need some opinions

[who8myrice]

ok so this is the deal.

Im completely new to this type of stuff, i really dont have access to any metal and i only have limited power tools. I dont need a gigantic system, only a solar panel, maybe two, and one 12 volt deep cycle battery, im only trying to power a tree house far from any power sources. I found a cheap brief case solar panel on ebay (link to a picture below) and a deep cycle battery there also for only $40.

Solar panel:

http://cgi.ebay.com/12V-Briefcase-Solar-Panel-Generator_W0QQitemZ190007731471QQihZ009QQcategoryZ3240



QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

However, i found this wind turbine kit (i would build one on my own but as i said, no access to steel or welder or any sort of welder)Its $95 and it puts out a little over 100 watts and about 15+ volts.

It reaches around 100 watts in very low wind.. about 15-20 miles per hour and where i live, there is a constant 5-10mph breeze, with constant gusts up to 20=30 mph. Below is the link to the kit.

Kit:

http://www.velacreations.com/chispito.html

Im probably going to hook up a 300 watt inverter (yeah i know its a lot for the battery to handle but we will only be using it for an hour or two at a time, giving it a chance to recharge) and run a small TV and maybe an xbox, maybe even a minifridge (obviously not all at once, and i might buy two batteries)

I'm trying tofind the cheapest, most efficient way to power my tree house. I thank you for your time and future help

-Nate

[henjulfox]

Couple of quick observations:

1. That's a fair to good price for the solar panel. However it looks pretty cheaply made. I have my doubts it would hold up long out in the weather.
   
2. Both systems would require additional purchases. Solar panel would need a mount (probably rig up something cheap),  a charge controller (though you may be able to get away without one with more than 1 battery and/or frequent use) and the wire to connect panel to battery (copper has gotten expensive). Turbine would need a mast, guy wire, and some kind of controller (I only glanced at the kit, maybe something is included). For either a volt meter for the battery is a good idea.
   
3. Solar panel must be mounted where it gets clear sun for most of the day. Wind generator must be mounted high as possible, above obstructions. Both are problematical for a tree house instalation.
   
4. Most important - do the math. Look at the wattage requirement of any device you want to run. Also consider the capacity of the battery. Volts X Amps = Watts. You can't use more than 20-30% of the battery capacity without shortening it's life.
   
   

For example: the PV panel puts out 13 watts which would be about 1 amp. Figure 5 hours of charging on a clear summer day, it will put out 5 amp/hours. This will power a 1 amp device for 5 hours or a 5 amp device for 1 hour, or any other combination. If you TV uses 100 watts @ 12 volts it consumes 8.3 amps per hour. Each clear sunny day will power the TV .6 hours. You have losses panel to battery to inverter to device therefore you would be doing good to get 1/2 hour of TV per day (if it pulls 100 watts)

This is a fun hobby. I encourage you to spend an hour or 3 reading the various posts on this site. If nothing else you will gain an appreciation of the grid power.

-Henry

[Volvo farmer]

What's your budget for this project? Do you ever plan on adding on to the system?

If you ever want more power, you likely won't be able to use that breifcase panel or a 12V deep cycle battery as building blocks to your system. It will cost more, but you might want to consider a polycrystaline solar panel in a larger size, like 80W. It seems that below that, the $/watt figure is higher and lower power panels seem to become discontinued more often than higher ones, making it harder to build a matching array later on. 80W panels are about $450 now.

Batteries kind of have to be bought all-at-once. If you want to add batteries three years down the road, the new ones would not match up well electrically with the old ones. I think 6V golf cart batteries are much better suited to a project like yours than the 12V deep cycle/starting marine batteries. A couple of golf cart batteries will set you back about $100 at Sam's club last time I checked.

a 300W inverter might run a TV an an xbox, definitely won't start a refrigerator though.  Square wave inverters are pretty cheap nowadays and you could get up in the 1000-1500W range for $125 or so. An inverter this size might just be able to start a mini-frig, but if you ran it overnight, your batteries would likely be pretty low in the morning.

I don't know anything about the Chipisto kits, though you need to consider how you're going to mount it and where. You'll likely have some expense getting it on a tower, up in some clean air, as well as some copper wire expense to get the power into your batteries.

Here's a real good article on a small solar system.

http://www.otherpower.com/wardsolar.html

[finnsawyer]

You should be aware that there is no such thing as absolutely clean energy.  Those solar cells have to be produced at an energy cost as well as disposed of after their life span.  The consensus seems to be that the energy produced during their life is less than that needed to produce and dispose of them.  That is pretty much reflected in their cost.  Do the math.  Figure a twenty year life span.  So, what would be clean energy.  Something produced by plants that is instantly usable.  Geneticists have woken up to the fact that sea plants can produce hydrogen. Sea kelp does it all the time.  Puts it in nice little bladders.  The closest you could get today would be a methane digester.  Puts this in a different light doesn't it.  Like most things it's a matter of perspective.

[asheets]

re the solar panel -- you're pretty close to hitting the desired $4/watt pricepoint.  However, I too wonder about durability, construction, and the validity of the performance claims...

[veewee77]

That solar panel is not manufactured to live outside.  It is a 'portable' charger designed for temporary use.

Remember also that with losses, that little solar panel won't give you much usable power over a day's time.

It states 750MA and that is .75A and that works out to 3.75 amp/hours provided it could put out it's maximum power (it won't) for a minimum of 5 hours of pure, clean bright sun per day (unlikely).

So, if you figure losses we'll say for the sake of argument that you'll get 3 amp hours from the panel per day. At 12Volts, that is 36watt/hours per day.

For perspective, if your TV uses 100 watts, you can run it about 20 minutes per day on that much power. 100W divided by 36 watt/hours = .36 hours or about 22 minutes.

Then, remember also that you will lose about 20% of the power that is sent into the battery to charge it in losses.  So if you take that 22 minutes and shave 20% off it, that works about to 7 minutes so now you are at 15 minutes you can run the TV after a full day of good sun.

Do as others have said. . . get a bigger panel. . .

The refrigerator is out. Get an ice chest and use ice made in the house refrigerator. . .

For batteries, don't waste the money on those marine/deep cycle batteries from the local Big Box Store.  Get true deep cycle batteries (like 6V golf car batteries) and get them in pairs. You can get them at Wal-Mart and auto parts stores for anywhere from $49 (too cheap, may not be any good) to over a hundred each for the best ones (unnecessary for the application).

First things first. . . HAVE FUN!  Start small, learn what things will (and won't) do and then build your system as you go.  You will learn a lot by doing.  Asking questions before spending money is a good idea to keep from wasting money on things that won't do what you expect them to do.

Doug

[who8myrice]

yeah i was thinking the same thing as you were about the durability of it, however im looking to stay very cheap and this did seem like quitye a deal, if i like the first one, i might get a second one.

Also, i was wodering why it would be better to switch to a few (3-4) 6 volt batteries instead of 1-2 marine deep cycle 12 volt batteries.

Finally, i was also wondering how i would connect the panels to the batteries and how i would wire all the betteries together. For connecting the panel there is only like a 5 foot cord with battery clips and another short cord that is a cigarette lighter plug. obviously the batteries arent going to be 5 feet from the panel so should i just buy a cigarette lighter and then lengethn the wires and then connect the wires to the battery, and then plug the panel in to that.

And finally, it would be extremely appreciated if someone gave me some sort of a picture of how to wire multiple batteries together.

I greatly appreciate this, thank you

[who8myrice]

ok, so i now realize that to make it even work i would need like 3-4 of those panels.. and they do not look like they are very good quality, so im just going to buy a larger, more powerful one.

I'm working on my dad's web site and even though he's gonna pay me like $400-$500, i'd really rather not spend it all on a panel. I was hoping that one of you guys could recommend a good, cheap, and efficient panel, or set of panels, that could power a small TV (probably 13", maybe less) and an xbox.

It would also be appreciated if someone told me what amp/ hours meant

and finally, it would be great if someone told me how many of the golf cart batteries would be needed to run an xbox and the tv for around 1 1/2- 2 hrs.

I thank you for your time,

-Steve

[who8myrice]

also, what if i just went to my town dump and took batteries out of old cars there? that would save me a TON of money, i copuld get like 20 batteries for $10 lol

would this work?

[Countryboy]

Hi Steve,

  No one can truthfully tell you how many batteries you need to power an xbox and a tv for a couple hours a day UNLESS you tell us how much power the xbox and the tv will consume.  Without knowing those things, we're just guessing at best.

Hey, if you can get a good deal on auto batteries at a junkyard, go for it.  You might want to take a hygrometer and volt meter with you to test them to make sure they are in good shape before you buy them.

A deep cycle battery is going to be a lot higher quality battery and last longer than an auto battery.  However, if you can buy the car batteries cheaply, they will work for a while.  Since this is just a treehouse to goof off in, it's not going to kill you if you miss a day without power due to a battery going bad.  If you were depending on a car battery for lights and water and other essentials to keep a wife happy, the deep cycle battery would be your best bet.

If truth be known, I would say that most people who involved with DIY renewable energy used a battery bank of car batteries at some point.  Why?  Because they can be had cheaply, easily available, and because they will work for small systems.

It may be worth your while to stop by a golf course if you have one nearby.  Often, they throw away deep cycle golf cart batteries if the battery dies before they make it back from the 9th hole.  If the battery is only good for 8 holes, it's worthless to the golf course, but 8 holes worth of power may be more than enough for what you need.  Ask the golf course if they will make you a deal on any old golf cart batteries.

[RP]

Yeah, used car batterys will probably be fine for starting out.  Since you're really trying to work on the cheap get one and start from there.  You can try adding more later or replace with a pair of golf cart batterys.

Look at the back of your TV and your Xbox to see how many watts the use.  Add them up and divide by 12.  Now you know how many amps they draw when being used.  Add about another 20% or so to cover the losses you'll have in the inverter.

Amp hours is a measure of energy usage.  One amp hour is 1 amp multiplied by 1 hour.  10 amp hours is 1 amp for 10 hours, 2 amps for 5 hours, 10 amps for 1 hour, etc.  

If your TV and Xbox draw 134 watts for example then multiply by 1.20 (the 20%) to get about 161 watts.  Now divide by 12 to get about 13 amps.  13 amp hours of battery capacity will run your system for 1 hour.

There are other factors like depth of discharge on your battery (how dead you allow it to go) but hopefully this helps.

[richhagen]

Most of the cheap amourphous type panels I have bought and obtained over the years aren't up and mounted anymore, because the thin film layer started peeling away, or the output voltage just went down.  Better to spend a little over a hundred bucks on a tempered glass front 10 to 20 Watt, EVA encapsulated mono or poly crystaline type panel that will likely last a very long time.  Some of the old used Arco panels I have are from at least the 80's and still producing.  I would almost be surprised if a some didn't make it to a hundred.  No one knows how long these types of panels can last because many of the first ones made are still working.  The last I knew, the first solar panel from ATT Bell Labs was still producing power on their building, and it had been there for about 50 years (from about 1954).  None of the 25 or so mono and poly crystaline panels of this type of construction that I have have ever failed (although I've had to re-do a connection or two).  I think you get a much better $/kwh over the life of the panel from those panels.  Some of the small BP 10 Watt glass panels don't look like bad of panels to me, although at $10 a Watt, they are very expensive, and I do not own one.  They are however about the smallest new panels that I have seen where I would be comfortable with the construction.  I have also seen some used Siemens Panels on Ebay recently go for about $4 a Watt.  Those are in my opinion, a much better value, but the overall panel cost for an SM-55 is still a little over $220 to your door. Quite a bit more power than what you were looking at, but quite a bit more cost as well.  Still it is cheaper in terms of dollars per Watt, without even considering the remaining lifespan.   Rich Hagen

[who8myrice]

Thank you so much everyone! your help is greatly appreciated. However, i do think that i have decided to build a wind generator instead of buying solar panels. With the generator i will only have to spend around $70 and i'd be producing double to triple the amount of power that I would get from a solar panel (using an amatek 50VDC)

where i live there is constant 24/7 breeze, so that too works out. I wouldn't need to mount the generator any higher then 6 feet or so and i'd still be bringin i a fair amount of energy

So i thank you all for your opinions and advice!

[ghurd]

Do some Googling about the Amateks as generators.

I seem to recall a chart on some website showing different voltages and their outputs, and the 50V was NOT a good choice. 30 to 40V is a lot better.

G-

[VisualMonster]

You may have seen my other posts about the 45w panel I bought at Harbor Freight:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599

If you use a 20% off coupon you can get them for $160, coupon here:

http://www.billt.com/harborfreightcoupons.htm

This kit even comes with a charge controller and two 5w light bulbs which might be perfect for the tree house.

Otherwise the wind turbine is probably the way to go, cheaper and you'll get continuous power, even at night.