to begin think ''off-grid''

hello there! would very much appreciate advise on how to start assembling an off-grid electric power system w/gas tsw generator (1.6-2,8kVa) & ups for 300-800w/hr load w/later adding pv panels &, possibly, wind generator.
should power 2 dc circulating pumps-radiant heating & solar water heater, 7-10 lLED lamps 5hrs/day, laptop (TV) 2-3hrs/day,basic fridgefull time, well-pump .8kW 15min/day.

Comments

  • icarusicarus Posts: 5,108Solar Expert ✭✭✭✭
    Re: to begin think ''off-grid''

    Before you do anything else,, read all you can, here and other places. The absolute first thing to do then is to do a serious load calculation. If you don't realistically know how much load you are going to have it is sort of crazy to try to design a system.

    Figure out the loads that you wish to power by the PV and which you might use the generator for. Are you going to be full time, or part time? This may make a difference in terms of fridge selection. Full time might warrant a 120vac fridge and a bigger system, part time perhaps a propane fridge.

    Remember when sizing components that loads WILL grow with time. Battery banks SHOULD not be added to later, but PV can be . Try to size component with room to grow into, especially charge controller and inverters.

    For example, as you have begun to think, your numbers belie the difficulty in figuring loads. (Use a kill-a-watt meter to gauge your current consumption) You state "TV" How big, how much,, satellite receiver? Surround sound? Fridge? What size,, how long, how many Kwh/day? Lap top? How much, how long,, modem, satellite modem, router, printer?

    Try to think of all the things that use electricity and you will be surprised at how it adds up.

    Just for the record, we live off grid, and use ~4-600 watt/hours/day for everything. No TV, no solar pumps etc.

    Tony
  • BB.BB. Posts: 27,681Super Moderators admin
    Re: to begin think ''off-grid''

    Besides measuring your loads with a Watt*Hour meter (or, you might want to wire up an old utility meter to measure your typical/average daily loads).

    I assume you are around Moldova, so unless you have 120 VAC @ 60Hz, the Kill-A-Watt will not help you.

    Use this website and pick a location near you (I used Odessa, Ukraine). For a general idea of how much power you can generate per month, use 1 (1 kW=1,000 watts) for solar panels (smallest program will accept). Use 0.52 for derating (battery + inverter) and accept the rest for defaults.

    It appears that you may have a pretty harsh winter there (lots of cloud cover), so you cannot collect sun for almost 1/2 of the year.

    This serves to make solar power even more expensive for you...

    In the US, this would make your solar power cost something like $1-$2 per kWhr (over 20+ year life of system, plus battery replacement every 5-10 years). That is about 10x the cost of utility power (in the US), and it might cost you more than an efficient generator and fuel (at least in your area--given the cost to purchase solar equipment).

    I have to go right now--but let us know more about your needs and expectations. And if I have your location correct or not?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Posts: 27,681Super Moderators admin
    Re: to begin think ''off-grid''

    One other place you might want to look at is the Outback Website... They have a whole section of drawings for various sizes and types of Off-Grid configurations.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: to begin think ''off-grid''
    BB. wrote: »
    One other place you might want to look at is the Outback Website... They have a whole section of drawings for various sizes and types of Off-Grid configurations.

    -Bill
    thank you bill.certainly will have more appropriate questions in aweek or so. this site has been helpfull in getting faintest clues on how those things are approached. good pun about moldova!;)
  • BB.BB. Posts: 27,681Super Moderators admin
    Re: to begin think ''off-grid''

    Greg,

    Pun? (MOLDova and "harsh winter"?). Everyone's IP Address is attached to their posts, and we try using the Internet (such as this site) to estimate where somebody is located when we are asked about solar power. These programs are pretty close about 90% of the time--and sometimes they are way off.

    I am sorry, but no pun was intended. I hope I did not offend you somehow.

    Since solar power, needs the sun to work--knowing roughly where somebody is helps in planning on how large a system and how many panels it will need (as well as having a good estimate of power requirements).

    Solar power is very expensive, and we try to help size a system that will support the loads needed, and encourage conservation, to keep the costs as low as practical.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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