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From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: sci.energy,sci.electronics
Subject: Re: solar cells
Message-ID: <1991Jan5.225316.12934@cs.rochester.edu>
Date: 5 Jan 91 22:53:16 GMT
References: <1991Jan4.173128.26484@cs.rochester.edu> <1991Jan5.011526.15425@midway.uchicago.edu> <1991Jan5.025526.9284@cs.rochester.edu> <1991Jan5.222423.14844@bronze.ucs.indiana.edu>
Reply-To: dietz@cs.rochester.edu (Paul Dietz)
Organization: University of Rochester Computer Science Dept
Lines: 19

I wrote:
>>The ability to use diffuse sunlight is an advantage, but high
>>concentration is also nice -- silicon solar cells (at least) become
>>more efficient at high concentration ratios (at constant temperature).
>>I'm not sure why this is.  Also, concentration schemes should have

In article <1991Jan5.222423.14844@bronze.ucs.indiana.edu> amirza@silver.ucs.indiana.edu (anmar mirza) writes:

>It is actually very simple, more photons in=more electrons out. 

No, you misunderstand: I was talking about *efficiency*, not power
output.  The fraction of the light falling on the cell that is
converted to electrical energy is higher at high intensity, so actual
power output (at constant cell temperature) increases superlinearly
with concentration ratio (considering only direct sunlight).  I don't
understand why this is.

	Paul F. Dietz
	dietz@cs.rochester.edu