Anyone out there have evacuated tube Solar? How is it working out?

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Seasoned Oak

Minister of Fire
Oct 17, 2008
7,215
Eastern Central PA
Im curious to know how evacuated tube is working for those who took that leap. Is it keeping up? Worth the dough? Would you do it again ?
 
I haven't tried it, but I'm convinced its the way to go if you want hot water in cold weather. Problem is the rebates only apply to the expensive panels. I see a deal on panels and they're not listed/rated for the rebate, so you can't get the subsidy. Big surprise: The larger, more expensive companies who lobby Washington have developed a system to keep their panels competitive with foreign companies. I guess I could make some panels for the hosue but the glazing would be very expensive, and I like the idea of being able to change a single tube if something were to hit the panel instead of having 10 sqft of shattered glass. Polycarbonate is an option, but even more expensive.

By the time I add up the copper, wood, metal and glass I'm right around 200/panel, and I'd need almost twice as many to get to the eff. of a good evacuated tube model. I don't buy the U-tube videos. One guy had black pipe tyraped to his fence, and was all excited about 2 degree rise which came to about 100btu/hr.
 
btuser said:
By the time I add up the copper, wood, metal and glass I'm right around 200/panel, and I'd need almost twice as many to get to the eff. of a good evacuated tube model..

Here's a link to a local water solar installation near me with a side by side comparison of an evac tube setup and a flat plate setup.

http://chuck-wright.com/logger/tabs.php?loggerids[]=485E700680A6C389&tab=0

See his "generation" link. The flat plates are consistently out performing the tubes, so I don't think your 2 to 1 estimation is valid (though it does look like his flat plate collector has a little more sq footage). I'm not saying that a home made flat plate panel would put out what these commercial panels do, though. Just saying that the difference between evac, tubes and flat plate collectors might not be as much as we are led to believe. I also know another person that swears by his 80 (or more) tube evacuated tube arrays that heat his house. He claims they work better than anything else especially when the conditions are marginal (ie, mostly overcast). He's an engineer and should know, but I've heard from one other solar installer that there isn't a huge difference between evacuated tubes and a good flat plate collector.

Note: not sure why I can't get the above link to show up properly as a link. You'll have to copy and paste it into your browser.
 
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