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herringcove
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# Posted: 19 Sep 2013 13:41
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Hi there 
I'm fairly new to off grid living and am looking for some expert advise.
We just moved to a beautiful off grid home in Nova Scotia. The house was designed mainly for summer use and our task now is to upgrade it to live in all year round. The house is out on a cove and does have good sun exposure. It's not very big, approximately 15'x40' in dimension and came with a small 30watt solar pv and 12V battery (which is now dead!). We plan to design a new system to give us enough energy to power lights, pc and small electrical appliances. Fridge and cooking stove is by propane and heating is by wood stove and propane water boiler.
I've done a calculation and we roughly need 3kwh per day. We don't have a huge budget to spend (about $5k or slightly more) but on the other hand I know it is more cost effective to design a good system from the beginning, as would benefit us in the future.
So here's my suggestion for our solar setup;
6x Kyocera 215 watt panels
Outback FM60 charge controller
Magnum Energy MS4024, 4000watts 24V Pure Sine Wave Inverter or
Outback VFX3524M, 3500watts, 24V True Sine Wave Inverter???
Is any of units mentioned above overkill??
This is where I need some help.  Which deep cycle battery manufacturer do I go for??? It would be best if it was maintenance free (AGM I suppose?). I thinking of having 4x 6V batteries in series for 24VDC.
We also picked up a second hand generator from a neighbor. It has 3650watt max output. We could use this as backup to charge batteries when required. Someone also suggested a Generac Ecogen propane generator, which sounds like a good setup but only in the future as it costs $4k!
All suggestions are highly appreciated!
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Just
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# Posted: 19 Sep 2013 16:44
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Most here use lead acid golf cart batteries last longer easy to care for. They have them at CTC or Cosco in Canada or on line but the shipping charge for batteries is very high. I have 2, deep cell , lead acid,140 amp hr. batteries from walmart 7 years old work for me but, I only have a small occasional use cabin. your plan looks solid to me but there are others here who are good at bigger systems .I'm sure they will have a look ..
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Rossman
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# Posted: 19 Sep 2013 17:02
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Quoting: herringcove Which deep cycle battery manufacturer do I go for???
I'd vote for Trojan or Surrette!
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GomerPile
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# Posted: 19 Sep 2013 17:42
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3500-4000 watts of inverter and 1200W of solar seems like a lot. The stuff you want to power are "lights, pc and small electrical appliances."
Lights, make them LED and you will be using about 8W each.
PC, if you need a tower for work or something, ok....otherwise a laptop draws 60 watts.
DSL = 6 watts
19 inch LED TV = 36 watts +/-
Toaster = 700-800W
Small Microwave = 800W
Do you have a well pump?
I would make a much better power inventory before spending any money. I would also think about what you *really* need vs what you want. A 1200W microwave is nice, but if a 800W cooks the stuff you need it to, then why buy a power system that is 400W larger?
Just some random thought to get you thinking...
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razmichael
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# Posted: 19 Sep 2013 18:48
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Suggest you also do a detailed solar analysis if not done already. NS in winter when you also need more lights may point to more batteries to get you through days of lousy weather or plan on lots of generator time. You don't mention how the cabin is wired - all 120?
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MtnDon
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# Posted: 19 Sep 2013 19:56
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Quoting: herringcove Outback FM60 charge controller Magnum Energy MS4024, 4000watts 24V Pure Sine Wave Inverter or Outback VFX3524M, 3500watts, 24V True Sine Wave Inverter???
Good equipment. I would go with the Outback inverter as well as then the Mate unit (that is needed to program the inverter) can also be tied to the FM60. That gives you a remote that can be inside and placed conveniently. Of course I am biased as I have that exact same equipment. Also a good choice going 24 VDC, IMO.
Depending on just how much power you use the battery capacity might be low when compared to the PV array size. We have half the PV watts but double your battery capacity, but also twice+ the sun (New Mexico). We do use more power than many folks though.
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creeky
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# Posted: 20 Sep 2013 10:13 - Edited by: creeky
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The Schnieder/xantrax inverter chargers look pretty good. and they're fairly reasonable in price.
I personally have a Ramsond pure sine 3kw inverter and a separate PowerMax 75 amp charger. I have to charge manually, but as I only use it in Dec/Jan. it's not too onerous a chore. And the net cost, taxes and shipping in, was under $800.
As MtnDon suggests. With that much solar you might want 800 amp hrs at 24 volts battery capacity. This would allow you to use an electric fridge. Saves quite a bit of money on propane/fridge purchase.
For batteries I like the Crown batteries. They have a new line of RE batteries. As Just pointed out, lead acid for off grid is the way to go. The brand depends more on your local battery supplier.
I also vote for the morningstar mppt 60. Comes with internet connection/programming and lightning protection built in. At $500 it's really hard to beat.
Finally, I have 48v panels (installing my second kw this fall). There are a variety of advantages, primarily they cost less per watt. And the higher voltage allows the use of thinner wire. Your mppt solar controller will regulate the power if you have a 12/24v battery pack.
48 volt battery packs have some efficiency advantages, particularly if you have to place your panels a long way from the batteries (See Morningstars new 600v! solar controller). But I like 12 and 24 for the lower cost of adding accessories (power chargers, DC direct devices, etc).
Have I made things easier? 
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herringcove
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# Posted: 20 Sep 2013 14:56
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Thank you all for your insights!
Creeky- yes u have made it easier!! if let's say a 6V battery has 200AH, would 4 of these batteries in a series give me 800AH?
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suburbancowboy
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# Posted: 20 Sep 2013 15:23
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According to outbacks sizing tool. FM60 will not handle your 6 panels.
You would need to go with the next size up or go midnight solar. By the way if you are set on the FM60 Solar Electric has them on sale for 470 something with free shipping now. I ordered on last week. I am going with 3 250 watt panels and 8 6 volt batteries.
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razmichael
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# Posted: 20 Sep 2013 16:12
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Quoting: herringcove f let's say a 6V battery has 200AH, would 4 of these batteries in a series give me 800AH?
Afraid not. In series adds up the voltage, in parallel increases the amperage. If you put all four in series you get 24 volts at 200ahs. For 12 volts you mix series and parallel for 12V at 400ahs. Don't forget however that although the amperage stays at 200 (assuming you want a 24V system) the watts are the same as 12 volts at 400amph. When comparing the capacity to your draw at 120VAC you need to convert to compare apples to apples.
Generally consider only half of this available maximum (50% draw). check out the 12 volt side of life part one and two - slightly dated but great basic information. Part 1
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creeky
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# Posted: 21 Sep 2013 10:51 - Edited by: creeky
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razmichael is correct. at 200 amp/hrs and 6v you would need 16 batteries. Most RE batteries are in 400 amp/hr range though. So 8 400 amp hr batteries would do you nicely.
About sizing: I have a 1kw of panels and a 12v battery bank. And I have the Morningstar 60 amp controller. So the theoretical maximum is 750 watts. However, humidity, cloud cover, a hatch of ants ... all will block the sun. So having too much panel is actually a good idea. On cloudy/humid days you will be making more power because you have more panels. Where i live the fall is quite cloudy. I like having extra panel space. Today is a classic example. yesterday at this time I was making 650 watts. Today it's raining, I'm making 20 watts. On a bright cloudy day in winter I might be making 300 watts. I'd only be making 225 with 750 watts of panels. Getting 5 hrs of bright cloud means I'll make close to 500 extra watts. In the winter you will be very happy about this. Of course, make sure your solar controller reliably supports "current limiting" like the Morningstar.
Also 20-30% is the suggested draw for a full time offgrid battery system. So if your 24v system has 800 amp hrs you have 19200 watts of stored power. Now you can use 6000 watts. If you think about three dark cloudy days in a row. It means you're using 2kw a day. It'll run the fridge and lights but no tv marathons for you.
The reason you want to keep draw %s low is basically lifespan. Studies show you can draw your batteries down 80% 300 times. So your batteries last a year. If you want your batteries to last 8-10 years, you have to keep the depletion % in the 20% range.
There are so many variables here. I guess it comes down to buy what you can afford and then tailor your loads accordingly. The forum at Northern Arizona Wind and Sun is an excellent place to do research for your system.
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herringcove
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# Posted: 22 Sep 2013 17:41
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razmichael & creeky thanks for the input!!!
Creeky I see you have a 12v battery bank. I'm thinking of a 24v bank as I've read that it is more efficient etc. Any thoughts if I'd be better with a 12v bank?
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razmichael
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# Posted: 22 Sep 2013 18:05
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I'm not clear on how you want to wire the house (or how it is wired). Is the intent to have the house all 120AC through the inverter or a mix of DC and AC? The advantage of higher voltage is mostly the reduced voltage drop (tied with less need for heavier wiring - this applies throughout the system including from the batteries to the inverter which are very heavy gauge). Disadvantage is if you intend to run DC mostly it is much cheaper to get 12V stuff than 24 or 48 (at least from what I have seen). Another advantage for a higher voltage is that it can be easier to wire the batteries and most èxperts`suggest that anytime you wire in parallel you run a risk of not charging evenly (there are some really good sites to explain how to wire to reduce this problem). Here is one site that explains some tricks Wiring Batteries.
Given the large solar bank you are planning to use I would think most people would suggest 24 volts at least but I think it may help to better understand how you intend to wire the house, how far from the house are the panels etc.
Disclaimer - I have used 12 volts throughout my cabin but it is only for lights and water pump with an inverter for the occasional vacuuming or hair dryer (my wife insists on this). With the amount of power you I would consider if the easiest route is just to go 120 throughout - easier wiring, lots of LED lights available, standard switches etc.
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MtnDon
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# Posted: 23 Sep 2013 19:15 - Edited by: MtnDon
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Quoting: razmichael The advantage of higher voltage is mostly the reduced voltage drop
24 volt battery system also allows twice the watts to be handled by the charge controller, compared to a 12 volt system. Check the specs on the FM 60/80 to see
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creeky
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# Posted: 24 Sep 2013 09:49
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as per razmichael: I wouldn't bother wiring for dc. Just go straight ac from the inverter. you''re a full-timer. If you have a system under 500 watts or so, then a dc line makes sense for lights and to power some kinds of devices.
but over that, you're running ac for something so you might as well just stay on that route and forget double wiring etc. my two cents and some may disagree.
I made a mistake with my 12 volt battery bank. I had a trailer at the time and it was 12 volts. eh. everybody makes mistakes and it hasn't turned out too badly for me. everything works. and i saved some money on the inverter / charger. two more batteries and a 24 volt inverter would save me some upgrade costs tho.
never the less. i recommend 24 and if I was a full-timer (and I am) and I had to put my batteries a long way from my panels I would be looking at a 48v system for sure. there's lots of new toys coming to the solar market and they start at 48v. The new morningstar controller even supports 120 v battery bank and 600v at the panels. Now that's amazing.
my next upgrade, not until 2015, will be 48v at least. things have changed a lot in the three years i've been running my system. the new Schnieder inverters are the same price at 48v as at 12. Most of the rest of the gear needed is the same at 48v. when i built my system 48v over 12 was double or more.
so when you price out your system look hard at 48v is all I'm sayin'.
remember. most of us have older systems that we love because they've been taking care of us for years! but there's some new stuff out there. so...
oh. and have i mentioned. morningstar controllers rule. 
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herringcove
Member
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# Posted: 30 Sep 2013 09:51
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 thanks!! I think 24V battery system is the way to go!!
I've just been speaking to an off-grid specialist and according to him a 3kwh system with 3 days capacity is going to cost more like $15k. That's pretty shocking numbers!  Just wondering if there's something I'm missing here?
Is it likely that a pure sine wave inverter may cause trouble with our exiting 3650 watt generator by not accepting the current? If yes, is there a way to avoid this?
We have some electrical appliances from the UK that we would like to use. Those have 230V output. I had a look at the Xantrex XW4024 Inverter charger that has both 120/240VAC. Does this mean I can run both 120V & 240V at the same time? Otherwise is there an accessory that can be add to a 120V inverter to step up to 240V?
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creeky
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# Posted: 30 Sep 2013 10:16
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why 3 kw? you were originally looking at a 1.5kw.
Schnieder/Xantrax inverter-charger 1500
1.5 kw panels 1500
Morningstar controller 600
8 400 amp/hr batteries 2400 (I'm guessing 300 ea.)
wires/fuses/disconnects 1000
?fuss and bother 1000?
you could double your panels with another controller and more panels. add 2100.
no. your inverter doesn't care about your generator.
Leave the UK electric appliances at home. UK appliances use both a different voltage and frequency (230/50).
Yes. you can have both 120 and 240 at the same time.
good luck.
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razmichael
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# Posted: 30 Sep 2013 10:23 - Edited by: razmichael
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Creeky beat me to it - Quoting: herringcove We plan to design a new system to give us enough energy to power lights, pc and small electrical appliances. Fridge and cooking stove is by propane and heating is by wood stove and propane water boiler
Maybe you need to step back and take another look at your needs (based on your initial statement). And, again, as Creeky states, the 240AC from the inverter is not the same as the UK 230/50 cycle. You could get step up transformers to step the 120/60 to 230/50 for the appliances but - buy US appliances!
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herringcove
Member
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# Posted: 30 Sep 2013 10:45
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Ooppsss...I meant 1.5kwh!
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herringcove
Member
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# Posted: 30 Sep 2013 10:53
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Please ignore above message!
Quoting: herringcove I've done a calculation and we roughly need 3kwh per day.
I am looking for 3kwh/day
Quoting: creeky Schnieder/Xantrax inverter-charger 1500 1.5 kw panels 1500 Morningstar controller 600 8 400 amp/hr batteries 2400 (I'm guessing 300 ea.) wires/fuses/disconnects 1000 ?fuss and bother 1000?
So in total we are looking at about $8k That's probably right from all the reserach I've done. Good to know as I'm no electrician...and there may be hidden cost I was unaware of!
Quoting: razmichael You could get step up transformers to step the 120/60 to 230/50 for the appliances but - buy US appliances!
I think step up transformers is probably the answer! Will check them out to see if they are any good...
Thanks guys!
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razmichael
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# Posted: 30 Sep 2013 10:53
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herringcove, I mentioned this earlier - how is the house wired now? I ask because you state it is off-grid now with a very small PV system and you plan to take it from a summer house to full time. You are talking about a much larger system, primarily 120VAC. If the house is wired for AC now then connecting in an inverter to a panel is not a problem. On the other hand, if it is just wired for a few DC lights and you plan to wire it for AC then this will potentially substantially change your cost estimates.
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razmichael
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# Posted: 30 Sep 2013 10:55
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Quoting: herringcove I think step up transformers is probably the answer!
Personally, although I mentioned them, I also strongly suggested you buy new appliances and not use them!
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herringcove
Member
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# Posted: 30 Sep 2013 10:56
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Quoting: razmichael how is the house wired now?
I believe it is wired for AC now. We do run a generator at night and all the power sockets seem to be working. Does this answer your question?
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razmichael
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# Posted: 30 Sep 2013 10:57
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Quoting: herringcove Does this answer your question
Yep. Just checking.
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FullSpectrumSurvivalist
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# Posted: 24 Oct 2013 16:01
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Quoting: GomerPile PC, if you need a tower for work or something, ok....otherwise a laptop draws 60 watts.
That depends on the laptop, mine uses closer to 200 watts at full throttle than it does 60 watts. I agree though get a laptop that is powerful enough to do what you need it to do and it will be both portable and use less power than a comparable tower will.
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MPL
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# Posted: 18 Dec 2013 19:23
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Batteries - Concorde or UPG are fairly priced
Concorde 12v (sealed lead acid), (212 aH) $ 500.00 + ship
UPG UB-4D, 12v (sealed lead acid), (200 aH) $ 400.00 + ship
The Magnum Energy product is a very good unit.
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