Newbie going off-grid, tons of questions
By thomahal, Section Newbies Posted on Sat Apr 04, 2009 at 10:24:24 PM MST
First one is how much trouble my cheap impulses have gotten me into already.

Hi folks,  Appreciate this site --lots of great information.  But esp. a newbie section because I think there are a lot of us that are interested but mighty ignorant.  And that would be me, for sure. My monthly electricity use is pretty well always below 100kwh/month, usually around 50 or so (I live VERY weird). I have very little money to work with.  I live on 'bout the highest point in Andrew county, Missouri --ok, not exactly the Himalayas, but seems like there is pretty great wind (there is a relatively new wind farm in the next county over, visible from my place). OK, I have purchased an air-x 400watt 12volt wind turbine.  I have a 3000watt (6,000 peak) modified sine wave inverter (12volt).  I have a pretty great tower that's been around forever, but I'm not sure how tall it is when put up. Those are in hand. I have a TON of questions, but I will start with this one.  I found a 175 watt monocrystalline 24volt BP solar panel at auction for $340.  It was new with some frame damage according to the listing, tested: full amps/volts.  This seemed incredibly cheap and I pounced.  It will be on the way soon. What can I say, I am C-H-E-A-P. Soooo, now I am trying to figure out the best way to use the 24volt panel with the 12volt turbine.  I am looking at 24volt to 12volt converters which seem to be very reasonably priced, but I have no idea how much electricity is lost using one of these.  I know the batteries (not purchased yet) could be 12volters wired in a 24volt charging pattern and I think with some blocking diodes they can still put out 12volt to the inverter(?).  But I'm not sure how the 12volt wind turbine would fit in to all that. Here's my best guess so far. I'm looking at a tri-star 45amp controller and am thinking if I can install the 24volt panel on top of the barn, use the advantages of the 24volt reduced wire size to get the 100 yards or so to near the controller, reduce the 24 volt to 12 right before connecting to the controller, and then have both the wind and solar go into the controller at 12volt, I will still be ahead of the game given the cheap price of the panel. First question, does this make ANY sense?  Second:  If not, in simple language please, what is a better solution?  Thanks for any input.  I have lots of questions about the controller and batteries as well if there is an opportunity for follow-up.

Newbie going off-grid, tons of questions | 9 comments (9 topical)

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#1) by wpowokal on Sat Apr 04, 2009 at 06:31:34 PM MST

Highly probably your 24V panel is 2x12V, take the cover off the junction box and post a pic. allan down under "Dream as if you'll live forever, live as if you'll die today." James Dean

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#2) by jlt on Sun Apr 05, 2009 at 06:57:59 AM MST

If you haven't used the air x sell it now. had one and they are junk. with the money build a 10 to 12' machine . neighbors complained about the noise from it .they live 1/4 mile away.

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#3) by Bruce S on Mon Apr 06, 2009 at 02:04:33 PM MST

I have not used an Air-X, but have seen one up at an "energy-show" close to home here in St. Louis. Do as others have said dump the thing and get something else. Having said that IF you must stay with this one, google this site and look for better blades. I can see that you're up around St.Joe and Omaha. Look on NREL site for wind charts and see about getting tower based winds speeds, let these people know and I'm certain they can give you some options. DO NOT go cheap on the mounting of the turbine, stay safe and at least it'll give you something. The panel: Surely look at the junction box, open it and you should be able to split it off into 2x12. 100' may be stretching it for solar panel's connecting wire , but should work, and use multi-stranded wire, easier to work with and normally cheaper. Think extension cords :-)). You can use the panel like it is, charge at 24V and use the batts in a 12V configuration, it'll work just becareful of the layout so the two circuits don't meet i.e. Grounding should not be common either. Head out to a Thunderbird truck stop and have a look around for 12V switch over circuts, they'll have the amperage carrying ability for going this route. Good luck with it!! Bruce S

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#4) by thomahal on Tue Apr 07, 2009 at 08:09:12 PM MST

Hey, Thanks for all the responses!  I don't have the panel yet, supposed to arrive around Thursday.  I asked the people selling it (www.solarblvd.com) re: rewiring before bidding and haven't got a specific response from them yet.  I will post the junction box when it comes in.  I was hoping it would be that straightforward. I am reconsidering the 100 yards to the barn roof.  May go with the garage roof instead, risk a little shade on the monocrystals, and have like ten yards to go instead. I have found some 10 and 15 amp voltage reducers in case need to go that way (http://www.opektech.com/Voltage_reducers.html). Like that they take a fairly wide range of voltages, but I have zero experience with these things.  Anybody want to take a look, might help others if nothing else.   I actually got about 50' of #14 AWG extension cord and a 10/4 hookup for 220volt appliances for 5 bucks at an auction this weekend.  Will read up on this site how best to utilize them in my system, but do hope they come in handy. On the Air-X.  Ouch.  Got it for $440 with S/H new and want it to work pretty bad.  In the literature they claim they are a lot less noisy than the 403 models (?) and I do live a HALF mile from the nearest neighbor, so maybe worth a shot :)?  I am planning to build a second one myself ...but I know myself well enough to know what that means:  tons of daydreaming work, MAYBE getting something done this decade. BTW, I'll add one more question here.  Also in the Air-X literature they swear up onside and down the other that I do NOT need to hook it up to a charge controller.  The internal controller is supposed to work BETTER hooked directly to the batteries.  Am I right in thinking there might be some skepticism hereabouts? [ Parent ]

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#5) by spinningmagnets on Tue Apr 07, 2009 at 09:34:07 PM MST

I have never owned an Air-X or 403, but you may find this interesting. http://www.fieldlines.com/story/2008/12/4/61856/1082 [ Parent ]

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#6) by ghurd on Wed Apr 08, 2009 at 09:09:02 AM MST

http://www.fieldlines.com/story/2005/8/22/123113/162 http://www.fieldlines.com/story/2005/10/15/145557/02 Too much Air-X data available, most of it unflattering. G- Ghurd.info [ Parent ]

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#7) by thomahal on Fri Apr 10, 2009 at 08:17:36 PM MST

Have read all that about the Air-X.  Sounds grim.  However, I have to say I would be kinda surprised if every single turbine they have ever sold have never turned at all.  Sounds just a little TOO bad, like other things sounding too good to be true. Have not seen much response to the possibility that the main cause of the problems have been the grossly undersized wiring usually used.  The one guy recommending #4 awg wire.  Hugely expensive, but if it keeps the turbines from reading the reduced current flowing through the too-small wire as batteries that are going to overcharge and then putting the brakes on to stop this, that would SEEM to be a fairly reasonable explanation for some of the problems/horror stories I read about.  Does this not seem possible to you-all that know tons more than I do? I have done nothing but open the box so far.  It is possible to sell the thing and recoup pretty much all of my money.  So would appreciate any follow up/thoughts. While I'm at it, I'll add another question.  There is a place within driving distance that sells 6volt batteries as seen here: http://www.usbattery.com/usb_usl16hcxc.html.  They are "US Battery" models - "L16HC XC AH-Capacity 420."  They are new, though I didn't catch the MFG date yet. Warranty is only one year replace, two year pro-rated replace.  They SEEM to me to be comparable to the trojan L16HC but the price quoted ($191) seems about almost half some of the trojan prices I have seen.  I did a search of this board, but came up with little about US Batteries specifically.  The salesman said he has a customer who has used them with solar power and has had great long-term success. Yep, that is from the salesman, but still.  Any ideas? [ Parent ]

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#9) by RandomJoe on Sun Apr 19, 2009 at 09:35:31 AM MST

I don't have the Air-X, instead the Air Breeze, which is rated as a 200W turbine.  I'm certainly no expert, but my observations of this one indicate the wire has a LOT to do with the thing's performance, far more than I ever thought it would. When I first got it, I made use of an existing run of 12GA wire to get to the batteries.  I had a couple of WattsUp meters inline too, one out at the base of the tower, one at the battery.  I had all kinds of problems.  The voltage went all over the place, including well above the regulation setpoint I had set.  (I saw a few peaks around 18V!) I finally decided perhaps it was the wire, so ran a new circuit for it using 8GA wire.  Things calmed down considerably after that.  But I kept having erratic performance.  I didn't have anything to log performance at that point, so kept relying on the WattsUp meters.  What I finally realized was that the thing did quite well when the meters weren't inline.  I would see it doing well on a windy day, and decide I wanted to see what it was doing, stick a meter inline and little or nothing... My assumption based on that is that even the small "bump" of the thin wire on the WattsUp meters was enough to give the circuitry fits.  As long as I have a low-resistance path to the batteries, the turbine does pretty well.  Now that I have the Outback DC monitor in, I'm hoping I can finally see it doing well.  But I haven't had the right wind since putting that in. Although mine is really more of a(n expensive) toy at this point, it rather surprisingly - given the track record of their previous turbines - produces very close to the power it is claimed to, at the wind speeds they claim.  (Wind speeds measured by my weather station mounted nearby.)  My problem is that I'm in a terrible wind location, and can't mount it high enough.  (The city actually has a ban on turbines, so I'm keeping it "under the radar" so to speak.)  So mine probably won't do much until next winter - north winds are about the only ones that consistently get it going very well.  It's still fun to watch... ;) [ Parent ]

Re: Newbie going off-grid, tons of questions (3.00 / 0) (#8) by wooferhound on Sun Apr 19, 2009 at 08:42:30 AM MST

When you get you solar panel, Check the Open Circuit voltage in full Sun, if it is putting out 21 or 25 volts then you should be able to use it fine on a 12 volt battery without messing around with the voltage at all. W o o f -={(

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