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/ > > _______________________________________________ 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/
