Watts/Amps/Volts HELP!!

Discussion in 'Homesteading Questions' started by NikiandAlex, Mar 4, 2005.

  1. NikiandAlex

    NikiandAlex Member

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    Lynchburg, VA
    I want to get a solar power system going in my RV. I'm absolutly clueless and didn't know where to turn, so I thought someone with knowledge of electricity on this message board could help.
    I have a 28 ft RV, the manual says an outside power source is 115 Volts, the breaker box says 30 amps and at .11 cents/thing (?) we paid $50.00 over a months time when we camped at a campground. The RV packages are measured in watts and I don't know what to look for. Any advice??
     
  2. gspig

    gspig Well-Known Member

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    You will have to deal with an enormous number of issues. First does your RV have a DC circuit panel? If not then you are going to add an inverter to you shopping list. Next you will need to determine what appliances and lights you want to run off your solar system. Then you will need to find the volt and amp requirements for each of the devices. Wattage requirement is volt X amp. You will also have to build a battery bank. Batteries are rated in amphours, how many amps it can provide for an hour. Inverters are rated in watts, you will need this for all AC voltage appliances. You could have one for each appliance or one that will handle all your appliances.

    I don't know your RVing lifestyle. If you stay long periods and live out of your RV, maybe much less hassle to just plug in to the campground electricity. If you boondock or camp primative, the battery bank with solar recharge may work for you.
     

  3. jgbndaudio

    jgbndaudio Well-Known Member

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    New York
    Hello,
    Here's a good link to spend some time at, it has a lot of great info.
    http://www.masstech.org/cleanenergy/solar.htm

    I've been doing this stuff for a hobby for over 10 years and hope to somehow turn it in to a new career. Feel free to write me with more questions.
    Scotty


     
  4. NikiandAlex

    NikiandAlex Member

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    Jul 16, 2004
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    Lynchburg, VA
    We'll be living in it while we build our cabin, so let's say that I want to treat it like a normal house. Like say I buy a 100 watt RV solar system (haha), would that work? I've read all the info, but I just don't get it. Serves me right for stopping at Algebra II...damn peer pressure...lol
     
  5. rambler

    rambler Well-Known Member Supporter

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    If you are going to live in the RV on the site where you are building your new cabin, then plug your RV into the same power you will have on-site to build the cabin. Most building sites have electricty for building?

    Solar power is one of 3 things:

    1. Very, very meger power supplied

    2. Very, very expensive

    or

    3. Assembled from scrounged parts by someone who has deep understanding of electricty and is perhaps prone to fail & be put back together by the owner with more salvaged, scrounged, half-wore out parts - takes time to find & create


    You will not get tons of cheap solar power. That is not possible today.

    The 100watt system you mention will light one light bulb overnight for as long as the sun was shining that day. That is all the power you will get out of it. Or maybe you will get 10 cups of coffee from a coffee maker. Per day. But you will need to drink it in the dark - only enough power for one or the other.

    Can you tell us how many 'things' you used in a month from your RV bill? Divided by 30, that is how much power you will need to generate every day from a solar setup. From this _and_ the amount of sun in your location some can tell how many 100watt panels you will need to continue your lifestyle.

    11 cents a kwatt & $50 a month, would be 15 kwatts per day. So you would need 15 of those solar panels - assuming you have no clouds or anything. This is my guess, but I am pretty stupid on all this. My math could be _way_ off.

    --->Paul
     
  6. moopups

    moopups In Remembrance

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    Go into the archives until you find 'countryside', click there and scroll down to 'alternative energy', there are many informative articles there on this subject.
     
  7. JWH123

    JWH123 Well-Known Member

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    Location:
    USA
    OK. If you paid $50 for a month of power and you were charged 11 cents per kilowatt-hour, you used 454 kilowatt-hours (KWh). That is 50 divided by 0.11.
    Now there are 24 hours x 30 days in a month. That's 720 hours. Now we divide 454 kilowatt hours by 720 hours, and you get .631 kilowatts, average. That's 631 watts on average. Take six 100-watt bulbs and screw them in sockets, and turn them on. Leave them burning for an entire month, and you would use the same amount of electricity.

    If you consider one day's worth of use, take the 631 watts and multiply by 24 hours. you use 15,144 watt-hours in one day. Now assume you have 6 hours of usable sunlight in a day. To generate 15,144 watt-hours in 6 hours of daylight, you would need an array of solar panels rated at AT LEAST 2,524 watts. And a large bank of batteries to store up enough charge to last through the night, until the sun shines again. You would need to produce 2524 watts for 6 hours, to provide for your average use of 631 watts for 24 hours.

    Oh, what's that you say? The sun doesn't shine every day where you live? Well then you would need to double or triple that battery bank to tide you over until the next sunny day, or run a generator for a few hours to charge up your battery bank.

    First thing to do would be to shut off the air conditioner and open the windows. Park under trees for the shade. A figure I seem to recall from the website at www.homepower.com is that for every $1 you spend on buying more energy-effecient items, you can save $4 on an alternative energy system. Put another way, you will need to make some serious changes to your energy usage to make solar worthwhile.

    What appliances do you have on this RV? A/C? Fridge? Water heater (gas or electric?) Microwave? Laundry?


    I think Rambler's '3 things' hit it on the head for most of us. His math is right too :)

    John
     
  8. WisJim

    WisJim Well-Known Member Supporter

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    Like John says, check out Home Power magazine. Their current issure is a free download at www.homepower.com. Buy back issues, either on CD or paper, and go to an energy fair, such as the one in central Wisconsin in June http://www.the-mrea.org People from all over the world attend, and if you are serious about learning about solar or wind power, it would be worth a week of your time. Or this one in North Carolina (no personal knowledge about this one, but I have attended the one in Wis every year except the first) www.seeexpo.com, or one in Kentucky (likewise, I haven't been there) www.bluegrassenergyexpo.org

    The more you know, the bettere decisions you can make.

    Jim, using wind and PVs in Wisconsin since 1977.