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<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>Jay:</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>There are four systems in question. In three
the loads are year round and one is summer only AC loads.
</FONT></SPAN><SPAN class=023063719-16082013><FONT color=#0000ff size=4
face=Arial>The year round loaded systems have loads day and
night.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>One is a highway maintenence station with at least 4
residences.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>One is a family compound with two homes with electric ranges,
water heaters, AC units (I know its stupid, lord knows I've tried to convince
them to change appliances.)</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>One is an animal rescue operation with heater
loads.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>One is a large home with 5 very small, very new, very
sophisticated and frugal AC units</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>I know it is silly to move these loads off-grid, but people do
it and they will hire someone to work on the systems. It may as well be
me, doing the best I can to use the resources as wisely as
possible.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>William</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>PS: It always happens like this: I get a call from
a client with problems. Well, of course their expensive battery bank
died and it died because of wasteful appliances. The prescription is a
new, expensive battery bank and, at the same time, new, expensive,
efficient appliances. They complain can't afford both and they have
to have the batteries, so that is what they get. Repeat every two
years. Sad....</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial>Wm</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT color=#0000ff
size=4 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>Jay
Peltz<BR><B>Sent:</B> Friday, August 16, 2013 12:22 PM<BR><B>To:</B>
RE-wrenches<BR><B>Subject:</B> Re: [RE-wrenches] PV Assist<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV>Hi William</DIV>
<DIV><BR></DIV>
<DIV>I feel it's impossible to discuss without more specifics. </DIV>
<DIV><BR></DIV>
<DIV>For example if the extreme loads are only every ( just run the genny) so
often vs seasonal ( maybe AC coupling makes more sense vs cycling a extremely
expensive battery 4 x day), vs year round vs what is do able etc</DIV>
<DIV><BR></DIV>
<DIV>I would be curious to know what some of the parameters are, as I'm sure
others as well</DIV>
<DIV><BR></DIV>
<DIV>Jay</DIV>
<DIV><BR></DIV>
<DIV>Peltz power. </DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV><BR><BR>Sent from my iPhone</DIV>
<DIV><BR>On Aug 16, 2013, at 10:53 AM, "William Miller" <<A
href="mailto:william@millersolar.com">william@millersolar.com</A>>
wrote:<BR><BR></DIV>
<BLOCKQUOTE type="cite">
<DIV>
<META name=GENERATOR content="MSHTML 8.00.6001.23515">
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial>Friends:</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4 face=Arial>We have been
receiving a flurry of requests for design of off-grid systems where the loads
are enormous, relative to normal off-grid requirements. It is obvious
that the size of PV and battery arrays to power these loads is beyond
what is practical. We have dubbed these systems Generator/battery with
PV assist, or PV assist for short.</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4 face=Arial>These systems will
cycle batteries multiple times per day. It is my understanding that the
extra battery cycels will shorten battery life. Since generator run is
expected, we are willing to increase generator run time in order to prolong
battery life.</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4 face=Arial>The parameters I
suggest are an aggressive load start and a very high battery start
parameter. This will prevent deep discharge of the battery bank. I
know shallow discharge is not the norm, but I don't believe shallow cycling is
a problem as long is it as at the top of the voltage window, i.e. the
batteries achieve absorption at least once per day.</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4 face=Arial>We know a load
start ciuld result in an abbreviated run time, curtailing absorption
period, but we are assuming there will be a battery votage start at least once
per day allowing full absorption.</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4 face=Arial>Has anyone else
considered these issues, and what conclusions did you make</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4 face=Arial>I am looking
forward to a spirited discussion as usual. I throuroughlyenjoy and
beneift from them, even thought the advice is usually conflilcting.
Thanks in advance.</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4 face=Arial>William
Miller</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT size=4
face=Arial></FONT></SPAN> </DIV></DIV></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
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