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From: jonk@netcom.com (Jonathan Dale Kirwan)
Subject: Re: Solar Insolation Levels
Message-ID: <jonkCuFu25.GBM@netcom.com>
Organization: New World Computing Services
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References: <ykgcqc4w165w@sfrsa.com> <af.6906.33.0NAF8FC6@mecheng.fullfeed.com> <Cu1v1p.JqB@armory.com> <Cu2Es6.I48@news.cis.umn.edu>
Date: Fri, 12 Aug 1994 19:56:28 GMT
Lines: 43

Brynn Rogers (roger034@gold.tc.umn.edu) wrote:
: In article <Cu1v1p.JqB@armory.com>,
: Richard Steven Walz <rstevew@armory.com> wrote:

: >Even in Death Valley, according to my passive solar technology instructor,
: >you cannot get over about 150 Watt's per meter squared at noon in the
: >summer on a clear day. I don't know why you think the atmosphere passes
: >that amount of flux so well. We'd all be par-boiled!! The reflectance is
: >much higher than that. I was instructed that orbit has, as a rule of thumb,
: >11 times more solar flux for conversion to heat, such as for smelting, etc.
: >We could melt steel in a pot with a 1' square Fresnel lens if that were
: >true, at its focus! We can only melt lead with a 1 footer.
: >
: >The 100 to 150 Watt figure was the one used very successfully to predict
: >the hot water ouput of all the old turn of the century hot water heaters on
: >roofs in Los Angeles and much of southern California till the natural gas
: >and petroleum got cheap!!! Few people know that the passive solar water
: >heater was well on its way to over 50% usage till cheap petrochemicals!
: >-Steve Walz 
: >

: This 150 W per square meter, is that what you can get out of the cells
: or what you think the total solar flux is?

: My source worked on Mankato States SunRaycer solar car and with the
: 8 square meter panel they would get 900W in bright sun, maybe even 
: 1000W occasionally.  Either their cells were way better than they
: paid for (%15 is what they had) or your number is what a solar cell
: can convert to power, NOT the total solar flux.

I wonder...  Is the apparent disagreement here simply a matter of 
confusion, instead?  rstevew argues that 150 watts/m^2 is in the ball 
park of reality.  roger argues that it is nearer 1000.  But notice that 
roger says they were using (8) meter^2 panels.  With that much area and 
with rstevew's figures they'd both be pretty close to an agreement.

So, does the 1000 watt figure come from a single meter^2, roger?  Or did 
their 8 meter^2 panels develop 1000 watts per meter^2, yielding about 
8000 watts for the whole panel?  Is there a disagreement or not?

Jon


