Just Curious..

[12vman]

I'm totally off grid and have been for several years. I'd really enjoy knowing about projects that others have going on using PV.

I have two separate systems. One that runs the house and a smaller system for outdoor lighting. Neither one is huge. The house runs on 512 watts and the outdoor lighting system consists of 96 watts.

The house system does everything I need it to do and the outside system is my "toy". I'm always building lights and stuff doing experiments. ;D

[Backwoods_Bob]

We have been off grid for ten years now.

Our cottage is powerd by a 480 watt solar array and a small windmill.
:)

We heat with only wood, use propane to run our stove, frige and a big chest freezer, don't have running water and we use an out house.

Our array -

http://i123.photobucket.com/albums/o320/etdbob/guns/P1010173.jpg

[12vman]

Howdy, Bob.. Good to see ya! I's wondrin' where ya been..

Ain't this stuff great! ;D

I wouldn't trade it for nuthin'..
~Don

[johnjmw]

I am getting ready to install a system at my BOL. I'll get you all the details and problems as I run into them This will be a camping cabin till I get my real cabin built. Already have 4 125W panels to install and will be looking at building a small wind genny to get through cloudy weeks. I already made one small mistake, Trying to save a few bucks I went with deep cycle marine batteries instead of the better golf cart batteries. I figured I'd save a few in case I really messed up and ruined the first set by not having the float charge rate set right.
John
PS Bob, don't know which caught my eyes first, the gear or the panels! Liked them both!

[cinok]

I am so envious I wish i could talk my family into doing it

[12vman]

johnjmw..
You can do quite a bit with that wattage. I run everything around here on 512. 8)

Those marine batteries will be fine for a starter. For that amount of wattage, you could charge 4 or more if they are the larger ones. (60-70 aHr. ea.)

What charge controller do ya have? I'd figure a Xantrex C-40 or something like it. Set the bulk charge around 14.4/14.6 and the float around 13.6/13.8 and you'll be OK. Just keep some distilled water around and keep an eye on the levels in the cells. Check them once a week in the begining and if they boil too much during the bulk charge, back the voltage down just a notch. (14.2/14.4) Leave the float charge alone. (I'm assuming a 12 volt set up) ;)

cinok..
What are some of the fears you're family has? Ain't the blow drier thing, is it? ;)

~Don

[johnjmw]

I am under the impression Don that they are 110aHr each. I'll be using an MX60 charge controller. I upgraded the controller so I could wire the panels in series (24v or more) and the controller would step it down to 12v. That way I can use slightly smaller wire from the panels combiner box to the batteries charge controller.
I had to go with the "More power" because I promised my wife to be able to enjoy a few of the toys of city life. Ok, they are not all hers. and I am one who likes to leave the radio on most of the day while I am working inside.
The first installation will be temp. till I build but then I build I might be too deep in the woods to have the panels close by. Unfortunately I'll have to set the charge controller on the safe side because I am not there for a month at a time some times. I will have to look at the batteries again to see if they suggest a setting for the bulk charge, I thought the MX60 allowed 14.4 or 14.2 (not as much gassing) but would take longer to recharge. My biggest worry is attaching the panels to the pole in a way I feel they wont "accidentally" disappear while I am not there. Then there is the combiner box???? I really don't want to install that at the panels but that is where it belongs. The DC breakers do make it easy to do the wiring at least.

John

[12vman]

WOW.. 110 aHr. marine batteries.. Them's biggin's! They oughta do the job. I figure about 4 of them?

MPPT is a new concept to me. I'm old school in my set up. I have a C-40 controller with 2 ga. wire between the panels and the controller at about 30 feet. Ain't much line loss there.. LOL MPPT makes sense, though.

Wish I had some pics of my panel combiner. I used 10 ga. wire ran from the panels through plastic conduit to the area where I built it. I used (2) pieces of 1/2" copper pipe (2' long) and soldered all of my connections (pos. and neg.) to the pieces and stuck the 2 ga. in the ends and mashed them shut on the wire and soldered that too with a torch. Sealed the ends of the conduit with vapor shield so bugs couldn't get in. Soldered caps on the unused ends of the copper pipe for the same reason. Maybe overkill but I'll never need to mess with it for years, I'm sure. It's exposed but weather isn't going to bother it. Everything is soldered and sealed! It's right behind the panels on the platform behind the panels in my avatar. I just have each piece of the copper pipe clamped down to the wood..

The only time the batteries will boil heavy is if they have a discharge. If they aren't used, the bulk will ramp up quick and go to float. That's the crucial setting in your case. At 13.6 - 13.8v they'll fizz like soda pop. Trust the controller. They're pretty smart..

That's why I have my panels on poles. I didn't want to see them walk. I got ripped off 3 times.. big time, but they didn't get the panels..

Good luck! Keep us updated!

[cinok]

It mainly just a prority thing. If it was up to me we would be in the middle of nowhere solar, drawn water. But she got through nursing school and enjoys her job still working on her BSN

[12vman]

I totally understand. It's a big move and a lot of work..

I still do my career and I drive 84 miles round trip a day. Everything has it's price, it seems.. :-/

[johnjmw]

Yea, it's not easy to decide until you experiment a little what you are willing to give up, but with my wife's health,,, I don't want her to have to give up simple pleasures. As long as it is reasonable that is. I can always add some more power, :) for the right reason.
The combiner box I am using is a Nitesolar 6 breaker box. Since I bought 4 panels I was sold 4 150v 15A breakers to combine them into a +/- 12v 28A bus. Instead I'll be wiring 2 in series and then feed them into the combiner at 24v 7A each leg. That was the wire from the combiner to the MPPT controler, which will step up or down the voltage and current for optimum charging of the batteries. I've found more lights and such for 12v than for 24v dc so the batteries and cabin will be wired for 12v. Some times I've wondered about taping 12vdc from a 24v wired battery. The only two 24v items I really am looking at are ceiling fans and well pumps.
John

Oh, how high up the pole are the panels? I was looking at the top of the panels at about 6ft or so

[12vman]

Quote..
"Some times I've wondered about taping 12vdc from a 24v wired battery."

Don't do it! When you "Half Tap" a battery, it causes all kinds of headaches. The 12 volt load is pulled from one battery and unbalances the load that the controller "sees". The battery that is drained the most takes the brunt of the charge and boils the crap out of it..

The platfrom that my panels are mounted on is 20' high. It's made with 5 telephone poles. (one in each corner and one smack dab in the middle) It ain't commin' down... LOL

You'll find more products that will operate on 12 volts than any other D.C. voltage. That's the reason I went with a 12 volt system. Makes life a lot more simple..

[rAcErRicK]

Hello Don, If you don't mind 12vman, help me out with a small problem, please. I have a friend who has a golf cart. We installed a set of small driving lights on it, and I tapped off of 2- 6v batts.
After reading what you just said, what would be a better way to get 12v for the lights ? Thanks in advance.

[jott]

The easy way would be to have enough lights to equal the voltage of your battery bank. Wire the lights up in series. But the problem with that is when one light burns out they all go out.

The best way to do it would probably get a DC-DC converter for whatever the battery voltage is. I think 24V-12V and 48V-12V should not be too hard to find for the power needs of driving lights.

[12vman]

I agree. Keep the load on the whole battery, not part of it.

I figure the driving lights to be around 5 amps each. One of these (http://www.tessco.com/products/displayProductInfo.do?sku=67551&eventGroup=4&event Page=1) or something like it should work.

[cinok]

My wife and i used travel the countryside in a semi we had all kind of 12v acc for the truck mini fridge, crockpot, lunchbox cooker,tv/vcr,fans ect. For a basic setup this might work for some startups

[Umbriel]

*snipped the extra out*
That's why I have my panels on poles. I didn't want to see them walk. I got ripped off 3 times.. big time, but they didn't get the panels..



Can you explain this part a little more 12vman? *Hubby and I are planning our system right now and this caught my eye as something that we might need to prepare for. *Thanks! *:)

[12vman]

Umbriel..

I figure if the panels are 20' off the ground it would take some effort to get to them instead of being just on the roof or on the ground.. Granted, a chain saw would get them down but they would probably be destroyed in the process.

[Umbriel]

12vman,

Do you use a ladder to clean your panels when they need it? Part of our plan is having only a single story home, so that when we are elderly we won't have the difficulties of dealing with stairs. We were thinking of installing the panels on a platform that we could reach easily with an extender pole for cleaning. So not on the roof. 20 feet is high though! It sure would keep all but the most determined thief from stealing your panels, lol.

[12vman]

They don't need "Cleaned" often. Rain seems to keep them clean enough..

The only time I have any issues is when it snows heavy. I kinda found a cure to get the snow off easily without climbing up to them..

I use a kids toy.. A "Super Soaker" squirt gun filled with windshield washer fluid. I pump it up and squirt my panels from the ground. I break up the snow a little and the sun does the rest.. ;D

[DavidOH]

a kids toy.. A "Super Soaker" squirt gun filled with windshield washer fluid. *;D

Ingenious. 8)

[12vman]

Yep.. That Super Soaker has become a rather useful tool..

http://www.backwoodshome.com/forum/yabb/forum.pl?board=gen-general;action=display;num=1217273786;start=4#4

As for the windshield washer fluid on the panels, I haven't seen any problems.. ;)

[Umbriel]

I'm gonna steal that super soaker idea, no shame in my game! :P

[12vman]

"I'm gonna steal that super soaker idea, no shame in my game!"

Go for it! That's what this place is all about.. ;D