Help with materials needed for generator/solor combo

Discussion in 'Off Grid Living' started by Shannon Wyatt, Jun 17, 2015.

  1. Shannon Wyatt

    Shannon Wyatt Monkey

    I am building an off grid cabin (16x20) and need some help on a material list and what size things I need. I can give someone all the details on what I will be running but just need some advice on what I should buy. Cabin is already wired and I have a generator. Need help on battery bank, solar panels, charge controller, inverter, etc.... Thanks for the help in advance
  2. ghrit

    ghrit Bad company Administrator Founding Member

    Shan, there's a lot of help on the Monkey for you. But first, other than a long winded discussion of brand name suppliers, there's a lot of info needed to tie things up in a bow for you. Loads you intend is but one thing of many. Like, for examples, where is the cabin? Do you need to have heat in the battery bank enclosure? Will your solar panels be in the sun from dawn to dusk, or partially shaded?

    There are several threads on powering off grid cabins, well worth your time to poke thru them for more info and hints.
  3. Shannon Wyatt

    Shannon Wyatt Monkey

    ghrit, thanks for responding. Well if its ok with you I can post the details here or email them to someone. I can be specific and can give details on what I want to run with it. Just need a list of items/brand that I need.

    Just let me know what I need to do
    Last edited by a moderator: Jun 17, 2015
  4. Dunerunner

    Dunerunner Brewery Monkey Moderator

    Welcome to the monkey, Shannon.

    Just give us the list... We'll work it out...
  5. ghrit

    ghrit Bad company Administrator Founding Member

    Gotta say, your initial question is way too broad and lacking enough details to do any real designing. Methinks, and others might disagree, that you would be better served at this point by reading some of the other posts on the subject. That should focus your design details and allow for more specific questions. Then again, I'm not off grid. But if I were planning to go off, that's how I would start.
  6. Shannon Wyatt

    Shannon Wyatt Monkey

    Thanks guys.... ok details on the cabin. 16x20 off grid cabin located about 15 minutes north of Birmingham. It will just be a weekend getaway for me.... We be used sporadically. Will probably use it one day a week. Here is what I plan to have it in.

    - Will have 6-8 lights all using LED bulbs and using less than 10 watts each. Lets say 100 total if they are all on at once
    - Flat screen TV for a few hours at a time. Probably 300 watts
    -DVD player- 50 watts
    -Satellite receiver- maybe 50 watts?
    -small deliver pump for pressure when using water. Very little usage- 100 watts Will have 250 gallon tank for water supply
    -small fridge that I will only keep on when I am there on a weekend night. 300-400 watts?
    -small 10,000 btu a/c unit 1200 watts Will just run it when needed.
    -Maybe microwave very little 1000 watts

    Here is my plan...... Use solar panels/battery pack to power everything but fridge and a/c. I would like to have a generator wired in so when I want to use a/c, microwave and run fridge the generator can be used. Would also like generator to charge battery bank when running. If you take out the pot and a/c my wattage requirements are very low. And I will only be using the cabin probably one day a week. If I didn't have the a/c, I think I could probably just get by with solar and batteries. But I need a/c sometimes.

    I stress the cabin will be used very little so as far as equipment I would like to go as economical as possible. I already have the generator so I am ok there.
    Last edited by a moderator: Jun 17, 2015
  7. BTPost

    BTPost Stumpy Old Fart Snow Monkey Moderator

    Ok, from a practical point of view, of one who lives with a very similar, but a bit more Energy Usage....

    I would bring the Generator into small Breaker Panel. Maybe a 6 Hole Panel with a main Breaker. (I like SquareD stuff) and the AC, Inverter/Charger Input, and a few Outlets, as Loads. The Inverter/Charger Output is wired to a second, small, Breaker Panel for the Inverted Loads, Lights, Refer, Electronics Etc, and the rest of the outlets. Plugin Kitchen items (Microwave Etc) can be plugged into outlets, powered from either Panel, depending on if the Genset is running, or not, and the Charge State of the Battery Bank. Whenever the Genset runs, the Inverter/charger switches to Charging Mode, which recharges the Battery Bank, as well as can supply any major Loads, that are connected to the Generated Plugins. That solves you Heavy Load issues. Then for the Solar Portion, buy a GOOD MPPT Charge Controller, and program it to do the conversion from Panel Voltage to Battery Bank Voltage. For the Inverter/Charger, and Battery Bank, you will need figure out just how much Power, (WattHours) you plan to use from your system, on each visit.
    Rule of Thumb for Inverter/Chargers & Battery Bank, is by expected Loads.
    1000-2000 Watts Minimum 12Vdc Inverter/Charger DC Input and Battery Bank Voltage.
    2000-4000 Watts Minimum 24Vdc Inverter/Charger DC Input and Battery Bank Voltage.
    4000- and Up Watts Minimum 24Vdc Inverter/Charger DC Input and Battery Bank Voltage.

    Battery Bank Size will depend on Expected Loads and ReCharge Time while you not there.
    More AmpHours means you can run the whole weekend without Running the Genset if AC isn't needed
    and with a proper sized Solar, it will reCharge the Battery Bank while your not there, during the week, just
    waiting for your next visit. You also have to ALLOW for Bad Weather, (lack of Sun) during the week, but that
    is NOT as critical, as you already have a Backup Genset, should you arrive and find the Battery Bank, not at
    Float State.
    The Water Pump is most likely 12Vdc already so it can be just tied directly to the Battery Bank if you are running
    a 12Vdc System. If you need a 24Vdc or 48 Vdc System (Not likely in your Senerio) then there are DC/DC Converters,
    that can do the Voltage conversion for you. Do NOT put a 12Vdc Load, across half of a 24Vdc Battery Bank, for
    ANY Reason... It messes up the Battery Bank Stability, in Charging and Discharging, and shortens the Battery Life,
  8. Shannon Wyatt

    Shannon Wyatt Monkey

    BTpost, do you have a phone number I can reach you at. Thanks for the help
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