Solar power for the “outback” (Please share freely)

Discussion in 'Energy & Electricity' started by horology, May 12, 2010.

  1. horology

    horology Active Member

    I have gotten many questions on how we did solar power so cheap. First thing to consider is how much power you really need. Many people go overboard on what they think they need. I know that I’ll be working this out again soon as we have a new family in our community* (and room for one more).

    On all electrical devices there is a UL tag. This tag is where you can find the power consumption of the device. For example, my laptop uses 60 watts and the satellite internet modem uses 150 watts. I mention these because it’s what we use the most. We also use DC fluorescent lights. These provide lots of light and use very little power (15 watts and 35 watts). This type of lighting can be had from a RV parts supplier or on eBay. With a little math you can see that at any one time the most power we’ll be using is 265 watts. Not much, is it?

    We have a 205 watt high efficiency solar panel that we got it from a company called This panel cost about $500 and is really great.

    Now you’ll need batteries to store the power. Wallyfart sells RV/Marine deep cell batteries for $70-$75. These are very good because they are built to be drawn down and recharged repeatedly. But there is another way for those who like to tinker with things. Battery reconditioning is a simple process of removing the minerals that cause the premature death of batteries. (SEE BELOW HOW TO RESTORE BATTERIES)
    We use 6 of these RV/Marine batteries and unless it’s been overcast for many days, we never run out of power. We use the power to watch videos on our laptop well into the night.

    You’ll also need a DC to AC inverter to have “house current”. We use a 750 watt inverter and this does everything we need it to do.

    When hooking up all electrical devices, the first thing to consider is that DC looses power the longer the run of wire is, so do your best to keep all these components close together and use heavy gauge wire. 8 or 10 gauge copper wire works best.

    Restoring Batteries:

    FIRST THING IS YOU MUST BE CAREFUL!!! Battery acid can burn you!!!!! You’ll need Rubber gloves and eye protection!!!! No exceptions!!!

    Things needed:
    Rubber gloves
    Eye Protection
    Baking soda
    EDTA (most health food stores carry this)
    Distilled Water
    Battery Charger or solar panel
    Battery acid (most auto parts stores will have this)

    First remove the old battery acid from the battery by pouring the acid into a plastic bucket that has 1 cup of baking soda in it. Then fill the battery with distilled water, close the caps and give it a good shake. Then pour the contents of the battery in to the bucket.
    Now your ready to chelate the battery. Mix one tablespoon of EDTA (can be had from any good health food store – open the capsules if that’s the only way you can get it) into one gallon of distilled water, then fill the battery with the solution.

    Now you’re ready to put the battery on a slow, 24 hour charge. With the overnight charging done, check the battery voltage. If the battery does not come up to 12.5 volts at this point, putting the new battery acid in to the battery is a waist of time. If this is the case, the battery is beyond saving. If it does come up to 12.5 volts, empty the contents of the battery in to the bucket and replace it with battery acid. Then give it another 24 hour slow charge.

    My track record for doing this is 9 came up to spec and one did not.
    You’ll notice that most car repair shops have a place where they put old “dead” batteries. These are worth $8 each to them for a core charge.
    Let’s say you buy 10 of these dead batteries and pay $8 each for them.
    Cost of distilled water $1 per battery
    Cost of Battery acid $2 per battery
    Cost of EDTA $10 for a few dozen batteries
    Total Cost for 10 batteries and supplies $84
    Recondition 10 and get 8 up to spec and your cost per battery is around $10, not $75.

    *Visit (Don’t just WATCH, REPAIR the WORLD)
    and survivalistnm : Survivalist New Mexico
  2. NaeKid

    NaeKid YourAdministrator, eh?

    Very nice writeup!!!

    Have you considered adding a wind generator to your system or is there enough sun year 'round to keep the batteries alive?

  3. horology

    horology Active Member

    Solar Power

    Actually, here in New Mexico, we have almost enough sun to not have to depend on even the small generator we have standing by for a series of cloudy days in a row.

    Supplementing with wind power would depend on where you live. You would need 30 mph sustained wind to be worthwhile, and if you're in a canyon or valley or have other buildings around, that can be tough. Good in certain places, not in others.

    *Visit (Don’t just WATCH -- REPAIR the WORLD)
    and survivalistnm : Survivalist New Mexico
    Last edited by a moderator: May 12, 2010
  4. eveowitz

    eveowitz New Member

    I just purchased a cabin, for a friend to live in. it is a 12 by 32 and unfinished. i plan to finish the inside with all things that make life easier to us all but am troubled by power. i am thinking about your solar power but i am a woman and also troubled by the level of knolage for such things. can you break it down for me even more? Wireing and such? please help?
  5. gypsysue

    gypsysue The wanderer

    It's possible to go even lower on the watts. My husband and I each have laptops, one takes 35 watts, the other takes 50. We use not only the compact flourescent light bulbs but also have several of the new LED light bulbs that perform even better than CFLs and use even fewer watts. We got rid of our old TV and bought a thin-screen LCD TV, 20", which takes 53 watts. No Satelite or cable, but the DVD player takes 14 watts.

    The Wireless DSL modem takes 6 watts. Our 10 cubic foot frost-free fridge takes 147. (Everyone said "go propane" on the fridge, but this way it's free, and we run it from about the first of March till the end of October, and shut it off and use nature's fridge over the winter). The Nesco dehydrator takes 500 watts so only gets used on sunny summer days.

    We have 9 solar panels with a total of 1, 105 watts. Battery bank of 7 Wallyworld deep cycle batteries. A 1,000 watt inverter from Costco, and an 800 watt trace inverter bought used from a neighbor who got a bigger one. We use two charge controllers.

    We have an Air-X 400 watt wind turbine with built-in charge controller. It's more of a novelty than anything. The solar was a much better investment, as we're sheltered back in the mountains and the wind direction isn't consistant or steady.

    We started with one panel we acquired in a barter arrangement, bought another one the next year, then kept adding over the last 5 years.

    We're very happy with our solar power, even with the short daylight hours in winter waaaayyyy up here in Montana near the Canadian border.
  6. NaeKid

    NaeKid YourAdministrator, eh?

    GypsySue - are you running 9 panels at 120 watt each to run your cabin? Have you considered running CATerpiller batteries at all? I have a friend who has a connection that can get me an unlimited supply of CAT batteries for next to nothing (well, half of what a normal RV DeepCycle battery goes for).

    What guage of wiring are you running between the solar and batteries?

    Are you running a fuse-panel from the batteries to the accessories or are you using inline fuses.

    eveowitz - I wired up my tent-trailer with solar and as long as you don't cross the power (negative direct to positive) you are good to go for the wiring. On my trailer, I am using 4-guage wire from the panel to the charge-controller to the battery / fuse panel. I am running an 80-watt panel to dual 6-volt RV batteries and - so far - so good.
  7. gypsysue

    gypsysue The wanderer

    naekid, I'll answer what I can. MMM is out fishing again...

    Our solar panels are: one 64-watt, one 110-watt, three 130 watt, and four 135 watt. The first 5 are on one tower, the other 4 panels are on a separate tower.

    We used 8 gauge wire. The fuses are inline.

    I'd say the CAT batteries are a good idea! We've rolled around ideas such as 6-volt golf cart batteries. Don't think we could afford Submarine batteries! (lol) Maybe we can talk more about those CAT batteries. Sounds like something that would have more amp hours, and maybe a longer life?
  8. NaeKid

    NaeKid YourAdministrator, eh?

    Here is a link to their .PDF of their industrial batteries: Equipment.pdf

    I used to work for an auto-auction as the "lead-driver" - organizing the drivers, helping to get the vehicles running to take them through the auction-bays, etc. We had two "starter-trucks" that kept a pair of the biggest CAT batteries ever made strapped into the back of the trucks. Those batteries were charged the day before and would start dead vehicles all day long. Yes, the trucks alternator would top-up the batteries, but, minimally due to the long idle-time.
  9. JeepHammer

    JeepHammer Well-Known Member

    I have VERY little wind where I live, but I have two home made wind generators.
    Since I don't have running water on my land, wind is a 'Backup' to the backup.

    We usually have wind on bad weather days, when the sun isn't shinning, and I have wind at night many times.

    I've found the small wind generators are a VERY GOOD way to 'Trickle Charge' the battery bank in supplement to the solar panels.
    They produce a very low charge, they produce when the weather is bad, and they 'Top Off' or 'Finish Charge' my battery banks very well.

    Home built units are very inexpensive, they produce during inclement weather, and they don't require a lot of maintenance, so I find a wind unit pretty handy.
    If someone had moving water in their area, that would be a much better way to go...
  10. JeepHammer

    JeepHammer Well-Known Member

    I have VERY little wind where I live, but I have two home made wind generators.
    Since I don't have running water on my land, wind is a 'Backup' to the backup.

    We usually have wind on bad weather days, when the sun isn't shinning, and I have wind at night many times.

    I've found the small wind generators are a VERY GOOD way to 'Trickle Charge' the battery bank in supplement to the solar panels.
    They produce a very low charge, they produce when the weather is bad, and they 'Top Off' or 'Finish Charge' my battery banks very well.

    Home built units are very inexpensive, they produce during inclement weather, and they don't require a lot of maintenance, so I find a wind unit pretty handy.
    If someone had moving water in their area, that would be a much better way to go...

    I've been doing 'Alternative Energy' projects before it was called 'Alternative Energy'...
    And I owned a starter/alternator/battery/engine electrics business for about 10 years before I sold it,
    So I know a thing or two about rebuilding generators, batteries, ect.

    The one thing NOT pointed out earlier is the 'Scale' that builds up on the battery plates comes from improper additives to the batteries.
    DISTILLED WATER is the ONLY thing you should ever add to the batteries!
    If you don't put in 'Hard' water, then there isn't any particles to build up on the plates,
    And the only thing you have to deal with is 'Sulfidation',
    The electrolyte actually attacking the plate material, and that is usually pretty easily scaled off with proper charing and De-sulfidation cycling.


    Some things have been pointed out, but some others, like safety concerns, should be addressed.

    In my particular situation,
    I have 12 solar panels producing for two battery banks.
    The battery banks are in VEHICLES, this makes my batteries do more work for me.
    With an inverter mounted in the vehicles, (Golf Cart and home converted S-15 Pick Up),
    I use an extension cord for ELECTRIC chain saws, electric drill motors, saws, ect.
    Common 115 volt tools work great, saving me money on tools,
    And I don't have to store stuff like gasoline that goes 'Bad' very quickly.

    These 'Maintenance' vehicles allow me to manage the farm chores without having a ton of gas engine tools, the batteries in the vehicles support the farm when not in use, and provide me quite, reliable, non-petroleum based transportation and load carrying capacity.

    I have my 'Power House' at the solar array.
    It's away from my house, and houses the inverters, charge controllers, well/pump, ect.

    The reason for having the inverters, ect. away from the house is simple,
    I can't easily provide an adequate fire control and wire shielding in the house,
    And I don't need the corrosive gases and dangers of the battery/wiring in the home.

    In the 'Power House', where my pressure/water tanks are,
    I can provide sprinkler fire protection without flooding the house,
    I can provide proper 'Industrial' type wiring protection,
    I can keep the battery banks close to the DC power production, cutting losses,
    I can convert my produced power to AC, which pushes through wiring MUCH better,
    And that keeps the house on 115 Volt AC power, so I don't need any special appliances in the home, and that keeps the cost down for appliances in the home, standard wiring, which is MUCH cheaper, ect.

    The 'Power House' with well/pump allows me to have a separate insurance rider for 100% replacement costs in the event something happens,
    Something you CAN NOT do in the house in my state. Prorated for age or nothing in this state if it's in the home, plus your fire insurance goes WAY up...

    Since the batteries/inverters have triggered the sprinklers twice, (Spiders one time, false trigger the second time, gases corroded the smoke detector and set things off) there were NO FLOODS in the house!


    If you go with large STATIONARY battery banks,
    Then go with FORK TRUCK BATTERIES.

    Some guys talk about 'Bull Dozer' batteries, which are actually BCI Group Size 8-D or 4-D,
    Some of the common fork truck batteries will have 40 or 50 times the storage capacity of two to four of the 8-D batteries.
    (BCI, Battery Council International,
    Battery Council International - Wikipedia, the free encyclopedia
    Car battery - Wikipedia, the free encyclopedia
    Battery Recycling

    Fork Truck or Industrial Battery Powered Equipment, like underground mining, will provide you with batteries that weigh TONS in some cases, and make for a MUCH easier way to connect cells (Already done, most large batteries are 24, 36, 48 volts) and make for a much more compact, higher output standby power storage systems.

    Vehicle batteries, like 'Golf Cart' batteries, are a fair way to do things, but they take a lot of external wiring, need constant maintenance to keep terminals/wiring clean, need rotation frequently to keep the 'Outside' or 'End' batteries from over charing, and the 'Inside' cells from under charging, ect.

    If the batteries are smaller (under 100 pounds most times), then I prefer to keep them 'Mobile',
    In vehicles so they do DOUBLE DUTY instead of just sitting in a battery box somewhere waiting to go bad... Being over charged, and generally degrading while sitting still...


    Now, before the 'Hate Mail' starts,
    I'm not trying to sell this as a 'Home Game',
    If you don't agree with me, then simply don't do it!

    I've been doing this for a long time, and I find no issues with using the batteries for vehicles and adding battery capacity to my system at night when I'm not working.
    Since I don't drive but one vehicle at a time, there is ALWAYS one vehicle charging/providing current for the inverters for farm/house,
    And most of the time, BOTH vehicles are plugged in to the system either charging in the daytime, or running the inverters at night.

    These make a MUCH better way to support my 48 volt fork truck batteries that sit in one place running the house full time.
    (Which by the way, were FREE haul offs from a plant closing when the production moved off shore),
    And I haven't had a minute of issues with the system in 6 years...

    If you are going to do this, save yourself THOUSANDS OF DOLLARS, think MODULAR and SYSTEMS instead of 'Production' and 'Storage'...

    My PV cells are mounted on an old house trailer frame. They are MOBILE if I need to move them.
    The racks are EXPANDABLE, I can add up to 48 panels with no issues, and still have my two 4'x8' solar THERMAL (hot water) panels to preheat water for the house/garage.

    The 'Power House' is a 'Yard Barn' on skids, so it can be moved in the event I want to place it somewhere else.

    My well head is protected that way, And I have a hand pump if everything else goes south, I can pump water if needed. It's a SYSTEM, not a bunch of components that loosely work together.

    We DO have two panels on the house, smaller, older panels I used before we built the system at the farm.
    They do jobs like running the pump for the hot tub, which is also solar thermal heated.
    No pump switches, when the sun goes down, no solar to heat the water, so the pump shuts off at night...
    The same panels supply pump current for our water catchment tanks we use to water the garden, live stock, ect.
    No cost for pumping water out of the well, no filtering for garden or live stock, just rain catchment and a pump to get it out. Since we only work in the daylight most times, there isn't an issue with having water pressure at night.