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Solar
Energy Concentrators
Description
Sunlight incident on broadband Holographic Optical Elements
(HOEs) can be focused and concentrated on solar cells to improve
overall system efficiency. Some general considerations
are:
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Photovoltaic
cells are less efficient as their temperature increases.
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Photovoltaic
cells are very inefficient across the wide bandwidth of
sunlight. UV light generates power but very inefficiently.
Red and near IR light generate useful electrons in the
conduction band because they have photon energies slightly
greater than the bandgap in silicon cells. Blue/Green
light produces useful electrons in the conduction band
because they have photon energies slightly greater than
the bandgap for gallium arsenide cells. IR light
produces heat that lowers the energy conversion at other
wavelengths.
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Concentrator
systems must be relatively large with minimum distances
between the optics and the photovoltaic cells.
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A well designed solar cell system using high
performance HOEs will provide all of the following advantages:
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Concentrate
light onto the appropriate photovoltaic cells
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Block
and/or diffract UV and IR away from these photovoltaic
cells
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Be
large enough with minimum geometry distances between optics
and photovoltaic cells
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Provide
high diffraction efficiencies across the usable light
bands
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Some solar cell systems with HOEs use Fresnel
lenses to concentrate light. Below is an example of
a system that does not use a Fresnel lens but incorporates
the focusing in the HOE. It is an advanced photovoltaic
system employing volume phase HOEs producing overall optical
efficiencies >30%. Concentrators as large as 1 square
meter can be made with our large dichromated gelatin film
coater.
We provide a high level of customer service.
Additionally, we offer consulting, design, prototype, product
integration, and quantity production at competitive prices.
For sales info call 435-752-4301 or email
us,
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