonstrated uniform illumination and even light distribution across cells.
• Projected efficiency of ~32% for the next iteration of the system.

Conclusions:

• The developed XRX-Köhler optical system offers a robust and efficient solution for HCPV.
• The design methodology allows for generous tolerance to mis-pointing and efficient series connection of cells.
• This approach shows significant potential for advancing solar energy conversion efficiency.