Aleksandra Cvetkovic, Optical Scientist with LPI-Europe, presented “Advanced PV Concentrators” at the 34th IEEE PV Specialist Conference (Philadelphia, June 7-12th 2009) The presentation was based on a portion of LPI’s recent work in concentration photovoltaics (CPV). The article contains an introduction to an optical concept that ensures both high concentration and high acceptance angle, while providing high efficiency and good irradiance uniformity on the solar cell. Three different solutions for PV concentrators were presented. The SMS3D XR design, as employed in the current Boeing HCPV project, exhibits superior performance in both acceptance angle and efficiency. A Fresnel concept, incorporating Köhler integration, offers 2.3x more acceptance angle and perfectly uniform cell illumination, when compared with a standard Fresnel lens designs, that leads to high irradiance peaks on a solar cell. A another design compares a standard two mirror+ integrating rod aplanatic design to a LPI Köhler design with two modified mirrors and a freeform lens instead of the integrating rod. While the acceptance angle and efficiency are kept the same, the concentration could be raised from 850 to 2000 suns. Click here for a copy of her presentation The LPI presentation was complemented with a presentation given by Adam Plesniak (The Boeing Company) titled by “High Performance Concentrating Photovoltaic Module Designs for Utility Scale Power Generation”. This presented the results of field measurements of the previously mentioned XR SMS3D design including a 29.4% of module electrical efficiency.