New Member: Harald

System
System Posts: 2,511 admin
Thanks for making this forum available.
I will be new to off grid as Pacific Power company wants quite a bit of money to hook me up at my new location. I am in eastern Washington State and the power would have to come in about 600 foot.
So first thing I am in process of converting a few things to propane; tankless flash water heat, range, and perhaps refrigerator. I have a small refrigerator, 3.6 cubic foot, that I was surprised to learn uses about .6 kwh in 24 hours at this time of year. So I might go with that solar powered instead of propane refrigerator.
Perhaps I only need solar to run my submersible pump, few lights, and my computer. The well is about 150 feet deep and I will likely draw water from about 100 feet. The computer and Lenova LCD together only take about 50 watts when idling.
I live alone and do without things like microwave, tv, and I heat with my own wood.
It is a little scary to leave the power company behind, but at the same time it will be very satisfying. I will be reading everything here to learn. But, I don't have much time so I will likely just have to jump in and get a panel, controller, inverter and battery.
Again thanks for making all of this free expertise available.
Harald

Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: New Member: Harald

    Whoa there Hoss,,, hold on a minute!

    Seriously,, Welcome to the forum.

    My first and perhaps best suggestion is before you succumb to the "ready, fire, aim syndrome" I suggest that you spend 12 hours and read EVERY thread on the solar beginners and off grid pages in this forum. This will give you a broad base of information to get started. There are some very smart folks who have spend decades in some cases "being there doing that" so that we don't have to reinvent the wheel at every installation.

    My next suggestion is avoid the trap of overestimating Pv system input,, and coincident underestimating loads. Most newbies do both. The very first thing you need to do is do some serious calculations on your loading side,, erring always on the assumption that you will use more, not less energy. Add in a fairly large fudge factor for growth over time. After you have a pretty good handle on the loads you then can begin to look at the PV side.

    As for the PV side,, go to : http://www.nrel.gov/rredc/pvwatts/version1.html or some similar solar calculator to get a sense of what you will be able to generate on a daily/monthly basis through out the year.

    Then knowing how much you are likely to use, and how much you can generate with given system,,, you can start designing your own system. Being off grid you will have to calculate in a number of system efficiencies that you wouldn't have to with a grid tie system. For example, panel ef, wire loses, charge controller ef, battery charging ef, inverter ef etc. I use a simple back of the envelope calc that says: take the name plate rating of the PV, divide this number in 1/2 to account for total system loses, multiply this number by the number of hours of GOOD sun you can expect on average,,,rarely more than 4 hours, and that number gives you a pretty close idea of how much energy you will be able to harvest on a daily average basis.

    Now you will have to figure in a reserve for days without sun,, most people like 3 days minimum, and you will have to size the Pv array and battery bank for this reserve. Most people suggest never discharging a battery bank more than 50%,, personally I don't like to discharge more than 20% routinely.

    Finally you will have to figure out a generator aux charge system for either peak loads, or days without sun. This can reduce the reserve size of the battery system if you are prepared to run a genny more.

    After you do all of this you can begin to get an idea of how much this is all going to cost. The reality,, if you are going to live there full time,, you may very well find that grid power,, even at a high install cost is a bargain compared to Pv. In general off grid Pv cost about twice what grid tie Pv does for similar wattage.

    Your best Pv $$ is conservation. Every dollar spent on conservation will save ~10 in Pv cost. I agree with you about LP vs good energy star fridges,,, as I have said often, if I were to do it again I would have up sized the Pv and bought a energy star fridge.

    One finally suggestion,, you might consider pumping your water with the generator. Pump into a large (or series of large ) storage tanks once every day or few days while the generator runs. Then you can make you Pv size much smaller since you don't have that big load. You can also pump water that way while you are using a genny for other things like shop tools. The trick to gennies is running them at ~75% load to keep them efficient.

    Good luck, read all you can,,, and ask what ever questions you need to,

    Tony
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: New Member: Harald

    Welcome Harald you should find plenty of advice and help here. You will have to crunch some numbers on you power consumption to size your system but here is a few tips from me.

    1. Go for a high base voltage for your battery bank. 48v if possible as this will save you on wiring costs allow a larger single string battery bank (less strings less complications) and allows more PV solar capacity on a single Charge controller. Like for like there are no cost hits for 48v over 24v or 12 volt

    2. Factor in at the very beginning the purchase of a battery monitor for your system.Then read up everything you can on battery care and maintainance.

    3. Take time and attention to designing and fitting a good well grounded earth system. Which will then allow you to provide Lightning protection to your Inverter and Charge Controllers

    4. Design your systems to allow for upgrades ie more solar panels is easy, but adding extra batteries later on is a no no and upgrading your inverters and charge controllers are costly.

    5. Use correct DC rated switches and fusing were required

    6. Avoid the ready steady fire aim system of planning


    HTH Nigel
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: New Member: Harald

    Opps

    Your best Pv $$ is conservation. Every dollar spent on conservation will save ~10 in Pv cost. I agree with you about LP vs good energy star fridges,,, as I have said often, if I were to do it again I would have up sized the Pv and bought a energy star fridge.

    This should have been at the Top of My Tips list also:blush:

    Plus every thing Tony said:p
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: New Member: Harald

    I did a cost comparision in Spain over a LPG Fridge Freezer versus a New A+ FF and more PVs to run the A+ FF. Taking initial purchase price + cost of fuel + extra solar panels as the only factors, it takes less that 3 years for the PV and energy efficient fridge freezer to becoming the winner. After that the gas bills outstrip the original cost purchases of each system .
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: New Member: Harald

    To talk out of both sides of my mouth,,

    If a place is only used part time,,, seasonally, or weekends, or the occasional holiday week or two LP fridges usually win. Their initial purchase price is higher, (although you can get some bargains from the used/RV wreckers,,, there is one in my local paper for $100) but amortized over they number of hours or days used, compared to the added solar cost,,, Lp probably is cheaper.

    As I have suggested elsewhere here,, there are a number of things that can be done to LP (and conventional fridges for that matter) fridges to increase efficiency. The first is ensure good venting,, using a t-stat controlled muffin fan to draw heat off the condenser. , with a fresh air vent low, behind the fridge to give it a natural draft. The second is to add additional insulation to the fridge cabinet. You can add 2" of stryofoam or thermax,, and increase the net r-value of the cabinet by a factor of 2 or so. Finally adding a tiny interior fan to circulate air inside the cabinet serves to shorten run times. I figure that my run time is ~40% of the time when the temp is ~28c (~85f)

    Tony
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: New Member: Harald

    My maths was based on buying new ff and operating 24/7 365 days a year.:cool:
  • System2
    System2 Posts: 6,290 admin
    Re: New Member: Harald

    Thank you all, many good points. I did read quite a few posts prior to my initial post. That is why I came to conclusion to move what I can to propane. I do see that a novice can easily overstate what can be accomplished with solar. And I am strongly considering the suggestion to pump the water with a generator's power. In fact my plans now include doing that very thing. It really only leaves the computer and lights.
    yes, I would very much like to have grid power, but US$15,000 is a substantial amount for me right now. I visit every day and read the posts. And I guess I need to brush up on my math. It seems so complicated.
    Maybe I should spend half the year in the south.
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: New Member: Harald

    Good luck and come here and ask as much as you want BB/niel AND OTHERS s will crunch figures 4 u and others will always give u help,,,, but help your self by searching and visiting NAWS for great FAQ pages,

    Then look after the sponsor and buy from him,,, without NAWS this forum wouldnt exist and he allows more artisic licence than I would if i ran this site . I live in another continent and it doesnt apply to me but include in your pricing the added value of NAWS
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: New Member: Harald

    One way to come into it slowly is to design your battery bank around your known loads. Use your generator (properly sized/designed) to pump water, run appliances AND do much of your bulk charging,, using solar to top off the batteries. ( The bulk is the hardest to get in) Then you can add panels as a budget would allow.

    If you go this route make sure that you understand the nature of your batteries,, what they can and cannot due,, and size your components to "grow into". Too many people start too cheap/too small, particularly with charge controllers and battery chargers.

    Finally,, $15 k might seem cheap by the time you get done. A full blown off grid system might run better than $10/watt AND you have to replace $1000's of batteries every 5-10 years.

    As has been suggested before,, read all you can, ask questions as you need to. This will all make sense as you begin to figure it your. There is a very similar thread going about a Maine Island off grid project. His needs may be a bit more,, but if you read that thread from the beginning, you can see how he has worked his way through the mine fields. As I have so often suggested, there are plenty of very smart folks here, who have spent decades inventing the wheel,,, so that we don't have to.

    Good luck,

    Tony