As we all know, there are a lot of ways to harvest waste heat but the one that stands out in my mind is from a message posted about six months ago. I don't know if this is a solution, but I'm definitely curious to know one way or the other.
http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html
http://www.mail-archive.com/biofuel@sustainablelists.org/msg59540.html
1) Oils are generally non-conductive so, the PV cells can be immersed in it without shorting.
2.) Some oils can come with fairly good optical qualities - important for passing light to PV and transforming light to electricity.
Joe: I remember reading your post about experimenting with black bodies and it looks like you have a background that may be useful here. Maybe you can chime in (if your reading this thread)?
Mike
Zeke Yewdall <[EMAIL PROTECTED]> wrote:
This is basically what I did. kludging would be the word for it, as
about once a week it would have a catestrophic leak and I'd have to
rebuild it. Worked okay to get research data, but obviuosly not long
term.... I found that preheating water for domestic hot water (which
could have final heating done either by real solar thermal collectors,
or gas/electric/etc) seemed to be the best. Try to get it too hot and
the efficiency dropped way off (I had water tubes touching the back of
the PV module, but no front glazing), plus it didn't cool the PV cells
enough to help with electrical efficiency much either. The trick is
to size the storage tank and PV area with the daily draw to still get
the cooling effect and not stagnate the tank. I suppose with a
different collector design you could obtain higher temperatures, and
still probably not damage the PV module (unless the circulation loop
stagnated, then I'm not sure), but I was going more for cooling the
PV, and seeing the collected thermal energy could be useful, rather
than having high quality thermal energy as the primary goal. Given
that typical solar thermal DHW system here in the US don't achieve
100% solar fraction anyway, I figured that preheat was a decent way to
go. If you wanted to go for 100% solar fraction (which is what we
should be doing long term) cascading it with a higher temp solar
thermal collector might be alot better.
On 5/15/06, Chip Mefford <[EMAIL PROTECTED]>wrote:
> Zeke Yewdall wrote:
> > This is exactly what I did my master's thesis on. The concept works
> > pretty well from a theoretical perspective. I was just investigating
> > using water cooling for non-concrentrating PV, but it would work even
> > better for concentrating PV. You shouldn't really have to deal with
> > 1200F, at least if you are talking about water, because the maximum
> > working temp for a water based fluid is probably about 400F or so??
> > (assuming antifreeze additives and increased pressure). Depends on
> > how much pressure you are talking about I guess.
> >
>
> l was thinking of kludging up water jackets for PV panels, to feed
> the INFLOW for a small evacuated tube solar heater, preheating the
> inflow by 'cooling' the PVs.
>
> Do you think this makes sense?
_______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org
Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
