<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
<title></title>
</head>
<body bgcolor="#ffffff" text="#000000">
Allan,<br>
<br>
You could use the generator starting battery instead of a separate
battery and PV charger. But either way a very small PV module (not the
one used to charge the battery) could be used as a light sensor input
signal for a Morningstar relay driver that starts the generator and
changes the power supply from pv to ac. The hard part may be locating
suitable relays. With a 100K buffer tank, exactness on the timing of
the switchover shouldn't be necessary.<br>
<br>
Kent Osterberg<br>
Blue Mountain Solar<br>
<br>
<br>
<br>
<br>
Allan Sindelar wrote:
<blockquote cite="mid:4E139E15.90900@positiveenergysolar.com"
type="cite">
<meta http-equiv="content-type" content="text/html; ">
Wrenches,<br>
A good client of ours is a rancher in the New Mexico/Arizona border
area. He has a specific need for which I couldn't offer a simple system.<br>
<br>
He needs to raise water from a lake 400+/- vertical feet to a 100K
gallon storage tank for agricultural use. The site is remote. The
amount is substantial - about 10-12 gpm continuously, 24/7. He would
like to use 4 Grundfos SQ Flex pumps at about 2.5-3 gpm, each running
array-direct feeding a common pipe to the tank. He then wants to use
about an 8kW (derated to 6kW for 7,500' elevation) diesel generator
(with standard two-wire automatic start) to run all four pumps when the
sun goes down, and shut off and transfer back to PV when the sun comes
up the next morning.<br>
<br>
How might this be done? If we assume that each pump has four 210W
modules, that would be an 80Vnom array with MPP around 120V and Voc
around 150V. I would assume that both of these voltages are too high to
use any stand-alone AGS, such as Atkinson or Magnum. We considered a
separate tiny 12V or 24V battery with small PV module, used just to
power an AGS voltage sense signal, with the voltage difference between
float (13.6V) and rest (12.7V) triggering a voltage-actuated start
signal, but rejected this as problematic as battery temperatures
affected charge voltages. A self-contained time switch, such as some of
the newer Intermatic units, might work, if the right model can be
identified and isn't a substantial phantom load.<br>
<br>
We would also have to adapt a relay to switch between sources, with a
120 or 240 V AC relay coil current, energized by the generator. The
Grundfos IO101 AC interface unit is manual only.<br>
<br>
Has anyone solved this problem? Any ideas for a reasonably simple and
trouble-free approach would be welcome.<br>
Thank you,<br>
Allan<br>
<br>
<div class="moz-signature">-- <br>
<meta http-equiv="content-type"
content="text/html;
charset=ISO-8859-1">
<title></title>
<font face="Times New Roman, Times, serif"><b>Allan Sindelar</b></font><br>
<small><a moz-do-not-send="true"
href="mailto:Allan@positiveenergysolar.com"><font color="#000099"
face="Times New Roman, Times, serif"><u>Allan@positiveenergysolar.com</u></font></a></small><font
face="Times New Roman, Times, serif"><br>
<span style="font-size: 10pt;">NABCEP Certified Photovoltaic Installer<br>
NABCEP Certified Technical Sales Professional<br>
New Mexico EE98J Journeyman Electrician<br>
<b>Positive Energy, Inc.</b><br>
3201 Calle Marie<br>
Santa Fe, New Mexico 87507<br>
<b>505 424-1112</b><br>
<a moz-do-not-send="true" href="http://www.positiveenergysolar.com/"
target="_blank"><u>www.positiveenergysolar.com</u></a><o:p></o:p></span></font>
<p class="MsoNormal" style="margin-right: 722.25pt;"><span
style="font-size: 10pt;"><font
face="Times New Roman, Times,
serif"><st1:place w:st="on"><st1:city
w:st="on"></st1:city><st1:state w:st="on"></st1:state><st1:postalcode
w:st="on"></st1:postalcode></st1:place></font><b style=""><br>
</b></span></p>
<span style="font-size: 10pt;"><br>
</span> </div>
<pre wrap="">
<hr size="4" width="90%">
_______________________________________________
List sponsored by Home Power magazine
List Address: <a class="moz-txt-link-abbreviated" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a>
Options & settings:
<a class="moz-txt-link-freetext" href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a>
List-Archive: <a class="moz-txt-link-freetext" href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a>
List rules & etiquette:
<a class="moz-txt-link-abbreviated" href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a>
Check out participant bios:
<a class="moz-txt-link-abbreviated" href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a>
</pre>
</blockquote>
</body>
</html>