|
|
re: was sizing
1 apr 2000
george ghio wrote:
>...if your inverter requires 25 amps per hour...
...your solar power consultant is really ignorant.
>...we are even told that it only takes 20 wh to heat 50
>pounds of lead to 25 degrees in an hour.
from 0 c. that is surprising, if one is ignorant. nobody mentioned hours
(which would have been a conceptual mistake), but the specific heat of
lead is 0.0309 btu/lb-f, right? so 50 pounds has a capacitance of 1.545
btu/f, so heating it 25 c, ie 45 f, takes 69.525 btu or 20.38 wh. people
have known this for hundreds of years, george.
>ya know this could be the biggest thing to hit solar power in years.
it might be helpful in cold climates in less ignorant hands, although
pvs and batteries are still very expensive. this technique was patented
in the 1940s. can you say "cargo cult"?
ignorance is curable, you know. arrogance less-so, and stupidity even
less ("yes madam, i'm drunk, but you are stupid, and i'll be sober
in the morning." --winston churchill.)
>so will a 20 watt light globe in the battery box really warm up our
>battery to 25 degrees c in one hour.
from 0 c? a resistor or strip heater under some insulation might work
better, with a better thermal attachment to the battery. this process
needn't happen that quickly, given the size of the battery bank and
the drain, over 5 days, and knowing the state of charge, with some
attempt at load prediction. warming the batteries over a day seems ok.
>or is it perhaps suggested that the lead plates be subjected to a
>dead short to heat them.
nope. that doesn't sound like a good idea, and nobody suggested that.
are you a bad reader, george, or merely enjoy making up straw men and
attributing them to others? one might heat batteries using their own
resistance, with alternate charging and discharging. that was also
patented long ago. but resistors are cheap and wear out batteries less.
>and what voltage will these watts be delivered at?
say 1 watt per battery, at 24 vdc, for a 24 v system.
>i have full accreditation for the design and installation with the
>solar energy industries australia
ghastly thought. are you all barking, then?
>i no longer have the time to debate with the nicks in this group.
embarrassing, isn't it? :-) you can always go back to welding...
>solar power is free. the equipment needed to use this free power is not
>free.
doh. we await further pearls of wisdom...
nick
|
|
