Hybrid Car – More Fun with Less Gas

Newbie here - wants to do diy solar - needs help please! - Page 3

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Posted by nicksanspam on November 30, 2008, 12:45 pm
 


Solar heat from a sunspace can be 100 times cheaper than PVs per peak watt,
and houses need several times more heat than electrical energy.
 

$00 might buy 200 ft^2 of "solar siding," eg a thermosyphoning air heater
with 4 12'x4' pieces of R2 Thermaglas Plus twinwall polycarbonate with 80%
solar transmission. In full sun (250 Btu/h-ft^2) on a 30 F day, you might
collect 200 Btu/h-ft^2 of 150 F air and lose (150-30)1ft^2/R2 = 60, ie 140
net (41 watts), at $/41 = $.073 per peak watt. The 7.9 kW output could
heat a house and water for showers, with the help of a $5 car radiator and
its 12 V 20 watt fans and a $0 13-gallon 1`x300' pressurized plastic pipe
coil in a polywood tank with a folded EPDM liner.


Ohm's law for heatflow is just Ohm's law for electricity with different units.

Nick


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