[VAC] Re: Solar panels mounting on roof

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

Jim,
 I don't remember his name, but I can tell you where his booth has been
the last 2 years:

As you enter the flea market area from the shuttle bus load/unload area,
you'll go to about the second aisle and turn Left. He's down just a few
booths. It might be the 3rd aisle, I'm not sure, but it's quite close to
where you come in.

Strong hint: if you buy from him, have him put a sticker on your "sold"
panel(s) and LEAVE THEM THERE until the end of the day. In 1999, I made
the mistake of loading the panel on my 'hamfest cart' and pushing it
around all day. If I'd had a buck for everyone who stopped me for
questions, I'd have paid for it:

1. "Where'd you get that panel?"
2. "How much did you pay?"
3. "How much output is it?"
4. "All ready for Y2K, huh? Heh, heh"

He has panels that are all mounted in frames with junction boxes on the
back, ready to mount. He has others, quite a bit cheaper, that have no
frames or boxes, but there will be considerably more work to put them to
use. He's very willing to connect a volt/ammeter to demonstrate their
function, and I've had no trouble at all with mine. IIRC, they were
$225.00/each. He has smaller panels (mine are 75-watt, about 21" X 48")
and some 100-watt panels.

Again, depending on what you want to do, you might need more panels than
you think. People who are very serious about never needing to connect to
shore power and want to run everything just as if they were, will
typically need at least 4, 75-watt panels with appropiate controller and
4 golf-cart batteries. They'll use an inverter of 600-1500 watt size for
the AC appliances, but still cannot run an A/C.

For those who think they can run an A/C unit from a battery bank,
consider this:

An A/C that draws 10 amps from the 120VAC line will draw over 100 amps
from a 12VDC battery bank. Straight calculations show that 4 golf cart
batteries are rated at 400 Amp-Hours, so should run the A/C for 4 hours.
However, that AH rating assumes a current draw that uses all that power
over 20 hours' time, or 20 amps max. If you pull 100 amps from the
battery bank, it'll last only a fraction as long, probably not much more
than an hour. Consider also that the heavy current draw will shorten the
life of the batteries, plus you don't want to use much more than 50% of
the battery's capacity on a routine basis, and you can see that we're
down to maybe a half-hour of A/C use.

On the other end, 4, 75-watt panels can be expected to provide less than
100 AH per day, so it'll take at least a couple of days to recharge
after using that A/C for less than an hour.

Lemme know how you make out!!

                                            <<Jim>>