Thanks all for the good suggestions on and off-list. We are going to go with a monitoring program. There were just too many variables to even try to guess with this project.<br><br>Cheers,<br>Jay<br>Nunatak AES<br><br><div class="gmail_quote">
On Fri, May 7, 2010 at 7:59 AM, <span dir="ltr"><<a href="mailto:holtek@sbcglobal.net">holtek@sbcglobal.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div text="#000000" bgcolor="#ffffff">
<div>As a bit of a swerve off the path of this string....I am designing a
grid-tie system for a building that is being "greenovated". Trying to lock down
a LEED req'd percentage shaving of annual demand. I know there is a place
to find assumptions from DOE, but I'm not that confident in those because they
can't possibly plug in all factors. Any sources out there that might drill down
the numbers a bit better? Or do I keep trying to hit the swinging dart board
blindfolded? EPRI seems to be designed for utilities, grid EE's and
such - haven't found any pertinent load assumption info on
the website..... </div>
<div>Holt E. Kelly<br>Holtek Fireplace & Solar Products<br>500 Jewell
Dr.<br>Waco TX. 76712<br>254-751-9111<br><a href="http://www.holteksolar.com" target="_blank">www.holteksolar.com</a><br></div>
<blockquote style="padding-right: 0px; padding-left: 5px; margin-left: 5px; border-left: 2px solid rgb(0, 0, 0); margin-right: 0px;"><div class="im">
<div style="font: 10pt arial;">----- Original Message ----- </div>
<div style="background: none repeat scroll 0% 0% rgb(228, 228, 228); font: 10pt arial;"><b>From:</b>
<a title="allan@positiveenergysolar.com" href="mailto:allan@positiveenergysolar.com" target="_blank">Allan Sindelar</a> </div>
<div style="font: 10pt arial;"><b>To:</b> <a title="re-wrenches@lists.re-wrenches.org" href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches</a> </div>
<div style="font: 10pt arial;"><b>Sent:</b> Thursday, May 06, 2010 11:50
PM</div>
<div style="font: 10pt arial;"><b>Subject:</b> Re: [RE-wrenches] Load size for
off-grid lodge</div>
<div><br></div>Jason,<br>We attempted this about 2-3 years ago for a project
on one of Ted Turner's ranches. This was to be a top-of-the-line eco-lodge at
10,000' below a ridge in the northern Rockies in New Mexico, with two 7kW
Provens and a 3-phase Sunny Boy/Sunny Island system. Due to the lack of real
load analysis, and the need to have large but essentially unknown capacity at
the lodge, the initial estimate was about $900K, as I recall. <br><br>We never
did the project, as they decided to go with dual generators. We did get
compensated for extensive design work.<br><br>You may need to focus on large
efficiencies and then put a usage fraction, like 60%, on the electrical
engineer's traditional load calcs. That's what we did. And write in a section
stating that you make no warranties as to the sufficiency of the system to
meet actual loads, as the loads can't be accurately determined.
<br><br>Here's what I wrote in the initial pre-proposal:<br>
</div><blockquote>
<p class="MsoNormal" style="margin-left: 0.5in;"><!--[if
!supportLists]--><b><i><span style="font-family: Garamond;"><span>I.<span style="font: 7pt 'Times New Roman';">
</span></span></span></i></b><!--[endif]--><b><i><span style="font-family: Garamond;">Load Profile Methodology and
Limitations</span></i></b></p><div class="im">
<p class="MsoNormal"><span style="font-family: Garamond;">Typical off-grid PV
systems are designed and sized based on a rigorous load analysis as an
essential first step. The load analysis is a detailed listing of every
electricity-consuming device, with power consumption and expected daily
usage figures, used to develop an accurate profile of total expected daily
kilowatt-hour consumption. From this data a power system of specific design
and capacity is developed.</span></p>
<p class="MsoNormal"><span style="font-family: Garamond;"></span></p>
<p class="MsoNormal"><span style="font-family: Garamond;">This approach is not
possible for the XX Lodge, so an alternative approach must be used to
establish target design criteria. EPRI (Electric Power Research Institute,
the research arm of the U.S. electric utility industry)
has developed Technology Assessment Guides to predict power use for various
residential and commercial sectors. The comparative sector of lodging at
12,000 square feet in the western U.S., establishes a figure of 223
kilowatt-hours per day. This is a base figure, for conventional design
without energy-conserving measures, with adders for electric heat, hot
water, cooking and air conditioning, none of which will be used at XX Lodge.
</span></p>
<p class="MsoNormal"><span style="font-family: Garamond;"></span></p>
<p class="MsoNormal"><span style="font-family: Garamond;">From this <b>we have
estimated that XX Lodge may be expected to have a total average daily load
not exceeding 190 kilowatt-hours per day</b>, or 85% of the EPRI figure.
This is the figure used in this preliminary budget analysis. This may be
considered to be quite conservative; that is, careful attention to
energy-conserving approaches during design and construction are likely to
considerably reduce this figure.<br></span></p></div></blockquote><div class="im">
<p class="MsoNormal">Remember too that if they now have generators, they're not
likely to conserve, as generator power is pretty much all-or-nothing, with
efficiency unimportant within the gennie capacity. So there's a fair amount of
load management and education to fit in.<br></p>
<p class="MsoNormal">Hope this little bit helps.<br><br></p>
<blockquote>
<p class="MsoNormal"><span style="font-family: Garamond;"></span></p></blockquote>
</div><div>
<![endif]-->
<div><div></div><div class="h5">
<div>
<p class="MsoNormal"><span><b>Allan</b></span><b> Sindelar</b><span style="font-size: 10pt;"><br><a href="mailto:Allan@positiveenergysolar.com" target="_blank"><span>Allan</span>@positiveenergysolar.com</a><br>NABCEP Certified
Photovoltaic Installer<br>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 href="http://www.positiveenergysolar.com/" target="_blank">www.positiveenergysolar.com</a></span></p></div></div></div></div><div><div></div><div class="h5"><br><br>jason
pozner wrote:
<blockquote type="cite">Hey all,<br><br>I am trying to size a PV/generator system for a
10,000 ft2 off-grid hunting/snowmobile lodge with outbuildings. The
goal is to significantly reduce current generator run time. I was
wondering if any of you have experience or suggestions for calculating time
of use of lights, etc in a lodging situation. My interviews with the
rancher have proven fruitless to pin down any time of use of most loads,
though I do have an estimated run time for the genny in summer and
winter. I did get a pretty good snapshot of his connected load by
turning on all I could on and clamping the feeds. <br><br>The lodge is
18 rooms, 4 for the help, and a few outbuildings. Has anyone sized any
off-grid lodges? Any other ways to approach the moving target of
such a fluctuating load at a guest lodge? <br><br>Thanks<br>Jay
Pozner<br>Nunatak Alternative Energy Solutions<br><br><br><br><pre><hr size="4" width="90%">
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