Playing with solar

Tue Feb 28, 2012 6:09 pm

At our farm we don't have electric power. And the closest line is over 1/2 mile away and running a line up to our place was way more than we wanted to spend. We were running off a generator when we needed power but that was expensive to run noisy and a pain to start it up and shut it off all the time. In 2008 we got a used forklift battery 5000 watt power inverter and two small 110 watt solar panels. I had power 24 hrs a day and only had to charge the battery every third day for five hrs. The solar panels were on the shed in the woods and were in the shade so they didn't work very well but was good enough to keep the charge up while we weren't there.

Last fall one cell in the battery went totally bad and needs to be replaced. But we went out and bought a new and larger battery last December. The end of January My brother Tommy and I went changed batterys and moved the solar panels out to where they can get good sun. We also bought partially built 225 watt solar panels that we are working on putting together. And are planning on putting up ten of them at the farm. Which should be enough so we don't have to run a generator at all.

Each of the new panels will be a little larger than both of these put together.

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After moving these panels out in the sun we were getting 7.6 amps of charge at 24v which would be 15.2 amps at 12v. By looking at the charge controller the panels are putting out 28.6v and the battery is at 27.1v

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Before moving the panels the most we could get was 2.5 amps. But even covered with 1/4 inch of ice and some snow the panels were giving 2.2 amps of charge. But even at 17 deg once the sun hit the panels it only took 1/2 hr to melt the snow off of them.

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This is out power shed where the panels were mounted on.

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This is the new battery 1500lbs. The old one was 1100lbs. With the new one it should last 5-6 days with out any charge going into it. Definitely one big battery!

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The power inverter is the silver thing above and to the side of the battery and the charge controller for the solar panels is mounted on the 4x4 infront of the lawnmower.

Billy

Re: Playing with solar

Tue Feb 28, 2012 6:42 pm

Man you are really at it. Do you use the Lister generator?

Re: Playing with solar

Tue Feb 28, 2012 6:47 pm

Bill:

Do you have a cost break down on the set up?

Nice, very nice.

Re: Playing with solar

Tue Feb 28, 2012 9:09 pm

Great pictures, Billy. Really proud of what you are doing there. :D :D

Re: Playing with solar

Wed Feb 29, 2012 11:29 am

Hi Bill

We are using a chingfa generator. Eventually we are going to change it out with a lister. But the chingfa was ready to go when when we started putting things together.

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Hi Eugene

The 5000 watt inverter was $469 when I got it but they are $20 cheaper now. Its not a pure sine wave inverter but we haven't had any problems running table saws, power tools, Tv, microwave, computers and anything else at the farm. Pure sine wave inverters are at least twice the cost. Use three times the power at standby and are 10 to 15 per cent less efficient under a load.

I am running a 24v battery and inverter. I would run 48v but the equ is a big jump in price. 12v and 24v are about the same price. But it lets you save money by running smaller cables. Also charge controllers charge multiple battery voltages but are limited to their out put amps. So you can use the same CC for 12v or 24v but you get twice the power output by going 24v for the same costs.

http://www.theinverterstore.com/the-inv ... inv500024w

The charge controller is a combination solar/wind unit that came with a 750 ARI wind generator. Its not real efficient with solar. When I get a CC for the new panels I am planing on getting a Outback MPPT 80 amp 150v CC and those are about $750. I feel I would be wasting my time with anything but a MPPT charge controller. They are about 30% more efficient allow you to run higher voltage into it letting you run smaller wire. And running higher voltage will allow the panels to charge on cloudy days where with other CC you won't get enough voltage to charge. With other CC than MPPT it just cuts off any voltage past what is needed to charge the battery where as a MPPT uses all the power from the panels.

When matching any solar panel or series of panels to a charge controller. You need to take the Max Open Circuit Voltage and times it by 1.56 and make sure the result is less than the max input voltage of the CC.

Its hard to tell on the panels we got but I think they are going to cost around $170 a panel. Not including labor to assemble them. We bought a pallet of blemished panels. Then had to buy aluminum and bend it up to make frames. Get and install junction boxes and assemble them.

Most people use banks of golf cart type battery's. But I prefer a forklift battery. With banks of batterys you have a lot of battery post connections to keep clean, they take up more room, they don't last as long, if you charge them too hard it shortens their life. There is a formula to figure out how hard you can charge a battery for max life but on a golf cart battery its about 10 amps. Where as with the forklift battery I can charge it at 180 amps without hurting it.

You cannot tell the state of charge of a battery by voltage. That will only get you close. The only real way to tell is to check each cell with a hydrometer adjusted for temperature of the battery. And there are a lot less cell to check on a forklift battery.

The battery really is the heart of the system. It needs to be large enough to easily supply the inverter with power at max loads for as long as it needs it. For my 24v inverter putting out 5000 watts it needs to put out 208 amps. If I was running a 12v inverter it would need 416 amps. Which shows why it is better running a higher voltage system and dropping wire sizes.

Battery life also depends on how often it is cycled x depth of discharge. Also not keeping it fully charged will shorten its life. A lead acid battery looses 1% of its charge a day so in ten days you have lost 10% of the charge. And that apply's to our cub batterys too keeping them fully charged will make them last longer. You also want a battery that is big enough to supply your power needs for a min of 2-3 days to be able to handle your power needs on cloudy low light days. The battery I have now will run my place for 5 to 7 days without getting any charge.

The first battery we had we got for $750 was used and used hard. The plates were sulfated which meant it had much more internal power losses than a new battery would. But even though it in the three years we used it. It paid its self off 10 times over in fuel and maintenance costs of running a generator. And having electricity 24 hrs a day priceless. Plus trying to keep the old battery going taught us what we needed to do to keep our new battery up and last the longest. And well kept up this new battery should last us 25 to 40 years. The new battery from GB battery cost us $3188. So if it only lasts us 25 years it cost us $127 a year to use and it lasts 40 years which it has for some it would only cost $79 per year.

http://gbindustrialbattery.com/Forklift ... one15.html

We still have to get material to build the racks for the panels and build them. And clear the trees from where we are going to put them up. And being on the 48th parallel it needs a lot of space to catch the winter sun. But its coming along.

Vince

Its been a big learning experience. And is taking a lot of time to figure out even what questions we need to ask to do what we need to do. But I have always enjoyed the challenge of leaning :{_}:

Billy

Re: Playing with solar

Thu Mar 01, 2012 12:18 pm

WOW is all I can say!!! Kevin :shock: :shock: :shock:

Re: Playing with solar

Thu Mar 01, 2012 2:17 pm

I think I know who should be designing hunting cabins!

Re: Playing with solar

Thu Mar 01, 2012 7:16 pm

Thanks Kevin :{_}:

Thanks Outdoors4ever

That's our bunk house. Its a 12x20 room with the wood stove hooked to a 26' travel trailer. With a 10x16 covered porch. I haven't built any hunting cabins yet. But I do go up and stay there a month at a time.

Here's the porch build.

viewtopic.php?f=4&t=65971&p=537830

Billy

Re: Playing with solar

Fri Mar 02, 2012 12:21 am

Still need to get up there for a real bonfire and kick back!!!! HD will be going soon and its used to me taking it down fireroads for fun!!!! It would love to get up there and spend a night under the stars!!!! Kevin ps,,don't need power for that,,,haha!!!

Re: Playing with solar

Sun Mar 04, 2012 11:22 am

That would be great Kevin. But we set up tents in the barn for safety. You're in the wild there I've seen bears, wolves, coyotes and bob cats from the front porch.

Billy

Re: Playing with solar

Sun Mar 04, 2012 8:48 pm

cowboy wrote:That would be great Kevin. But we set up tents in the barn for safety. You're in the wild there I've seen bears, wolves, coyotes and bob cats from the front porch.

Billy

That's OK, Billy. Kevin won't hurt them, but he might talk them to death! :shock: :lol: :lol:

Re: Playing with solar

Sun Mar 04, 2012 9:00 pm

Denny Clayton wrote:That's OK, Billy. Kevin won't hurt them, but he might talk them to death! :shock: :lol: :lol:


:bellylaugh: :bellylaugh: :bellylaugh: :bellylaugh:

Bill

Re: Playing with solar

Sun Mar 04, 2012 9:20 pm

Billy,

Now I know why you are taking all those trees out….. lots of direct sunlight, you must plan on supplying power to all your neighbors! :D

Seriously, that is a real nice set up, you did a fine job, and it should keep you in power for a while.

Thanks for sharing,

Re: Playing with solar

Mon Mar 05, 2012 10:22 am

Good one Denny :{_}:

Thanks David

My plan is to be able to live there full time and not have to fire up a generator for power.

Billy

Re: Playing with solar

Mon Mar 05, 2012 10:50 am

Billy,

I read over your description of your setup. My head hurts. :lost: There is something about electricity that shocks me. :) :)

Bill