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Energy Express

Energy Express

  • Editor: Christian Seassal
  • Vol. 22, Iss. S2 — Mar. 10, 2014
  • pp: A211–A224

Dish-based high concentration PV system with Köhler optics

Blake M. Coughenour, Thomas Stalcup, Brian Wheelwright, Andrew Geary, Kimberly Hammer, and Roger Angel  »View Author Affiliations

Optics Express, Vol. 22, Issue S2, pp. A211-A224 (2014)

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We present work at the Steward Observatory Solar Lab on a high concentration photovoltaic system in which sunlight focused by a single large paraboloidal mirror powers many small triple-junction cells. The optical system is of the XRX-Köhler type, comprising the primary reflector (X) and a ball lens (R) at the focus that reimages the primary reflector onto an array of small reflectors (X) that apportion the light to the cells. We present a design methodology that provides generous tolerance to mis-pointing, uniform illumination across individual cells, minimal optical loss and even distribution between cells, for efficient series connection. An operational prototype has been constructed with a 3.3m x 3.3m square primary reflector of 2m focal length powering 36 actively cooled triple-junction cells at 1200x concentration (geometric). The measured end-to-end system conversion efficiency is 28%, including the parasitic loss of the active cooling system. Efficiency ~32% is projected for the next system.

© 2014 Optical Society of America

OCIS Codes
(220.1770) Optical design and fabrication : Concentrators
(350.6050) Other areas of optics : Solar energy
(080.2175) Geometric optics : Etendue
(220.2945) Optical design and fabrication : Illumination design
(080.4295) Geometric optics : Nonimaging optical systems

ToC Category:
Optical Design for Energy Applications

Original Manuscript: December 4, 2013
Revised Manuscript: January 10, 2014
Manuscript Accepted: January 13, 2014
Published: January 22, 2014

Virtual Issues
Renewable Energy and the Environment (2014) Optics Express

Blake M. Coughenour, Thomas Stalcup, Brian Wheelwright, Andrew Geary, Kimberly Hammer, and Roger Angel, "Dish-based high concentration PV system with Köhler optics," Opt. Express 22, A211-A224 (2014)

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