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<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>Hi
William, </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>I have
done many systems in identical situations & share your philosophy.
Remote communities, work camps, highway maintenance compounds, etc...
</FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013></SPAN><SPAN class=494595322-16082013><FONT
face=Arial color=#0000ff size=2>I have used two general philosophies on
batteries for these systems. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>1.
Cheap batteries, ie L16's. Cycle them hard and realize they will be dead in
18-24 months. Keeping them cool is the biggest challenge with multiple cycles a
day. Special attention to air flow in battery box helps. One site was able
to config the room so the cold air intake for generator passes through the
battery bank. Worked quite well. Also good for billable hrs to be replacing
batteries constantly. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN><SPAN class=494595322-16082013><FONT face=Arial
color=#0000ff size=2></FONT></SPAN><SPAN class=494595322-16082013><FONT
face=Arial color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>2.
Higher quality flat plate 2V cells. Spend more now, shallow cycle them to around
60-70% DOD, have the gens set to kick in based on high continual AC demand (and
shut down when that load abates). </FONT></SPAN><SPAN
class=494595322-16082013><FONT face=Arial color=#0000ff size=2>Generally
speaking the threshold for that is 50% of the inverter rating but each site is
unique. Some sites I have the gen may kick in up to 6x a day, not full cycles.
Some sites with predictable peaks ie camps have timers to run gen from
6-8am then 5-7pm, to coincide with meals. Though I prefer based on AC demand.
More flexible to adapt to the conditions ie if the site is shut down.
</FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>For
either config, a single point battery watering system is ideal, as uses a lot of
water. Can be automated so the filling system pump runs for xx seconds at the
start of each absorb cycle. I've had to go through a lot of junk & few
dry cells to find one system that does this reliably. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2>Pricing wise over 10 years generally works out about the same, but
cash flow is easier for cheap batteries, they just know they will have to
spend a couple grand a year on batteries. They are saving 10's of thousands in
diesel so still works out economically. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2>Generally speaking, inverter capacity is 50% of generator. Several 50 kW
diesel / 30 kW inverter / 100 kWh battery systems out there. A larger system we
put in 16 months ago uses 100 kW diesels, 60 kW inverter, 400 kWh battery
storage. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>I've
worked with every inverter out there, and the SMA Sunny Island does the best job
of properly charging batteries / and keeping generator runtime as low as
possible. It can be set to short-charge batteries most of the time, ie shortened
absorb stage and then every x cycles (defined) it will do a full charge. Find
that is the very best balance between fuel use / battery life.
</FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>Solar
PV (or other renewables) are easy add ons. Every kWh from renewables is
saving diesel. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>Hope
that is useful. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013></SPAN><SPAN class=494595322-16082013><FONT
face=Arial color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>Kevin
Pegg</FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff size=2>EA
Energy Alternatives Ltd. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2>British Columbia, Canada. </FONT></SPAN></DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=494595322-16082013><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org]<B>On Behalf Of </B>William
Miller<BR><B>Sent:</B> August 16, 2013 12:49 PM<BR><B>To:</B>
'RE-wrenches'<BR><B>Subject:</B> Re: [RE-wrenches] PV
Assist<BR><BR></FONT></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>Jay:</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>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 face=Arial
color=#0000ff size=4>The year round loaded systems have loads day and
night.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>One is a highway maintenence station with at least 4
residences.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>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 face=Arial
color=#0000ff size=4>One is an animal rescue operation with heater
loads.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>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 face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>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 face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>William</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>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 face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4>Wm</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=023063719-16082013><FONT face=Arial
color=#0000ff size=4></FONT></SPAN> </DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><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 content="MSHTML 8.00.6001.23515" name=GENERATOR>
<DIV><SPAN class=353174017-16082013><FONT face=Arial
size=4>Friends:</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial
size=4></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial size=4>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 face=Arial
size=4></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial size=4>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 face=Arial
size=4></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial size=4>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 face=Arial
size=4></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial size=4>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 face=Arial
size=4></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial size=4>Has anyone else
considered these issues, and what conclusions did you
make</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial
size=4></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial size=4>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 face=Arial
size=4></FONT></SPAN> </DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial size=4>William
Miller</FONT></SPAN></DIV>
<DIV><SPAN class=353174017-16082013><FONT face=Arial
size=4></FONT></SPAN> </DIV></DIV></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
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