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MIJoe
08-17-2011, 10:05
Greetings.

I would like to put together a solar power charging kit (for 12V batteries).

My knowledge on solar anything is very limited...other than the solar panel(s) and battery(ies), what else is needed?

Does somewhat have a complete list of everything needed?

Thanks!

Joe

ric0123
08-17-2011, 17:40
More than likely, a charge controller to go between the panels and the battery.

A parts list is easy, the sizing of the system and of those parts is not. The real question is, what are you planning to do with this?



Cliff notes version:
Depending on where you are in the hemisphere and time of year, you'll only get 5 hours of sunlight a day on a fixed panel. If you're still in Florida, that's a good thing


So let's say you have an 80 watt panel, which puts out about 4.5 amps
4.5amps x 5 hours = 22.5 total amp hours.

Now, 22.5/ 24 hours in the day means you get about 900ma of usable continous power.


Your battery should be minimum 4 times, preferably 10 times the capacity of the maximum output of your panel. So if you have an 80 watt panel that puts out 4.5 amps, you should have at least a 50 amp hour battery.



There's a LOT more involved, but that's the bare basics

MIJoe
08-18-2011, 05:20
Ric0123

Thanks for your helpful comments - I really need to read up on solar equipment.

Intended use would be during times when power is not available (hurricanes, etc), so I can:

1. Run a small (car travel type) fridge, mostly to keep insuline for family member

2. Couple of lights

3. Charge AA batteries for flashlights, FRS radios, notebook

Appreciate your suggestions

Joe

BMH
08-18-2011, 05:37
This website offers science kits for kids. They have a couple of solar power kits and a solar battery that might be useful: http://www.sciencekits.com/electron.html

quake
08-18-2011, 08:54
More than likely, a charge controller to go between the panels and the battery.

A parts list is easy, the sizing of the system and of those parts is not. The real question is, what are you planning to do with this?



Cliff notes version:
Depending on where you are in the hemisphere and time of year, you'll only get 5 hours of sunlight a day on a fixed panel. If you're still in Florida, that's a good thing


So let's say you have an 80 watt panel, which puts out about 4.5 amps
4.5amps x 5 hours = 22.5 total amp hours.

Now, 22.5/ 24 hours in the day means you get about 900ma of usable continous power.


Your battery should be minimum 4 times, preferably 10 times the capacity of the maximum output of your panel. So if you have an 80 watt panel that puts out 4.5 amps, you should have at least a 50 amp hour battery.



There's a LOT more involved, but that's the bare basics
This.

This is the inside of a home-made power box that usually rides in our box trailer for lights, chargers, etc.
http://i51.photobucket.com/albums/f360/quake316/made%20items/DSCN0833.jpg

Voltage from the panels comes in to the silver connector (on the left in the pic), to the charge controller, then to the batteries and the outlet ports on the right in the pic.

Outside (right side), three normal lighter-type outlets provide generic power outlets, and a streamlight strion charger base is hardwired in to provide an always-charged flashlight.
http://i51.photobucket.com/albums/f360/quake316/made%20items/DSCN0829.jpg


Battery cost will be an issue that will vary greatly, and it's worth getting creative with them. These pics are old, from when I first made the box; probably 2005 or so. Since then I've had to replace the batteries once - they're in a very hostile environment; a metal enclosed box trailer that gets well into the 130's-140's in the summer and freezing in the winter - so a shortened 4-5 year lifespan is all I'm likely to get no matter what I try. One thing I DID do, was to use different batteries the second go-round. The original two 18-ah batteries provided 36ah of 12vdc power, and cost me (wholesale) around $58 apiece. Instead, I replaced them with four 7ah batteries that cost $13 each. Those provide slightly less capacity (28ah vs the original 36ah) but total cost is only $52 instead of $116. Put another way, using a larger quantity of smaller batteries dropped my storage cost from $3.22 per ah, down to $1.86 per ah; more than a 40% cost reduction, in the one part of the system that's going to have to be repeatedly replaced.

When I built it, I knew about what power capacity I wanted, and bought the two batteries that got me that the simplest way possible while still fitting in a given space. I'm very glad I actually took the time to think it thru on the second set - any time a person can reduce maintenance cost by almost half, that's a good thing.

poodleshooter1
08-18-2011, 13:52
What about wind power? Where I live the sun is rarely seen, so wind power might be a better alternative and one that you have not considered.

Bolster
08-19-2011, 12:34
To answer your question: No, nobody has a complete list needed, because you are looking for a custom solution (and other than your basic 12v solar trickle charger, almost all solar IS a custom solution). As has been posted, you work backwards from your energy needs, and build around that.

Solar is not an "off the shelf" sort of thing. You have to load a lot of arcane knowledge in your head, do calculations, engineer it, and only then do you know what you should buy and how much. Solar is very "chicken or egg" type of stuff. It's like trying to solve an algebra problem where most of the variables are unknown, so a lot of guessing goes into the equation. Who can answer, with confidence, the question: "How much energy do you need?" Yet that's where all the calculations start. So you take your best guess at a number and go from there.

Small subsistance style cabins and small, frugal homes may work on 450-500 watt systems (usually 3x150w panels), so there's a start. A 450 watt cabin can make do with maybe 4 x 350 amp hour batteries. (An off-grid home needs maybe 1200-3800 watt systems to be comfortable. )

Your energy needs are small until you get to the refrigerator, then they balloon in size. I have a friend who has a solar powered sailboat (common these days) and the fridge was his biggest energy hog by far. He had to toss it, and drink wine instead of beer.

So the place for you to start is likely a book on going solar, of which there are many in libraries. Libraries LOVE these sorts of "green" books (pushing the secular religion of environmentalism) so pretty much any library will be well stocked on this topic.

I would like to build a small solar PV system, but am waiting to see if Obama gets voted out first. I don't want to become a statistic that props up Obama, as in, "Look at all these people who went solar under Obama." So I plan to buy late 2012 or early 2013. Call it "passive solar resistance" if you will.

Syclone538
08-19-2011, 13:43
What do you guys think about something like this for a cheap way to get started?

15 Watt Solar 12V Battery Charger Kit with 7 Amp Charge Controller
$100

http://www.tractorsupply.com/generators-accessories/solar-energy-systems/15-watt-solar-12v-battery-charger-kit-with-7-amp-charge-controller-8500020?ddkey=http%3AClickInfo&evtype=CpgnClick&intv_id=15001&mpe_id=12075&cm_cr=No%20Campaign-_-Web%20Activity-_-Cross%20Sell%20Up%20Sell-_-ProductDetail_Espot1-_-15%20Watt%20Solar%2012V%20Battery%20Charger%20Kit%20with%207%20Amp%20Charge%20Controller

MIJoe
08-20-2011, 07:08
Thanks for all comments.
Need to do my homework on solar power.
Joe

quake
08-20-2011, 07:09
That tsc unit seems like an ok deal - not great or terrible either one. Looks like it doesn't have a battery with it, so you'd have to buy that separate or else use this solely for charging batteries you already do have; car batteries, etc.

Carry16
08-20-2011, 10:08
deleted

Aceman
08-20-2011, 10:49
Run a fridge? Heck - I don't have solar for my iPhone yet!

Great idea though. Way better than a generator IMO.

kirgi08
08-20-2011, 16:37
What about wind power? Where I live the sun is rarely seen, so wind power might be a better alternative and one that you have not considered.

You lose a lot of juice in line transmission,the farther the batts are away from the source ect.'08.

LG-1 can answer this better than I.

emt1581
08-24-2011, 23:13
Around here it is rarely sunny AND windy but is usually one or the other.

What I'd like to do is create a system that will feed a common battery bank but, either simultaneously, automatically select one over the other, or can manually be switched from wind to solar power.

No clue how to tie both together but the concept seems valid in theory. I figure for $500- $1000 I can have a few car batteries charged year round for some minimal power should there be an outage.

It's interesting that the tractor supply kit was given a so-so rating. And I'm not sure if it is a better all-around kit or what. But when I made mention of the Harbor Freight kit (which is three times more powerful for 2 times the price) I damn near got my head bit off for even considering such a POS.

I'm not sure how many watts I should be looking for from a wind turbine and/or solar panels to keep 2-4 12v batteries charged but, as mentioned, from what I've learned a LOT of this stuff is a case by case issue and not cookie cutter in the least except for a few general components that most systems have.

Good luck and let us know what you decide on. :)

BTW... Quake...every time I see that box I drool... I want one badly!!

-Emt1581

Bolster
08-25-2011, 08:45
Around here it is rarely sunny AND windy but is usually one or the other...

Having both PV and a windmill is highly recommended, for the very reason you state. Chances are one will work when the other doesn't. No switching needed, they feed into the same bank of batteries. You should be thinking in terms of more than one battery, you have decisions to make whether you go 12, 24 or 48 volt...as has been said, all depends on what you intend to use it for, and how far you plan to run the wires (the more volts the longer distance you can run the wires...a wind turbine basically requires higher voltage than 12v, due to length of line run). Your panels always need to output MORE than the battery voltage. So for a 12V system your panels should be giving you maybe 16v.

What you need are the worksheets in the back of Rex Ewing's book, Power with Nature. Maybe I can scan and send to ya.

In the meantime here are some rules of thumb:

- My friend's sailboat, powering radios, lights, navgear, computer, fan, and sometimes a peltier cooler: 180 watts.
- Often recommended for a 'survivalist' cabin: 450 watts. Could probably run the above and a TV and/or small fridge and/or toaster oven.
- An offgrid house with all the amenities: 3000 watts or more.

Since solar panels often come 150w each (at $200-$500 ea), I am considering a 1x150 expandable to a 2-3x150 system running 12 volt, as a "backup" electrical system for running LED lights, recharging radios and batteries, running laptops during outages. Will require probably 2-4 100 amp hour 12v batteries, $200 a pop.

So for a minimalist PV backup system I'll probably be into it for a $grand$ when it's all said and done.

emt1581
08-25-2011, 08:55
Having both PV and a windmill is highly recommended, for the very reason you state. Chances are one will work when the other doesn't. No switching needed, they feed into the same bank of batteries. You should be thinking in terms of more than one battery, you have decisions to make whether you go 12, 24 or 48 volt...as has been said, all depends on what you intend to use it for, and how far you plan to run the wires (the more volts the longer distance you can run the wires).

What you need are the worksheets in the back of Rex Ewing's book, Power with Nature. Maybe I can scan and post for ya.

I was thinking, why not put the battery bank in a box directly under the wind turbine? So long as I can seal it from rain and snow yet allow for some gas to escape it should work...eventually it'll rot and/or rust though.

I'm not sure what the difference would be between 12, 24, and 48 volts in terms of running appliances or connecting to outlets. :dunno:

Those pages would probably be a big help! Thanks

BTW, I've been watching this guy's videos for a while now... pretty impressive IMO.

http://www.youtube.com/watch?v=ji7cuASm3ds&feature=related

-Emt1581

Bolster
08-25-2011, 09:48
EMT, setting up solar is complicated, so I can't urge you enough to read before you start designing a system in your head. There are very specific rules on battery placement (warm batteries are happier than cold ones, etc), guidelines for what voltage you want, etc, but I can't type it all out here, it's too much, and it's all sitting in a book at your library. Go to the library, check out a book on solar, read it. Don't rely on a few webpages or a webvideo for this one, it's complex enough you need a book. I'll see if I can scan some pages for ya, to get you started. PM incoming.

RED64CJ5
08-27-2011, 07:11
What do you guys think about something like this for a cheap way to get started?

15 Watt Solar 12V Battery Charger Kit with 7 Amp Charge Controller
$100

http://www.tractorsupply.com/generators-accessories/solar-energy-systems/15-watt-solar-12v-battery-charger-kit-with-7-amp-charge-controller-8500020?ddkey=http%3AClickInfo&evtype=CpgnClick&intv_id=15001&mpe_id=12075&cm_cr=No%20Campaign-_-Web%20Activity-_-Cross%20Sell%20Up%20Sell-_-ProductDetail_Espot1-_-15%20Watt%20Solar%2012V%20Battery%20Charger%20Kit%20with%207%20Amp%20Charge%20Controller

These TSC units work fine (I have two) but they have a much shorter lifespan than better panels. Expect 5-7 years out of them versus 20 years on a better quality panel. The TSC kit is actually a good deal when you factor in a decent charge controller. Harbor Freight carries some models but TSC's the most attractive. I'm using this same 15w kit in a semi-permanent installation right now to supply 12v lighting to my horse barn.

filthy infidel
08-27-2011, 07:57
I found some panels on sale and built a kit that would work for a survivalist, but is used as a tool at home. Two 15 watt panels with a charge controller filling a deep cycle battery. The battery powers a 3500 watt inverter via bastardized heavy guage jumper cable wire. I use it to power a variety of tools in the garage, it nicely powers my 1/2 hp rainwater pump to water the yard/garden via rainwater barrels.

quake
08-27-2011, 08:47
... Quake...every time I see that box I drool... I want one badly!!

-Emt1581

For the price of a quarter-sheet of plywood, some screws & hardware, some batteries, a charge-controller and a couple 10-watt attic-vent solar panels from Lowe's and a couple hours' labor, it too can be yours....



{Billy Mays voice [on]:} But wait! There's more!!! ;)

The first, smaller one I made, inside a small toolbox. Just a single 12-volt outlet with a rubber dustcover, down on the righthand side in the pic:
http://i51.photobucket.com/albums/f360/quake316/powerbox1-21-060032edited.jpg

Hard to see, but black velcro tabs on the lid mate up to velcro tabs on a simple 12volt fluorescent light. Very handy for portable area light when working on things at night:
http://i51.photobucket.com/albums/f360/quake316/PowerBox1-21-060062edited.jpg

Charged by three small deer-feeder solar panels; wired in parallel to keep it at 12 volts. Used a simple 4-wire vehicle-trailer connector for the wiring - three positives and a shared negative. This is the back side of the box, and here as well, velcro on the back of the box mates up with velcro on the backs of the panels to hold them in place:
http://i51.photobucket.com/albums/f360/quake316/PowerBox1-21-060042edited.jpg

Inside - a single 7ah battery, the trailer connector harness, and solar panels (held in place with velcro straps). Inline auto-type fuse (on battery positive) protects things. The white plug is a standard 120-to-12volt plug-in transformer which goes into a small charger power supply in the blue box, which then goes to the battery; allowing charging off standard house current:
http://i51.photobucket.com/albums/f360/quake316/PowerBox1-21-060092edited.jpg

Misc stuff carried in the box. Generic 12volt power cords, phone charging cord, extra fuses, etc. Power cord with small jumper-cable type clamps lets the box be used to jump start a 4-wheeler, lawnmower, etc. (Don't expect it would do a fullsize vehicle; never tried it.) Also a small 120-volt inverter, but the output on it is very limited. Really only good for small device chargers & such that we may not have a 12volt cord for:
http://i51.photobucket.com/albums/f360/quake316/PowerBox1-21-060102edited.jpg


Seriously, just cobble one up some time. You'll likely enjoy it and you'll find all kinds of uses for it once you have it.

emt1581
08-27-2011, 08:51
I had no idea my local township had such strict directives on these...

Small wind-energy systems shall comply with the following regulations:
A.

All small wind-energy systems shall be enclosed by a fence at least six feet in height, which is located at least five feet from the base of such small wind-energy system. However, no fence is required for a monopole structure.
B.

No small wind-energy system, vane, sail or rotor blade to pass within 15 feet of the ground.
C.

All electrical wiring leading from a small wind-energy system shall be located underground.
D.

No small wind-energy systems shall be permitted within a front yard.
E.

The height of a small wind-energy systems (including highest elevation of blades) shall not exceed 130 feet.
F.

A small wind-energy system shall be set back from a property line or aboveground utility line a distance greater than its overall height, including blades, or the minimum yard requirement, whichever is greater. It is noted, however, that anchors for guy wires that may be needed to hold a small wind-energy system tower vertical shall be located no closer than 10 feet to any property line.
G.

Small wind-energy systems shall comply with Federal Aviation Administration (FAA) regulations and the design engineer shall certify that the applicant's proposal will not violate any of these regulations.
H.

If guy wires are utilized to stabilize the location of a small wind-energy system tower, these guy wires shall be protected and/or labeled in such a way as to provide "notice" to persons who may be walking, riding bikes or otherwise passing near the guy wires.
I.

All components of a small wind-energy system shall be designed by one or more professional engineers and all design drawings and calculations shall be supplied to the Township as part of the building and electrical permit application procedure. The design and construction of electrical generation, storage and supply equipment shall conform to appropriate provisions of the National Electric Code. The design and construction of any tower utilized for the purposes of supporting a small wind-energy system shall be conformed to the appropriate provisions of the International Building Code Section 1609, as provided for the exception by utilizing the Structural Code TIA/EIA-222, latest revision as published by the American National Standard Institute (ANSI). The structural professional engineer shall be responsible for the study of subsoil and geologic conditions to provide documented information on which to base the design of the foundation of the structures proposed. A report of this soil and geologic information shall be provided as part of the permit applications. The design of any wind turbine shall address reasonably foreseeable mechanical and electrical damage to the structure, the turbine or electrical system of the principal structure due to high wind, lightning and/or power company outages.
J.

Any tower utilized for the support of a small wind-energy system, turbine and blade shall be finished and/or painted with a nonreflective color or finish of natural metal or white, light gray or light blue, except that blades may be dark gray or black.
K.

Small wind-energy systems shall not be lighted or illuminated in any way, unless an aircraft warning light is required by FAA regulations. Documentation of this requirement would need to be provided as part of the permit application. This prohibition against lighting includes a prohibition of any lighting that would be directed toward or aimed at any portion of the structure and/or small wind-energy system.
L.

No portion of the small wind-energy system shall be utilized for signage or advertising regardless of the zoning district in which the system is constructed.
M.

The owner of a small wind-energy system shall remove all components of the system, including the support structure when the system does not operate, or is not used to generate electricity, for more than one year, for any reason.


...I was thinking of pulling out the PA Dutch looking weather vane on my roof and then sticking the pole with the wind turbine in it's place and run the wiring right down into my garage. Seems like it'd meet all the requirements of my township except for the underground wiring part. One of the guys at my fire station is on the township board so I'll run it by him first.

Just figured I'd share...MAKE SURE you check with your local communities rules and regs before putting one up!!

-Emt1581

Big Bird
08-27-2011, 09:03
I've been running a chicken coop door opener on a timer for for two years now using a dedicated 12 volt battery and solar panel charger I got from Cabelas. Of course I doubt it draw 2 amps when the motor kicks in for 20 seconds twice a day...

It really depends on how much 'tricity you need, and for how long. Keep in mind that solar power costs about ten times per watt over what you get off the grid and that's an optimized number. If you are looking to generate power in emergencies you might be better off with a gas powered generator.

DoctaGlockta
08-28-2011, 13:27
I'm thinking of getting this:

http://www.amazon.com/Instapark%C2%AE-Mono-crystalline-Solar-charge-controller/dp/B004FOGL0K/ref=pd_ybh_10?pf_rd_p=280800601&pf_rd_s=center-2&pf_rd_t=1501&pf_rd_i=ybh&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=17F0HVRQM64PKAQGCYFQ

Will charge a 12v deep cell. Just to get my feet wet and see how it goes.

Bolster
08-28-2011, 13:47
I'm thinking of getting this:

http://www.amazon.com/Instapark%C2%AE-Mono-crystalline-Solar-charge-controller/dp/B004FOGL0K/ref=pd_ybh_10?pf_rd_p=280800601&pf_rd_s=center-2&pf_rd_t=1501&pf_rd_i=ybh&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=17F0HVRQM64PKAQGCYFQ

Will charge a 12v deep cell. Just to get my feet wet and see how it goes.

30W for $140? Ouch! Granted you get the controller thrown in (is it a good one? Reviews at Amazon not so good...) but I recollect seeing 150W panels starting around $200 (http://www.sunelec.com/), with 5x the output. Charge controllers start around $20.

@ quake: Pretty cool box there. Envious, I am.