Oct 25, 2006 09:09 pm
Re: Multiple off grid systems
Carlos,
I manage a private, 45 acre island 65 miles SE of Nassau, in the Exumas, Bahamas. I am currently doing a major AE installation, and I've opted for several "stand-alone" units for the following reasons: I am totally against the cost and complexity of running wireing in conduit all across the island. I WANT the redundancy of multiple systems, so that if any one location gets hit by lightning, the whole shebang ain't zapped. Each location will have a bank of Absolyte II batteries (or, perhaps the Deka Unigy II's...), and inverter (most likely by Outback--they provide a TRUE sine wave, and are SEALED against the elements!), an appropriate set of panels, and a Whisper 100 windmill (am considering a Bergy or two for comparisons...). Your battery bank is the HEART of your system. Like with cistern size, no one has ever said, "Gee, I sure am glad I let them talk me into the SMALLER unit...!". Consequently, the more the better. Each location here will also have it's own small (8kW) diesel generator as back up and emergency power (this also allows A/C in the hot months...) Each generator is "semi-portable" (built in, but permanently mounted on a small trailer), to enable pulling duty at different locals.
Here, I have one owner, his immediate family, and a precious few "mainlander" guests. These are all "dialed in" to the alternative energy lifestyle. This is a MUCH bigger issue than folks here have implied. ESPECIALLY if you have a coupla dozen bungaloes loaded with tourists (or, as I inaffectionatly call 'em, "turroids"). Folks on vacation will smile, nod their heads, agree wholly, then go ahead and plug in their hair dryers, take loooong showers, and leave the friggin tap running whilst they brush their teeth. Believe me, the laundry doing TOWELS alone will drain an astonishing amount of precious h20... Which brings us to your watermaker demands. At my warehouse, I have two Watermakers brand 2500 gpd desal units. I also have a cistern with 70,000 gallons capacity (additionally, I have an island-wide capacity of +/- 120,000 gallons). And, we USE it!! My intent is to run "mr. stinky" for a day or two here and there, to top off the tanks. DON'T simply "run it for a half-hour a day", as this is not good for the watermakers (btw, what brand/size desal do you have?). That said, I have just been notified of a watermaker motor retrofit that WILL run on AE. Check the Danfoss SWPE for info...
So, there's my fifty-seven cents worth. Cheers!
J. Chris Cloud