Maybe they could go “off-grid” with a cogeneration unit powered by biodiesel. That could make a lot of $ sense depending on their annual heating load and local kWh price. Our local biodiesel plant sells it cheaper then propane for now. Rough math is 1/3rd electricity, 1/3rd recoverable heat, and 1/3rd waste heat that you can’t get back. You could still take the some/most of the lighting, refrigeration and water pumping off grid with large but still standard set of battery based inverters, wind and solar.
Have you pointed out that batteries aren’t exactly environmentally friendly and reduce the efficiency of the system? That might trigger them to battery less grid tie. FYI, HUP now has a 1990 AH battery. Of course that’s still way too many stings to get to 19,000 AH (900+ kWh, wow) Speaking of big, high quality batteries; Special thanks to Jamie Surrette for helping me out last week. I was able to successfully weld a new terminal back on a Surrette 4v 1100 AH battery with his help. Best, Travis Creswell Ozark Energy Services _____ From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Allan Sindelar Sent: Monday, March 02, 2009 1:03 PM To: 'RE-wrenches' Subject: Re: [RE-wrenches] How large is too large? We had a similar lead come up a year ago, although the lodge in this case was 22 miles from mains power and 10K feet up. Thank goodness we had contracted $3500 in design fees up front to do all of the load projection and design research work. We determined that the batteries were the limiting factor: at 48V, about 2,000 amp-hours, and two or three strings max (depends on expected DOD), we couldn't provide a battery bank large enough. The only solution we arrived at was using Sunny Islands in 3 phase, redundant generators, duplicate services, Sunny Boys on arrays, and Windy Boys on two Provens to build an AC-coupled microgrid. That way we had duplicate battery banks. When we presented the general design approach to the owner's (common household name, largest private landowner in the US) representatives through the electrical engineer, with a preliminary estimate around $700K, they decided to run the lodge on generators. Allan Sindelar HYPERLINK "mailto:al...@positiveenergysolar.com"allan(at)positiveenergysolar.com NABCEP Certified Solar PV Installer Positive Energy, Inc. 3201 Calle Marie Santa Fe NM 87507 505 424-1112 -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Mark Dickson Hello Wrenches, I have a customer that has really likes the thought of being off-grid and they have asked me to design a system for their “lodge”. I have kicked and screamed to get them to consider a grid-tied system using their existing grid service—to no avail. After doing a preliminary load analysis, I have determined that it would take ~35kW of solar and a couple Bergey Excels for it to work along with a 19,000Ah battery bank. So, how big is too big? If we were to move forward on this, what would be the major obstacles/show stoppers besides the price (as price is not an issue)? What are some of the largest battery based systems that you have installed or heard of? Any input is welcome. . .besides being told just to run away from this one. . . REgards, Mark Dickson Oasis Montana Inc. HYPERLINK "http://www.oasismontana.com/"; \nHYPERLINK "http://www.oasismontana.com/"; \nwww.oasismontana.com No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.5/1979 - Release Date: 3/1/2009 5:46 PM No virus found in this outgoing message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.5/1979 - Release Date: 3/1/2009 5:46 PM
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