Posted by BobG on October 12, 2005, 9:42 pm
I'm trying to figure out if rewiring a 12v panel to 2.7v to charge one
of those 2600 Farad Maxwell Boostcaps would gain anything. The
individual cells are about .44v and a couple amps. 5 or 6 in series
would just match up to a 2.7v boostcap. Then a custom dc to dc
converter that could sniff the boostcap from about .5 to 2.7v and pwm
the output to 14.4v or something useful. Good holdup during quick
flybys of clouds is the only advantage I can think of so far..... If
anyone else thinks this is a good idea because _______ please report
Posted by Anthony Matonak on October 13, 2005, 3:08 am
You might find it easier to just put 5 or 6 of those bootcaps in
series to match the voltages. Then again, it would be much cheaper
to simply use a 12V battery. If you are concerned about getting the
most energy into your batteries then a MPP (Maximum Power Point)
charge controller sounds like a better idea.
Posted by Eric Sears on October 12, 2005, 11:08 pm
Well you've had lots of comments - so I will just tell you what I've
About 4 or 5 years ago, when panels were about NZ$1- 13 a watt here
for the larger sizes (80w), I imported "blemished" and broken cells
from US at about NZ$.50 a watt (included postage, taxes etc). Most of
these were for a friend who ran his remote house on microhydro and
solar. He built about 10 X50 watts panels, costing about NZ$ a watt
when finished. These included aluminium frames, with standard glass
front and plastic back, sealed with silicone. He subsequently
subdivided his property, sold that house and built a new one, but as
far as I know the solar panels are still working fine.
It WAS a lot of work, but he said it was worthwhile and since he had
little employment at the time - it was a great help.
The solar cell company provided good information with the cells to
help with the process of soldering.
I still have about 300 watts of the cells here (to use on a holiday
home) - but have also since imported solar laminates which are
probably a better deal.
One advantage of making your own is that you can make "custom-size"
panels to some extent - eg square ones to fit inside a roof under
transluscent sheet for security where you only want a trickle charge.
Or lower voltage panels if you need them.
I was lucky enough to be given over 100 sheets of thin window glass,
about 16" x 20" - make good 4 volt or 6 volt panels.
Just my tuppence worth
Posted by ewitte on November 1, 2005, 2:05 pm
If your interested in a small experiment you can get about 2W out of a
$.39 transistor. Keep in mind though you HAVE to heavily concentrate
light onto it and heatsink. Because without that its closer to .0003
watts. With a cheap mag lens .03 watts. You need a good fresnal lens
to do any good. We have been testing with 2N3055 transistors.
Posted by Jeff Thies on November 3, 2005, 6:41 pm
How in the world do you do that? 2N3055 are not light sensitive in as
much as they are enclosed in either metal or plastic!