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.
Cheers, Jay Nunatak AES On Fri, May 7, 2010 at 7:59 AM, <hol...@sbcglobal.net> wrote: > 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..... > Holt E. Kelly > Holtek Fireplace & Solar Products > 500 Jewell Dr. > Waco TX. 76712 > 254-751-9111 > www.holteksolar.com > > ----- Original Message ----- > *From:* Allan Sindelar <al...@positiveenergysolar.com> > *To:* RE-wrenches <re-wrenches@lists.re-wrenches.org> > *Sent:* Thursday, May 06, 2010 11:50 PM > *Subject:* Re: [RE-wrenches] Load size for off-grid lodge > > Jason, > 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. > > We never did the project, as they decided to go with dual generators. We > did get compensated for extensive design work. > > 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. > > Here's what I wrote in the initial pre-proposal: > > <!--[if !supportLists]-->*I. *<!--[endif]-->*Load > Profile Methodology and Limitations* > > 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. > > 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. > > > From this *we have estimated that XX Lodge may be expected to have a total > average daily load not exceeding 190 kilowatt-hours per day*, 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. > > 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. > > Hope this little bit helps. > > <![endif]--> > > *Allan** Sindelar* > al...@positiveenergysolar.com > NABCEP Certified Photovoltaic Installer > EE98J Journeyman Electrician > *Positive Energy, Inc.* > 3201 Calle Marie > Santa Fe, New Mexico 87507 > *505 424-1112* > www.positiveenergysolar.com > > > jason pozner wrote: > > Hey all, > > 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. > > 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? > > Thanks > Jay Pozner > Nunatak Alternative Energy Solutions > > > > ------------------------------ > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & > settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette:www.re-wrenches.org/etiquette.htm > > Check out participant bios:www.members.re-wrenches.org > > ------------------------------ > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > >
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