Maximally concentrating optics for photovoltaic solar energy conversion

Technical Report · Thu Mar 07 00:00:00 EST 1985

DOI:https://doi.org/10.2172/6936263· OSTI ID:6936263

O'Gallagher, J J

Use of a two-stage concentrator with a fresnel lens primary and a nonimaging dielectric totally internally reflecting secondary, has unique advantages for photovoltaic concentration. Some preliminary ray trace studies have shown that with planar lenses, an increase in angular acceptance for a given geometric concentration to about 2/3 of the maximum theoretical limit can be achieved. To demonstrate this, two preprototype concentrators, each having a geometric concentration of 248:1 for a 0.635cm (0.25 inch) diameter cell, have been designed, built, and tested. Measurements of the angular response show an acceptance of 8[degrees] (full angle) which is drastically better than the 1[degrees]--2[degrees] achievable without a secondary, and is in excellent agreement with the ray trace predictions. For these preprototypes, passive cooling was sufficient to prevent any thermal problems for both the cell and secondary. No problems associated with nouuniform cell illumination were found, as evidenced by the fill factor of 71%--73% measured under concentration. Initial measurements of the system electrical efficiency lie in the range 7.5%--9.9% for a variety of individual cells.

• Research Organization: Chicago Univ., IL (United States). Enrico Fermi Inst.
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-84CH10201
• OSTI ID: 6936263
• Report Number(s): DOE/CH/10201-T3; ON: DE93002846
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
CONCENTRATOR SOLAR CELLS
DESIGN
OPTICAL SYSTEMS
COOLING
EFFICIENCY
FILL FACTORS
FRESNEL LENS
LENSES
PROGRESS REPORT
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
EQUIPMENT
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SOLAR CELLS
SOLAR EQUIPMENT
140501* - Solar Energy Conversion- Photovoltaic Conversion