Off Grid in Oregon

Options
gomango
gomango Registered Users Posts: 24 ✭
in Solar Beginners Corner #1
I an not new to off grid. I grew up in a small cabin that started with propane lights and a car battery for a couple lights and a small 12" TV. (not the best, but its all that was needed)

Now that I have moved back to the homestead, I find that my big city ways are hard to kick, and my wife has an even harder time with it. I have a 16 year old son that has no concept of shutting things off to conserve, and loves to jam on an electric guitar. All was well until he dragged home a 200 watt amp to jam with. We have restricted him by purchasing a small 3 watt amp.

Here is the current situation.

House is being completed and is almost livable. I have wired it for minimal 110 and have installed CFL lighting throughout. Water is gravity feed, and the hot water is solar in the summer and wood stove in the winter. In the in-between times we run from a propane instant hot water heater that throttles back when the stored hot water from the tank hits it. The refrigerator is a Dometic propane unit and the cooking stove has not been located yet. I am watching the locals here for a good propane version as well. The power is provided with a triplite 1800 watt inverter and is actually on a different house and temporarily jumpered to my house until I get my system online. The current system that powers me and the other house is two L16's and a couple 80 watt panels. I am thinking I will need a bit more to keep my family's power habits up and running.

Last year I took the time and installed a micro hydro on the creek, and we are currently drawing about 7 amps at 12 volts from a creek that runs about 4 months out of the year. This actually supplies us with enough power in the winter where we don't need to run the Honda generator at all.

Here are the power habits my family has, and once the house is done I fear for the worse. Probably about a 50% increase or better. Im just being realistic. If I build it they will use it when I'm not looking.

3 persons
15 watt CFL lights for an estimated 3 hours per person per day. (double in winter)
32" LED flatscreen and DTV receiver about 2 hours per person per day.
Satellite internet, router and laptop about 5 hours total per day.
An electric guitar about 3 hours per day. (3-5 watts)
An electric dog fence 24 hours per day. 2-3 watts


I picked up a steal on a three year old inverter a few weeks ago, and am dieing to build a system to feed it. Its an outback 2024. I just need some help sizing the system to keep it all going. The 1800 watt inverter has kept up pretty well up to this point, but I really need to get off the neighbors system and start living off of mine. We have just about worn out this little honda generator trying to keep both houses going.

The system will need to be 24V, solar with flooded led acid batteries. I am looking at industrial forklift batteries simply because of the cost. They are rated for higher DOD than the standard L16 batteries that have recently hit $350 each. The forklift battery will be about $2000 and will have over 1000 ah/20.

This is where I am at at the moment. I have been watching the solar prices and looking for deals, but none have caught my eye as of yet. I have found one option, but need to research it a bit before I blab it here and get my foot stuck in my mouth.

More later. Please jump in and give me some ideas. I am doing this all payday to payday, so funds are saved then splurged.

Thanks
Dave
· Share on Twitter

Comments

  • gomango
    gomango Registered Users Posts: 24 ✭
    #2
    Options
    Re: Off Grid in Oregon
    gomango wrote: »
    I picked up a steal on a three year old inverter a few weeks ago, and am dieing to build a system to feed it. Its an outback 2024.

    Allow me to clarify... This inverter is 6 years old. It was taken out of service after three years of use for an upgrade.
    · Share on Twitter
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #3
    Options
    Re: Off Grid in Oregon

    Fyi,, and I only have a minute,

    We live off grid with propane fridge. We use ~600 wh/day, from ~400 watts of PV charging 450 ah of batteries.

    Before you build a system around any inverter (or any other hardware for that matter!) do an accurate calculation of you loads. Remember the basic rules,, loads will always grow with time, people almost always over estimate their PV input, and under estimate their loads.

    Systems have limitations as to what can or cannot grow as demand grows. Pv can be added assuming the charge controller has "head room", batteries don't like to grow. Inverters that are too big tend to be quite inefficient.

    The other quick rule of thumb is, take the name plate rating of your (expected) PV, divide that number by 2 to account for total cumulative loses, then multiply that number by 4, with represents the average number of hours you can reasonably expect on any kind of average basis. (Folks often think they have more, but in reality they don't,, usually).

    So a 1000 watt PV might look like this net/net: 1000/2=500*4=2000 wh/day.

    Do you load calcs and see where you end up,

    Welcome to the forum, keep in touch and good luch,

    Tony
    · Share on Twitter
  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    #4
    Options
    Re: Off Grid in Oregon
    gomango wrote: »
    Im just being realistic. If I build it they will use it when I'm not looking.

    Dave, you got me laughing with that!!

    I would just add that, since it sounds like this is a normally-occupied home (vs. weekends and/or vacation), you work your system toward an electric refrigerator. I lived on two propane Dometics for years (after years with a luke-cold Sibir) and propane costs got to where it was almost $40/month to power each one.

    I run our house on three inverters: one for fridge, micro, washer, dryer and a few lights; the second for TV, sat, stereo, the rest of the lights (and a guitar amp if we still had a teenager) and the third to supply water pressure (which your gravity-fed system eliminates).

    Since it sounds like it is still a possibility I'd recommend you wire your home with TWO 120V circuits. They can be tied together at first, but having tried it both ways, using two inverters prevents "brownouts" on your TV when the wife starts the washer, for example. It's also a ready backup should an inverter fail.

    Phil
    · Share on Twitter
  • gomango
    gomango Registered Users Posts: 24 ✭
    #5
    Options
    Re: Off Grid in Oregon

    Phil,

    It had never occurred to me to split the load across multiple inverters. I could run the smaller 800 watt xantrex inverter I purchased for a backup to operate the household lights and other annoying small power sucking devices and use the larger inverter to power the household power hogs.

    The only problem I see is that the xantrex is 12v and the outback is 24v. This would require an additional small 12 volt system to power the xantrex. I guess I could sell the xantrex, and upgrade to a smaller 24V inverter as the second source. The electrical panel is indeed easily modified without changing the wiring scheme. All I need to do is remove the jumper between the two breaker buses and viola... two branches already set up. I would just need to move circuit breakers to the appropriate branch depending on where I want the load running from. Kudos on that idea Phil.
    · Share on Twitter
  • gomango
    gomango Registered Users Posts: 24 ✭
    #6
    Options
    Re: Off Grid in Oregon
    icarus wrote: »
    So a 1000 watt PV might look like this net/net: 1000/2=500*4=2000 wh/day.

    Do you load calcs and see where you end up,

    Tony,

    Thanks for the solid advice. I am still in the process of gather future planned appliances and lighting in order to design the system. I joined up here to pick all your brains about this process, so your input and experience is most welcome.

    Dave
    · Share on Twitter
  • russ
    russ Solar Expert Posts: 593 ✭✭
    #7
    Options
    Re: Off Grid in Oregon

    What part of Oregon are you in? İ grew up in Madras - central part of the state.
    · Share on Twitter
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #8
    Options
    Re: Off Grid in Oregon

    Just as an FYI,

    I wouldn't mix battery voltages on the same system. To build a 12/24 vdc system has a number of problems written all over it, IMHO,

    Tony

    PS Phil's point on the fridge is good one, one has been repeated over and over here. The more full time you are, the faster the balance tips in favour of a conventional energy star fridge. (If I had one thing to do over again, it would have been to go with a conventional, but we were already invested in the propane,, perhaps when it dies.)

    That said, you can make a good Dometic a bit more fuel efficient by adding foam board to the cabinet, installing a t-stat controlled fan on the condenser coils, and making sure the fridge is well vented.

    I figure that mine runs ~ 25% time, at 1500 BTU/hour, ~1/10 of a gallon per day.

    T
    · Share on Twitter
  • gomango
    gomango Registered Users Posts: 24 ✭
    #9
    Options
    Re: Off Grid in Oregon

    Im in the mountains above Medford.


    The fridge was free. It released all its goodies in the previous owners house and I ordered a new cooler for $400 so the total investment for the fridge was about $500.

    I was thinking about the duel voltage issue the other night. I feel your correct by saying there are many issues. I think I am going to take a step back and watch for a smaller 24v inverter to power the smaller loads.
    · Share on Twitter
  • AntronX
    AntronX Solar Expert Posts: 462 ✭✭
    #10
    Options
    Re: Off Grid in Oregon

    Here is one good 24V inverter: http://store.solar-electric.com/xp-600-24.html Its runs efficiently at low power loads. Peak efficiency is 89% at 300W. At 75W load eff. is about 85 - 87%. But it does not like too many CFL bulbs. It makes audible buzzing noise with 6 or more lights powered from it. But power factor corrected ballasts for T8 lights makes it happy. You should run sepatate wiring circuit for all of the lights in your house. Then you can try to power all your regular 120V AC compact fluorescent bulbs with 60 - 74V DC using boost dc-dc converter. Or if one day 12 - 24 - 48 V screw in CFLs become cheap and available, you can easily switch to them. Running your lighting directly from battery bank has many advantages.
    · Share on Twitter

Categories