Wednesday, October 14, 2009

Hey Off Grid ! Your Anwser.


The system design is just an example of a "backup" system the typical D.I.Y. could build himself with not much cost involved .
The components selected are matched to the system capacity ,

The larger inverter would require a much larger solar array to charge a much larger battery bank and much more dollars later ya got a Big System !

Look at the backup system and what it would be used for. Temporary grid outage , these generally last a few hours no longer than a day in most cases ,You would have 5 amps @ 120volts that has the ability to recharge each day to full battery capacity with each days sun , giving you CFL lites , computer , modem and small lcd tv , and no more just the minimal to get bye on.
you got only 2 125 watt panels to charge 4 battery's running a 600 watt inverter(5 amps) with built in receptacles ,simple and for the cost its a real deal.You could also use this every day to trim a little off you electric bill each month

What you need to understand is the ability to recharge what you have is what makes it renewable .
also for this example cost out lay up($3200.00 ) front to go from a backup system to a good reliable 1500 watt system (12 amps 120volts)would double or more ,inverter $850.00 to $1200.00 ,battery's upgrades to meet expected demand from larger inverter would double again to 1200.00 or more, because this is where you decide to up grade the battery system to better battery's so instead of $600.00 you jump to $1800.00 to 2000.00.
To charge to larger bank would require triple the solar watts to 750 watts or more 6 125 watt panels , again triple the cost $3500.00.

Now ya got some money here and would need a qualified installer to put it together 1200.00 inverter , Battery's 2000.00 ,P.V.panels X 6 = 3600.00 plus charge controller and additional cabling necessary the system cost have gone to 7200.00 plus installation add 1500.00 .Now your reaching 8500.00 plus.

just increasing the inverter wattage output dose not upgrade the system.

hope this helps



  1. Cool, a post just for me .. it must be my birthday. hey it was on the 7th. thanks and I think that is a great intermitant system.

    I for one would use a small generator and battery bank of 6 trojans with a cheep 1500 watt invertor ( buy 2 of them for $300) for stricktly only when power goes out system. and I wouldnt expect it to last at all for anykind of long term use. but I would only have $1200 into the system and I could afford to replace it every 5 years. BUT that is not at all what I'm going for and must gear up of quality and the expense of a decent long term system like you know how to do. I'll be in touch.

  2. Ok' OffGrid,
    I don't know how to answer this one, Buy I'll try!

    First using the generator to charge full time?
    The cost and hassle of fuel + cost and wear and tear on mechanical equipment.

    The backup system would be enough power for an ultra conservative person to become completely offgrid sustainable with only 5 amps of power to start off with.

    The equipment I design into my systems are industrial quality,heavy duty,long life,low maintenance, field tested products !

    The idea of a generator running instead of harvesting the wind and sun to recharge the battery's dose not make sense to a guy like myself.

    You might as well run the gen set full time and put a 5000 gallon fuel storage tank on your property.

    My thoughts of trying to do this for a dime on a dollar doesn't add up ,especially the part about replacing every 5 years ???

    This style of living can be done on the fly for cheap,and remember you "Get What You Pay For " or done right the first time around with some cost out front and expectations being met.

    Instead of disappointments because there was no engineering or product knowledge presented before the money was spent!

    You have to change your idea's of using lesser quality products to save money ,You must come up with a plan for the complete system design first!Build a basic power center to get up and going using quality components from the start!

    Then add to it over the next 5 years ,instant gratification dose not apply here if your doing this on a budget by yourself.

    So back to the drawing board !

    Beginning with your total wattage usage per day and your DC system voltage 12 , 24 , 48. before you even spend a penny.
    As it's difficult to change this very important decision after you have started or have invested money.

    I told ya I would lend a hand on design.

    I do this as a favor for a friend ,

    Most folks who started a solar system by them selfs experenced thoughts after they started the build out,that they were over there head before they even got the battery's charged the first time.

    get back to me.



  3. Your right, but listen. we are both saying the same thing. I would only use what I comment on if I was connected to the grid and power went out only 2-4 times a year.

    That is totally differnt to what my system would be.

    I lived like the amish in Alaska for quite a while. I will only be modifying that kind of lifestyle a little to live in the desert. I have some modifications to Karkool evaps, Trucker refrigerators, solar heated water , and Solar lights, that will allow me to live a little bit more modern than I did in Alaska. Along with 12 volt rv pump to a 10-20 gallon pressure tank, which wont cycle but once a day.

    unless I go out to eat I dont eat cooked food. I will try to use solar cooker. eventually I will be using solar cooker for meats but Im not gonna fridgerate much at home. I do jerky alot.

    See my usage is much lower than that of most people. kinda like camping on a regular basis. I found I can do that as long as my house is comfortable, and as long as I have time to do chores the old way. whats important to me is to keep usage way down and consume little.

    I hope there will be a regular local supply of goat milk, chicken eggs,wild rabbit/bird, And a swimming hole or river within a short drive. I might have to pay someone 150 bucks a year to deliver extra water until I get my rain catch system up to par, but that is a figured cost.

    my lifestyle is unfathomable to those with families Women and kids. but I dont have that problem. My daughters system might be a different story.

    I know I need to explain this to you because U were visioning a differnt life style for me i think.

    This is ust talking out loud and Im a student.