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re: home solar system cost??
20 jul 2005
san francisco wrote:
>>>the payback for several thousands of dollars at a dollar or less per
>>>day is over 10 years no matter how many times i tweak the spreadsheet.
>>>it aint a money makin investment.
>>
>> sounds like you are talking about pvs vs sunspaces for house heating,
>> which can be 100x cheaper per peak watt. i'll be giving a talk to that
>> effect and pe drew gillett and phd rich komp and i will be giving
>> a workshop on "solar heating and natural cooling" aka "ohm's law for
>> heatflow" at the pa renewable energy festival on 9/24/05 in kempton, pa,
>> 15 miles west of allentown and 10 miles north of reading. see
http://www.paenergyfest.com
>this is very misleading and erroneous
a 4-year layer of poly film costs 5 cents per square foot and collects
about 225 btu/h-ft^2 (66 w/ft^2.) that's $0.05/66 = $0.00076 per peak
watt... $4/$0.00076 = 5275 times cheaper than $4/pw pvs.
>sun spaces can help some in winter, but they also hurt to a degree in
>summer, an overall gain due to overhangs, but a slight one
a sunspace can help a lot in wintertime. ever heard of the barra system?
>and giving figures like "100x cheaper" makes you look ridiculous and silly
it might be more accurate to say "5275x cheaper" :-)
>the only solutions that have shown much promise of any great savings are
>some of the interactive ones, such as a computer controlled roof that
>changes it's color from black to white with the seasons.
i disagree. ever heard of john hait, norman saunders, harry thomason, or
john christopher (and his 98% solar-heated csi building in new hampshire)?
>but no combination of design technologies can make your power bill 100x
>cheaper, or even 10x cheaper
a large wire loop under a power line might help.
>you don't help our green cause by spouting silliness
you might enjoy our workshop.
nick
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