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Solar Back Up Power
#1
Talk to me about Solar Power!



-I have an unlimited access to Gel-cell 1250CCA batteries here at work (I work with trucks).



-I can get a 400 watt Cobra converter for $25.00 as well. (I'll get two) That Cobra converter has a low voltage cut-off. Do I want that for this application? Gel-cells can be run dead & recharged repeatedly.



-What wattage solar panel do I need?



-What else do I need? I assume that's it.



In the event I lose the Generator or civil unrest would make running it unwise I'd like a Solar option.



Thanks in Advance! <img src='http://www.hoodswoods.net/IVB/public/style_emoticons/<#EMO_DIR#>/thumbsup.gif' class='bbc_emoticon' alt=':thumbsup:' />



RR
We have the right to our opinion but not to the facts.
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#2
First, "CCA's" mean nothing in the world of back up power. Most vehicle batteies are down right lousey at supplying power. Take a 850 CCA battery out on a lake with a trolling motor hooked to the boat and you are lucky to get 1/2 hour of use. Now take that same boat and trolling motor and hook it up to a "deep cycle" battery and you'll run around the lake for hours. What you need to look at in a battery is it's AMP HOURS. A deep clycle battery usually has about 100 amp hours. If you don't see amp hour's listed for the battery it's crap and not worth using. As stated, deep cycle marine batteries, golf cart batteries and batteries for electric lifts are the best options.



Second, solar is downright lousy too. To get much wattage you need many many large, expensive panels.



The 400 watt inverters will run a radio and not much else. That's only 3.33 amps. Won't even run most furnaces let alone a refrigerator. That's only 4 - 100 watt light bulbs if you max it out. Most house loads are in the 50-100 amp range.



Now go back to the batteries and panels for a sec. Say you have 2 - 100 AH batteries. If you take a 12 volt 15 watt panel it will charge a battery at a rate of about 1.25 amp per hour. To charge a 100AH battery it will take 89 hours of sun to recharge. At the same time your refrigerator draws about 5-6 amps for 120 volts. That transfers to between 600-720 watts. 600 watts divided by 12 volts equals 50 amps.



In other words, that 100 amp battery that takes 80 hours of SUNLIGHT to charge will be dead in 2 hours of run-time on your refrigerator. Sound promising. NOT!



For a back up system to work you need at least 3000 watts of power for furnace, refer a TV and a couple lights. That means you need 3 (actually 2.5 but who ever heard of 1/2 a battery) 100AH batteries to run your house for 1 hour. Want to run your house for 4 hours you need 10 batteries. For 8 hours 20 batteries and for 24 hours 60 batteries. That is if they aren't being charged. But over all you need 3000watts constantly. That's can be panels, wind turbine or generator.



Check this: [url="http://www.mrsolar.com/page/MSOS/CTGY/remote"]http://www.mrsolar.com/page/MSOS/CTGY/remote[/url]



Note that the "480 watt system" at the bottom is using 6 batteries and 6 - 80 watt solar panels. This MAY BE barely big enough and the smaller systems just won't cut it IMO. If the sun shines 12 hours a day you will get about 6000 TOTAL watts of power PER DAY, MAXIMUM. Your refrigerator alone will use 1/2 of that power. It's only $4350.



Still sound viable?





Solar suck, think wind.
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#3
[quote name='C_Brice' post='365778' date='May 12 2009, 09:30 AM']Solar suck, think wind.[/quote]



solar's nice on the move.



vec
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#4
But worthless for minimal power backup?



I didn't want to run the house. I was thinking small items.
We have the right to our opinion but not to the facts.
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#5
CB,



Thanks.. I think I just got a bit of an edu-ma-kation....
I Hear Voices.....And They Don't Like You.



"Further, I propose that this "Moment of Misery" be hence-to-forth be referred to as "Moment of Misery for Misanthropic Yammering", or "MOMMY"!" ~ DDennis2



(what an effing moron. - i feel such pity now for his lovely wife and intelligent children - and maybe even for his food-quality dawg, nick-named "Spicy" sez i.)
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#6
CB, you seem to know alot about this stuff, so what do you recommend for a starter wind system? ( not intended to run a house all day)
Self proclaimed Zombie Hunter "Shoot'em in the head and they stay dead."

Aesop's fable #373 the Ant and the Grasshopper

Book of Proverbs 6:6-9 "Go to the ant, you sluggard! Consider her ways and be wise, which having no captain, overseer or ruler, provides her supplies in the summer, and gathers her food in the harvest. How long will you slumber, O sluggard!"
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#7
Roadracer, 1 deep cycle battery equates to about 1200 watts. You can run 1 - 100 watt light bulb for only 12 hours. 4 for 3 hours. etc. Like stated, it would take a $100 15 amp solar charger 80 hours to recharge it. At 12 hours a day for sunlight it would take 6.66 days to recharge a 100% dead battery. How does a grand total of 12 hours of 100watt artifical light sound spread out over 6.66 days? That means you could run that ONE light bulb for 1.8 hours per day and thats it. How's that for minimal? You would be better served to invest in a bunch of batteries, a 1200-1500 watt inverter and a battery charger for them and just keep the battery charged while you have power. A small, cheap solar system won't help much at all for back up power. Or just get a propane fired generator that is about 13,000 watts and a 100-500 gallon tank and call it good. Cost is about $4000.



Darthhamtaro, I've never actually installed a wind system but have researched the crud outta it and worked with a company on solar systems that also was doing wind. I also worked on all the buildings for a BIG wind farm (but didn't do the atcual towers), and run new underground cables to a BIG windmill for a school. Most wind AND solar systems I've seen aren't used for "back up" power. They hook them right to the grid and are used to reduce energy bills for the end user. Seems to me that wind power systems cost about $1.00 per watt. A 5,000 watt system is about $5000, 10000watt system is $10,000, etc. etc. I recommend making your own.



The key to back up power is batteries and reducing your load/consumption. You figure out how much you need to run your house and then size your battery bank for the length of time you need it to run. Say your house draws 2000 watts (very low) per hour all day. Thats 24,000 watts. Like I said, 1 battery is about 1200 watts so you need 20 batteries to run one day. Then you take into account your power source. The above mentioned 480 watt solar system supplies about 6000 watts. So you can reduce that battery pack from 20 to 15 (6000 watts devided by 1200 watts). So 15 batteries will last 1 day at 2000 watt per hour. 30 batteries will last 2 days. Etc Etc.



Back to the 480watt solar system. Like I said it's about 6000 watts or 6 kilo-watt-hours (KWH). Your power company may charge you $.10 per KWH so you save $.60 per day on an electric bill. That is about $18.00 per month. If you want to use that solar system for off grid living it equates to reducing your current electric bill down to $18/month. I dare someone to try that!. Like I said, reducing your demand is also key.
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#8
I checked here [url="http://www.bergey.com/"]http://www.bergey.com/[/url] for prices. A 1000watt wind turbine is about $2500. This supplies twice as much power as the solar system above and works even after dark as long as the wind is blowing. So it "may" provide up to 4 times the energy as the solar system for 1/2 the cost.



For off the grid living the 7.5KW unit should do but it's $23,500 plus tower and batteries. IIRC will last about 10 years with good maintenance. So that means your are looking at $3000 a year for electricity. I know I've seen similar set ups for $10,000 though.
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#9
problem with wind is that you need a constant 20 mph to make it work well, there are very few places in the usa that has this constant wind day in and day out. look at some of the wind maps of your area, you will be supprised at what you see as far as average wind velocity. the tower needs to be 30-50 ft tall to get over most trees and obstructions.

here is a map of average wind values for the didfferent states:

[url="http://www.windpoweringamerica.gov/wind_maps.asp"]http://www.windpoweringamerica.gov/wind_maps.asp[/url]



alex
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#10
I, too, would rather have wind than solar. It is far more economical.. and where we live it is not a problem to have enough wind to generate backup power. We could most likely get by running the whole house on wind if needed..



Solar for smaller items is great however. For example.. I have a solar/crank radio that never fails. I have a few solar lights that are pretty good. And we just got some solar "walkway" lights for an outside driveway/walkway. We only brought two of them for the moment ($4.00 a piece). But last week when we were without power for 18 hours (thanks to tornadoes) they provided enough light inside (these are removable from their bases and can be carried or set on a table/wall) to see where we were going and even read if you sit close enough. Going to get about 6-10 more of these.. I like them!



- Ben
Ben Tziyon



http://www.yhwhswordoffaith.com/WAS/Survival.htm

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You can live for 3 Minutes without Air...

For 3 Hours without Shelter...

For 3 Days without Water...

For 3 Weeks without Food...

But you can't live at all without Faith!
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#11
CB;



Either you have been around this stuff a bunch or you are a graduate of the MrSolar internet school............. Great description.



thanks.



Sawyer
Liberal: A Conservative that hasn't been mugged.



Oh, may I go a-wandering until the day I die;

Oh, may I always laugh and sing beneath GOD's clear blue sky. Friedrich-Wilhelm Moller



"We face the question whether a still higher standard of living is worth its costs in things natural, wild, and free."

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Just Rambling again......... Sawyer
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#12
[quote name='sawyer' post='366032' date='May 12 2009, 08:33 PM']CB;



Either you have been around this stuff a bunch or you are a graduate of the MrSolar internet school............. Great description.



thanks.



Sawyer[/quote]



All of the above Brother Sawyer! Between my experience as a Master Electrician, my experience's in the alternative energy feild, lot's of research and simple math via Ohm's Law. Glad I could be of help.



I'd like to point out that batteries are my weak point. Lot's of folks talk about batteries shouldn't drop below 80%. I don't know if the Amp hour rating is only to the 80% or for the entire range of the battery, Completly dead to completly charged. In other words, is the if you use 100AH is the battery at 80% or dead? Don't know myself.



CB
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#13
[quote name='Roadracer' post='365723' date='May 12 2009, 06:59 AM']Talk to me about Solar Power!



-I have an unlimited access to Gel-cell 1250CCA batteries here at work (I work with trucks).



-I can get a 400 watt Cobra converter for $25.00 as well. (I'll get two) That Cobra converter has a low voltage cut-off. Do I want that for this application? Gel-cells can be run dead & recharged repeatedly.



-What wattage solar panel do I need?



-What else do I need? I assume that's it.



In the event I lose the Generator or civil unrest would make running it unwise I'd like a Solar option.



Thanks in Advance! <img src='http://www.hoodswoods.net/IVB/public/style_emoticons/<#EMO_DIR#>/thumbsup.gif' class='bbc_emoticon' alt=':thumbsup:' />



RR[/quote]



Brother CBrice has given some good info. I suggest you do some more research to decide what you need and how to build it. First I'd suggest you go to the Backwoods Home Magazine site, backwoodshome.com, and read through Jeff Yago's articles on home power production. He goes into lots of detail about how to size your system to suit your needs, and covers batteries, too. He writes very clear and understandable articles, even I can follow his directions.

Your local library also has several books on alternative energy, too. With some research and some pencil and paper work, you can come up with a system that will do what you want. Don't lock yourself in to solar OR wind, use both if you can, and plan on a small generator, LP powered or gasoline or whatever, for Murphy proofing. Northern Tool has quite a bit of solar panels, wind generators and etc. in their catalog, as does Harbor Freight and other outlets, search the web for solar power, wind power or alternative energy.

I'm no electrician, but there is a world of info available that will let you do what you need to. Hope that helps.
Think direction first, then velocity.

“Let your gun accompany you on your walks, the heft will do you well and it will ward off evildoers.” Thomas Jefferson
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#14
I think people have a few wires crossed here. There's a big difference between emergency power and a full on off the grid system. I think RR is on the right track with the gell cells. I suggest 12 volt bulbs, fridges, etc and DC generators. Solar is a good back up if all else fails. At least you have some energy comming in.
Message of Insight and Unity 

We go into the wilderness to fulfill our hearts and empty our minds of life's garbage.
The gear we leave behind and the challenges we encounter, 
Are methods we use to cleanse our spirits.
Of Survivalists and Bushcrafters, Primitive Technologists too, we are one.........

It is the wilderness within, we strive for first and always.
Not everyone can have a cabin in the mountains.
The thread that connects us, is fine like silk and strong as steel.
Together, the song of the wilderness is the song we sing!

"And can I say something else?"
Bushcrafting is "doing what you want to do." 
Survival is "doing what you have to do"
Primitive Technology is about all of the above........

By TNRR aka "Survival Sully"
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#15
Could always think about using LEDs for lighting also.
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