total new, need tips and input

Teapopper
Teapopper Registered Users Posts: 13
Hello All

I am a total beginner and need some guidance.

First thing i did was to buy a kill a watt tool and have checked the appartment on what i use power on.

Im thinking of buying 15 pieces of these Truck batteries and chain em.
http://www.tradekey.com/product_view/id/81521.htm
I can get in a local store for 76 Euro per piece.

Then i need solar panel, how many ?l, inverter ++ ? to meet my needs , need some imput here.
Will this help me get off the grid ?




I live in Norway.

So far me and my gf have the following,
1 PC stationary, 120w, runs 8 daily
1 monitor, 70w 8 hours daily
1 laptop, 70w, runs 8 hours daily
Lights, 300w, runs from 10-12 hours, all is gonna be changed to LED asap !
Ventilation 37w runs nonstop
Electrical heater, 1700w when used so about 1 hour, winter coming so prob more
Refrigerator, 80w
now.
Aquarium 40Watt, runs nonstop.
Water tank, ?


And we have other stuff like vacuum cleaner, stove and washing machine.

Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: total new, need tips and input

    You did the right thing by buying the Killawatt! Other than that, I would suggest that you spend a lot of time reading everything you can, here and elsewhere about Pv before you buy ANYTHING! IMHO the most common newbie mistake is "ready, fire, aim!" That is buying stuff because it seems like a deal, only to find that it won't work very well with the system you finally end up with. Then you are left with some bad taste in your mouth, and you may well have wasted scarce money.

    Welcome to the site. There are some very smart folks here, many who have forgotten more about RE/PV etc than most of us will know. Use their experience so that you don't have to reinvent the wheel at every turn.

    Good luck,

    Tony
  • Teapopper
    Teapopper Registered Users Posts: 13
    Re: total new, need tips and input

    Thnx for reply Icarus !

    Yep, so mutch to read, great forum !.
    First thing i will do is to change the lights to LED.

    Thinking of just buying one cheap battery and a cheap solar panel just to get the feeling and do some experimenting.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: total new, need tips and input

    The reality is you first must define your loads, then you can work backward to see how much Pv you might need. Remember that conservation is your best RE dollar. In rough numbers every dollar spent on conservation will save ~$10 in Pv costs.

    Grid tie PV will run $5-10 per watt before any rebates/tax credits etc. Battery based off grid will roughly double that. Battery based systems only run at efficiencies in the 50-60% range net/net, while grid tie based systems can be in the 90%+ range. So in addition to costing more up front, you get way less bang for your buck with a battery system. If you have grid power available consider using grid tie. Except for hobbyists, off grid battery systems when the grid is available are pretty expensive relative to their utility.

    Good luck,

    Tony
  • RandomJoe
    RandomJoe Solar Expert Posts: 472 ✭✭✭
    Re: total new, need tips and input

    Be careful with your expectations! I'm not much beyond "newbie" myself - only got into all this a bit over a year ago and really serious at the first of the year. It is a bit disappointing to find out just how hard (and expensive) it actually is to power a modern home yourself - and a real eye opener just how cheap grid power is in comparison, when it is available.

    You mention an apartment, what kind of exterior space do you have available for solar panels? And does it face south? What you describe for loads is a substantial system, and you are going to need a fairly large chunk of space to power all the things you list.

    Adding up your total loads:

    PC: 120W x 8hr = 960Wh
    Monitor: 70W x 8hr = 560Wh
    Laptop: 7W x 8hr = 560Wh
    Lights: 300W x 10hr = 3,000Wh (Ouch!)
    Vent: 37W x 24hr = 888Wh (Good example of the problem with continuous loads - they add up!)
    Heater: 1700W x 1hr = 1700Wh
    Fridge: 70W x ??? = (Mine is close to that wattage, averages out to 1,600Wh per day.)
    Aquarium: 40W x 24h = 960Wh

    Or, rearranging a bit:
    Computers: 2,080 Wh/day
    Household: 6,300 Wh/day
    24 hr loads: 1,848 Wh/day

    Total: 10,228 Wh/day (or 10kWh per day)

    The general rule of thumb for batteries is three days reserve, and with lead-acid you don't want to go below 50% DOD too often or their lifespan is greatly reduced. At the wattages you are looking at, I'd go with a 48V system so to find how many amp-hour of batteries is needed:
    10,220 Wh / 48V = 213Ah used per day x 3 days = 640Ah x 2 (to stay above 50% DOD) = 1280 Ah.

    With the batteries you listed (12V 155Ah) you need four in series to get 48V, and eight of those strings in parallel to get to 1240Ah. Or a total of 32 batteries! That's a LOT of space! And with flooded cells you don't want them inside your home, they need lots of ventilation.

    The solar panels are similar - and you need another piece of information here, your solar insolation. There are maps available online that show this but for some reason I have a hard time finding them! ;p I did find that Norway's average is quite low, which compounds the problem. I'm in a pretty decent area, my low insolation in winter is 4.9, and even here I'd have to have quite a few panels to generate 10kWh/day:

    10kWh / 4.9 = 2,040 W input from the solar panels (and unless you are in *ideal* conditions - which don't exist! - you won't get manufacturer's ratings). Forgetting inefficiencies, panels not providing nameplate ratings, all that, I would need four times the array I have now (540W) - being generous, that's an area about 20 feet by 10 feet (or some combination thereof - my panels are roughly 5 feet by 2.5 feet, would need 16 of them).

    Of course, we can't get away with forgetting the inefficiencies - charging and discharging batteries is not perfect, inverters and charge controllers have losses, panels not perfectly aligned with the sun don't quite perform as well as they could. So you may well need more than that to do the job. (And if your insolation is substantially lower than mine, you could need a LOT more!)

    If I haven't scared you off already... Conservation is definitely easier/cheaper than solar power, and will give you far more bang for the buck. You mention changing to LED lights, that's the kind of thing that's needed, to reduce your total power requirements. Your computer monitor is stout! Newer LCDs (especially with LED backlight) are significantly lower. Laptops draw less than desktops. You can also start smaller, the way many of us did, and just pick some "critical" loads (or whatever criteria you want) and take just a few smaller things off-grid. In my case, I picked the things I wanted to keep going in a power outage. (Lights, ham rigs, a computer...)

    I'm sure some of the others will eventually come along with more accurate numbers if needed, I tend to whip through these to get "rough estimates" which is generally all I'm after! :p
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: total new, need tips and input

    Teapopper,

    As everyone above has said... "STOP"! Do not spend any money on anything solar RE related until you have defined your needs.

    Solar RE (off grid capable) produces power that is probably 5-20x more expensive than your current utility power does now...

    15 truck batteries is a relatively large battery bank. Once you purchase it, you will need a place to put it (and vent it, and water it, and SAFELY wire it, charge it, attach loads to it)...

    If you don't have a lot of electrical experience--A battery bank is an accident waiting to happen. And once you purchase it, they begin to age. You need to keep them charged and watered (maintenance), and then some sort of inverter (if AC loads to run), etc...

    Then add your location, weather, access to sun, local codes (if this is an issue), etc... And you are talking about dropping some large amounts of money for results that you will probably not be very happy with.

    I use less energy than you do (maybe 7kWH per day, have natural gas for heating/cooking/etc.) and have probably more sun (California, USA)... My Grid Tied system (no batteries) cost around $30,000 three+ years ago ($20,000 after government tax credits and rebates). An off-grid system of similar capabilities would have cost 2x as much (batteries, charge controllers, inverters, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Teapopper
    Teapopper Registered Users Posts: 13
    Re: total new, need tips and input

    Wow guys, thnx for some great answers ! That was the wakeup call i needed !

    My appartment is facing north :/, and i dont have space to store that battery bank at all.. i live in a complex with a small outdoor space with a storeromfor myself with no ventilation.
    But my goal is to reduse the bill overall, gotta change that old monitor i have too.

    Soon moving to a new house with better isolation, meanwhile ill experiment with some small solar project.

    Have a nice day all !