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<DIV>I suppose it would be an interesting exercise to do the math but my
experience with very cold groundwater input to a gas on-demand heater (Aquastar)
showed very efficient fuel usage even with the cold water input. It
seems that trying to heat a tank of that cold water with PV, especially if they
are using water during the day and thus always adding cold water to the tank,
would be an exercise in futility and a waste of good PV.</DIV>
<DIV> </DIV>
<DIV>Tom</DIV>
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<DIV style="font-color: black"><B>From:</B> <A title=sgsrenewables@gmail.com
href="mailto:sgsrenewables@gmail.com">Luke Christy</A> </DIV>
<DIV><B>Sent:</B> Monday, May 13, 2013 4:59 PM</DIV>
<DIV><B>To:</B> <A title=re-wrenches@lists.re-wrenches.org
href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</A>
</DIV>
<DIV><B>Subject:</B> [RE-wrenches] PV-direct electric water
heating</DIV></DIV></DIV>
<DIV> </DIV></DIV>
<DIV
style="FONT-SIZE: small; FONT-FAMILY: 'Calibri'; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; TEXT-DECORATION: none; DISPLAY: inline">Hi
Wrenches,
<DIV>Now that the cost of modules has come down so much, has anyone out there
experimented with solar <I>electric </I>water<I> </I>heating? As in: direct
connecting a short series string of PV modules to a tank -style electric water
heater with an element of an appropriate voltage and wattage rating…?</DIV>
<DIV> </DIV>
<DIV>A off-grid customer of mine who is also an electrical engineer has a
situation that seems ideal for trying this idea out: he has a gas-fired tankless
water heater and a water source that is very cold year-round. The idea is to
take a 30 or 40 gal electric tank heater, switch out one of the the 240V
elements to something like a 96VDC, 1000W element (difficult to find, but
available), and direct connect 3 or 4 60-cell modules in series (with a
disconnect and high-limit control of course). The tank would then serve to
preheat the cold feed to the tankless heater. We think we can get a decent daily
temperature rise with this setup. Probably not enough to heat the tank to a
normal DHW temperature, but certainly enough to offset a good deal of propane
consumption, and all for what I predict will be considerably less cost than a
small solar thermal system.</DIV>
<DIV> </DIV>
<DIV>Has anyone tried this? I'd appreciate any insights or opinions.</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>Thanks</DIV>
<DIV>
<DIV>
<DIV apple-content-edited="true">-Luke Christy</DIV>
<DIV apple-content-edited="true"><BR>NABCEP Certified PV Installation
Professional™: Certification #031409-25 <BR>NABCEP Certified Solar Heating
Installer™: Certification #ST032611-03
<BR>CoSEIA Certified PV Installer <BR><BR>Solar Gain Services, LLC<BR>PO Box
531<BR>Monte Vista, CO. 81144<BR><A
href="mailto:SGSRenewables@Gmail.com">SGSRenewables@Gmail.com</A><BR>719.588.3044<BR>www.sgsrenewables.com<BR><BR>
<BR><BR><BR><BR><BR><BR><BR></DIV>
<DIV> </DIV></DIV></DIV>
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