# Need help with new system desgin for off-grid yurt



## Aoife (Aug 18, 2013)

We bought land in Plymouth NH and just moved up last week to begin setting up our 27' colorado yurt on our property. I am not in the process of designing our off-grid solar system while my husband works on building the platform for our yurt. We have a large wood cookstove for heating but may need to run A/C occasionally in summers. As far as our power needs we will be needing the system to run:
10cuft converted chest fridge
10cuft chest freezer
2 500w desktop computers used for working
occasional charging of tablets and laptops for the kids
LED lights in the home
occasional charging of cell phones
occasional use of our centrifugal "dryer"

the AltE Store is close enough that shipping to us is lower cost or we could drive down and pick it up. 

So far I am looking at this for our set up:



https://www.altestore.com/store/Pac...d-Cabin-Package-D-560W-Kyocera-Modules/p7433/
https://www.altestore.com/store/Win...d-Power-AIR-40-12-Volt-DC-Wind-Turbine/p9620/
https://www.altestore.com/store/Win...5ft-Tilt-Up-Tower-Kit-for-Air-Turbines/p1422/
https://www.altestore.com/store/Cha...TS-60-Charge-Controller-without-Display/p807/
a top of pole mount so probably another 500 
total - 8383.53 plus 300 ship

I am looking at adding two more batteries to the setup and possibly a 5th panel either now or down the road. 

My main questions are:
Do you think this setup would be enough or effcient for the lifestyle listed above?
Are the batteries in this package good and or sufficient? We are in a pretty cold climate and it was/is attractive to ise the sealed gel for this reason alone.
Where would you tweak this setup for maximum efficiency and stay within the 9500 budget?
If this is completely the wrong direction can you offer suggestions on a good system or setup?


thank you so much for your help in advance!!! all help is invaluable and much appreciated!!

ETA we are also looking for a good generator to complement the system but are also completely new to generators as well so any help or recommendations there as well are super appreciated!


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## lynnemabry (Dec 28, 2013)

The first thing you need is an energy audit. How many hours of each thing and how much they use. Then realize what ever you plan for will not be enough. Plus, you forgot about the internet device, washer, well pump and probably many more items. 

What about your site. How much sun in dead of winter compared to summer. It seems like you never get what they say. Who is installing it? Did you plan for the high cost of wire and switches and fuses? Get a display. Otherwise you will beat up your system. 

You may need to live without a/c. And don't forget the fridge and freezer use more power in summer, a lot more. What will you do when the power is out? Any medical needs? Install the generator and that box right off the bat. Oh, and you should skip any heat making items like blow dryer, heating pad, hot glue gun, coffee maker, etc. 

You get the idea. If you are living in a yurt you are making a lifestyle choice as I am sure you know. 

These are all of my rambling of my experiences. There is a steep learning curve. There are some people that haunt these halls that have a lot of experience. I am lucky to have a capable darling and the folks here to brain pick.


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## TnAndy (Sep 15, 2005)

You see the pic with the wind turbines ?










Looks like western prairie country. They GET wind. If you've ever lived out west, you know the wind blows a LOT. AND that turbine is probably 60' in the air.

Do you get enough wind in your location to justify the expense of a wind turbine ? How do you know ? Done any kind of recorded study ? Or is the plan to just stick one up and hope for the best because you get a little breeze now and then. That ain't WIND. Unless you are SURE you get 12mph or more on a regular basis ? Put a flag out there.....does it stand straight out much of the time ? You have wind.

Otherwise, spend your money on more solar.


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## Steve_S (Feb 25, 2015)

On Wind Turbines, I'd suggest reading this First: The Truth About Small Wind Turbines

Next, BUY a Kill-A-Watt meter and check how much power you are really using ! 500W per Desktop is REALLY STEEP ! Even my own Graphics Workstation doesn't use that... With Screen, Audio system & Inkjet it averages 235w and will hit 300w when the Video demands more.
CPU	AMD FX-8320 Vishera 32nm Technology (8 core)
RAM	32.0GB Dual-Channel DDR3 @ 668MHz (9-9-9-24)
MB	ASUSTeK COMPUTER INC. M5A99X EVO R2.0 (Socket 942)	
Graphics	47LV4400 ([email protected])
2047MB NVIDIA GeForce GTX 660 (ASUStek Computer Inc)Storage
223GB TOSHIBA MKNSSDCR240GB (SSD)	
698GB Seagate ST750LX003-1AC154 (SATA)	
1862GB Western Digital WD My Passport 0820 USB Device (USB (SATA))
Optical Drives	PIONEER BD-RW BDR-208D
Audio	High Definition Audio Device​
Security: Consider that if anyone wants to break into a place, they will but a yurt offers even less challenges to get into. You may wish to consider building an Well Built strong 8x12 "utility shed" which is firmly anchored to piers and can house your solar equipment & batteries.

Energy Efficiency: Saving a watt is much cheaper than generating a watt and for every watt saved, that's more "backup" for you. AC is a major power sucker, so think that through... Fridges & freezers, especially older ones are horrible for energy frugality. There are many Energy Star fridges that use less than 300kWh per year, same for freezers.

Charge Controller: PWM or MPPT, simply put MPPT, is the only real choice to get every bit of juice you can out of your panels. That kit above already comes with an Outback FM60 which is top quality MPPT controller. Midnite, Outback, Xantrex, Tristar (Morningstar) are all top notch. There are also some very good "Value Brands" but there you have to tread carefully.

Power Inverters: There are several brands also available and a couple of things to watch for. Pure Sinewave is the only way to go if your using sensitive electronics (you are). Inverter/Chargers are more expensive but if you have a Genny you'll want the charging feature, otherwise you'll need an external charger and you lose some with that. RESEARCH a bit ! I have been told by a few "in the business" that Magnum is having a lot of warranty claims for the past yr & a bit. This bears out when you can buy refurbed Magnums readily & cheaply while not others... I would not touch a refurb personally.

Generator: Most bang for buck would be a 2000w Inverter Generator. There are many brands available to suit a variety of budgets. They are all much cheaper to run than non-inverter types, they are MUCH quieter and are relatively small and easy to handle. Key MUST HAVES: Low Oil Shutoff (not just an alert), Electric Start, CGFI Plugs, at least 5 hrs runtime on a tank. Option to "stack" them (doubling capability) if you think you may need to do so later. 

Batteries: Many camps on these guys but one thing holds in all camps... costs can be insane ! Flooded Lead Acid are still cheapest per aHr but they have their quirks and need a certain amount of attention & care. AGM which is gaining popularity are pricey @ much less aHr return. NiFe & LiIon are big bux but lifespan is longer. (still too $ steep for these).

Lastly, the 3 most expensive parts are the Controller, Inverter & Batteries. If your intending on later expansion the controller is the key component and so it may be prudent to step up now to allow for it, replacing it to upgrade can cost. The inverter is matched to the battery bank, so 12Vdc / 24Vdc etc... a typical 2000w inverter will handle a 4000w momentary demand (motors, pumps starting). Batteries, the one thing everyone talks about and has opinions on... Simply put, regardless of the type you go with, once up & running, adding more batteries reduces the lifespan / capability of the new ones to the weakest one in the set.

Hope it helps a bit.

This is just generalised stuff to be aware of and to consider. A few may argue a point or whatever but this is not "expert tech", it's simply an overview based on what I have learned over the past couple of yrs and some of the lessons others have learned along the way.


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## Aoife (Aug 18, 2013)

First off thanks for the reviews!! 

I did purchase a KillOwatt meter but it is in storage now Doh! Before we packed everything and moved up here we did run it on one of the 500w desktop PCs and if my husband's memory is right it was reading 40-50 on the meter avrg for that PC when it was running pretty much all daylight hours and shut off at 9pm. 

For more details no well or pump. We will have a gravity fed cistern setup though we may setup a DC pump to the stream on the property to run through our RO system. No washing machine though we will be running this unit to prep our clothing for line drying http://www.amazon.com/The-Laundry-Alternative-Centrifugal-Portable/dp/B002GEDBIG 

We also will have to have some form of interent so there will be 24/7 running of said modem most likely satallite. 

I have made some changes to my thought process as I have learned through reading and talking with more experienced people! I am looking into the 100w Renogy solar panels (8-10) of them, using either deep cycle marine batteries or the seemingly infamous sams club golf cart batteries. 

Now there seems to be a mild debate of hardware that I am trying to figure out. I have read so many positive things about the outback charge controllers and inverters. However I am finding a good sized group of people recommending to save money by purchasing the chinese made inverters and charge controllers on ebay. So now I am definitely confused over what is the best route for a beginner to go? Are there better places to save money so I can build a bigger system at a lower cost? 

In your opnion(s) would it be more prudent to go with the better name brands or an ebay brand true sine wave? Of the value brands that you made mention of before are there any that stand out more? I am looking to build as nice and large of a system as I can for what my budget is so we hopefully will not have to upgrade for a while. That said I am not opposed to going with more value items but not if there are logical reaons to avoid them.

On the topic of wind...... We were deciding to go this route because our area is known for good wind  in fact there are several wind farm within a few minutes of our land location. If you look on this map for instance http://rredc.nrel.gov/wind/pubs/atlas/maps/chap2/2-01m.html our location is right in a band of zone 6 power class  We do also have 2 streams on our property so later on down the line we may setup for microhydro as well.


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## Steve_S (Feb 25, 2015)

First things first. Price per Kw on panels... 100w panels are IMO a waste of time & money. Your better off building with 250w panels (60 cell) or even 300w (72 cell) but size of the bigger wattage may be an issue and can make other problems arise. 250/255 is most common "today" and best value for the dollar.

Internet & PC's... Satellite, 4/5G networks work fine (I'm on Sat). The modem, router/hub & PC's should be all turned off when not in use. Sat Modem idling is 25w average - it's keeping your phantom loads in check as phantoms cost you ! 

Water Pumping I can't address as I am still having my own battles but that is because I have a very deep well and therefore need serious pumping for that... That translates to serious bucks sadly.

Wind Power is something to consider and can be added later... Be there on the land and do proper tests. 

Renogy: Well, they are an interest bunch... 1/2 hate em, 1/2 love em. I've never used them but have read a wide variety of reviews... One thing that absolutely stands out about them, is buy from them via Amazon and not directly... Should something go wrong, they can correct it via Amazon (extra consumer backup, if ya know what I mean). If you look at this 1800W-24V-Poly-Solar-Panel-Kit-for-Cabin, this is all "good stuff" but notice there is no inverter or batteries ... They sell "House Brand" and Samlex, Samlex passes for inspection, house brand, I dunno. They are not charger types though. 

True / Pure Sine-wave inverter is a must. Charge Capable or Not affects price, personally I prefer Charge Capable for simplicity. 

MidNite Classic 150 & 200 MPPT Controllers are good and cost effective (not lite versions). The Tristar 60-MPPT is good value, feature rich and has a few extras the others generally don't. 

*A Bugaboo:*
Insurance; If you want the system to comply with regs & be insurable after inspection, all items must be at minimum UL Certified and approved. No stamping & stickers = no pass on inspection. Some insurance co's may want a pro install as well. ** If your going to connect to the grid now or in future then it's all got to be certifiable.

Value Brands:
There are many, some good, some bad, some junk and some hidden treasures. That being said, regardless of WHERE they are made, they are made according to the designers & engineers spec's, so if a they spec's a piece of junk, don't blame the guy making it... There are a few good OEM's that make things for many companies who resale under different labels. Often, Value Brands are not UL or CSA Certified and may only be CE certified (self certified by manufacturer to comply).

EPSolar from China makes reasonable charge controllers at very good prices. They are an OEM Manufacturer so you'll see them with "House Brand Labels". Here is an example on EBay EPsolar iTracer 60A MPPT NB, there are others that "look" similar but have different functionality, some more, some less. Another "brand" available that is reasonable & good value is SolarMate Solar-Mate-Charge-Controller-40-Amp-60-Amp-for-12V-24V-48V-batteries May be of Interest.

Inverter/Charger value systems... Many of these are targeted at the Vehicle / Mobile market but work fine in an off grid world. They typically are not UL/CSA Certified because of their target. Aims-PICOGLF20W24V 120V-2000-Watt-Pure-Sine-Wave-Low-Frequency-Inverter-Charger is a Good Product and may be worth looking at, more info at AIMScorp Power-Inverter-Charger These are very similar to ZODORE or PowerStar.

Batteries:
Bang for buck again, Flooded Lead Acid L-16 type, Deep Cycle, 6v, [email protected] LiIon, NiFe and the others are $$$+$$$. _Consider cost of S&H_ Yes you may find amazing advertised deals on batteries but do consider that at minimum, each one weighs in at 120 Lbs, stack up 4 or 8 of those and watch the shipping charges ! I'm somewhat particular about Rolls Surette batteries, some swear by Tojan, others love Crown. I believe right now the Crown 430's are the cheapest L16 variant. US Battery makes an L16HC-XC2 Series with thicker plates and generally more Heavy Duty for machines or their RE version RE-L16-XC2. Shop it around and see what you can find local because if you add cost+s&h from ebay or amazon you may not save as much as it appears at first. 

I hope this helps you a bit more. 

I am NOT an expert, not even close, I'm just a guy who has been researching the crud out of this for almost 2 yrs (and taken much Tylenol as a direct result) as I am building my FT Hunt Camp / Off-Grid remote cabin now. Because I'll be there FT I'm setting up 2kw's panel (8x255w), 8x 6vdc 420aHr batteries -> 24vdc bank, 3kw Pure Sine Inverter/Charger with my 7kw Genny as secondary power. As I am never attaching to grid (way too far away) I've decided on "frugal". Frugal meaning Value Products for Charge Controller & Inverter/Charger.


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## Aoife (Aug 18, 2013)

Taking notes here! We are too far for ever getting a grid tied.  I am also not the most mathematically literate person or electrically knowledgeable so this is a big learning experience for me! My main goals is getting what we need for our daily life and keeping it under the budget we have set which is a must since my husband is off work for the year while we set up our yurt and homestead.

thanks so muh for your continued help


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## Aoife (Aug 18, 2013)

OK before we sold our old way too big for us house our average kW usage as shown on our bill would come up with needing 4.76kW for a system. I would say we are cutting our usage in half as far as what we plan on using in the long run. 

Is there a way of using locally sourced batteries that we would not need to ship?


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## TnAndy (Sep 15, 2005)

What was your average use on the old bills ?


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## Aoife (Aug 18, 2013)

Aoife said:


> OK before we sold our old way too big for us house our average kW usage as shown on our bill would come up with needing 4.76kW for a system. I would say we are cutting our usage in half as far as what we plan on using in the long run.
> 
> Is there a way of using locally sourced batteries that we would not need to ship?


ok i just went through several of the stickies on another forum and started working on the actual equations given for the information that we need. Using the stickies and the information from my previous power bills I am getting 6kWh as my number with an array size of 1714w and a 24v system. does this sound more correct? On a side note this is basing off of my previous way too big for us house where we abused our electric usage LOL


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## Aoife (Aug 18, 2013)

ok with getting the 1714w for the array size that would put me at about 7 250w panels. since I am under the 2k watt mark I could go for a 24v charge controller but I've seen some people saying to size up to 48v does that sound right or should I stick at 24v?

I am now looking at the Trojan L-16-RE-B 6V, 370AH (20HR) Premium Line Flooded Battery and just investing in better batteries instead of the golf cart batteries. At 6v per battery how many batteries would I be looking at needing for a 24v system or a 48v system when through my calculations I am getting the amp hours at 1250 for 24v or 25 at 48v. I think I must have overlooked the calculations that help you figure out how many batteries you need


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## Steve_S (Feb 25, 2015)

Hi again,

Batteries:
I'd go with the highest [email protected] you can get and I believe in the L16 format the 430aHr @ 20hr is common & is available from both Crown & US Battery, Trojan has L16hg-ac & others. The more commonly found the cheaper it will be due to stock & availability. Such is what I have found anyways.

Voltage:
12V is fine for an RV or PT Cabin with small loads. Fridge, freezer, possibly AC 24V is more suitable. 48V will do just fine but at the cost of more batteries which is more $$$.
*24VDC*
2 group(s) of 4 batteries in series at 6 volts & 450 AH = 24 volt bank at 900 AH capacity.
3 group(s) of 4 batteries in series at 6 volts & 450 AH = 24 volt bank at 1350 AH capacity.
2 group(s) of 4 batteries in series at 6 volts & _600 AH_ = 24 volt bank at 1200 AH capacity.
*48VDC:* 
2 group(s) of 8 batteries in series at 6 volts & 450 AH = 48 volt bank at 900 AH capacity.
3 group(s) of 8 batteries in series at 6 volts & 450 AH = 48 volt bank at 1350 AH capacity.

This is where you have to cost out the Batteries per Ahr... If you feel a headache coming on, step outside for fresh air... This is the stuff that makes my brain hurt ;-) Also note that 48VDC Inverters & Inverter/Chargers will cost more... It's all a part of taking from Peter to pay Paul type of stuff... However you look at it, it's your bank account that's going to feel it.

Panels:
The only time you can use an "odd number" of panels, is if they are in one string. 7 Panels in one string is a lot of juice and you'll hit a wall on the controllers. Your looking at 2 strings of 4 panels for 8 panels total for either 24/48 vdc battery banks. You can try out the Midnite solar Sizing Tool to fiddle with the panel configuration to see which controller will handle it and how. Some of the other companies have similar tools but not all. 

Some other things to consider about "kits" and new builds etc... New & Off-grid means no power co installation and doing everything from scratch & factoring in your safety. 

You will need to wire grounding rods or plates for the Panels, Solar System components & your 120v AC panel. (check the local electrical code for your area)
You will need DC Disconnect @ panels & @ controller/inverter.
Fuses / Diodes panel side & inside.
You'll need an AC Panel with main disconnect. (60a Panel should be perfect)
AC Wiring, fittings and related bits.
Lightning Suppression suitable for YOUR REGION !
Many other miscellaneous bits...

These are the "Balance of system" things that need consideration... It's quite reminiscent of having a job description that has "and other related duties" clause in it, which simply put, means all the things we can't think about right now but will drop on you at some point.

Here is a good link with many tutorials, calculators and several things often missed. Some of it is not applicable to off-grid but all valuable. The Solar Planner


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## Aoife (Aug 18, 2013)

OK big crazy question here. HA My husband, when he did some previous research, really liked what he was reading on using industrial forklift batteries. We do have a local to us dealer who has a larger variety of forklift/industrial batteries so we could get more bang for our buck without worry of shipping. That said a single forklift battery is 24 volt but each model has varying AH. Would I then need to match the amp hours to my calculated 1250AH needed for a 24v system? 

this is the plaace we would be dealing with where you can see a charge with the details of the batteries:
http://gbindustrialbattery.com/Forklift_Battery_Sizes_and_Specifications_Zone15.html

I am also looking at this inverter/charger http://www.xantrex.com/power-products/inverter-chargers/freedom-sw-24v.aspx any thoughts on that for a 8-250w panel array? It does have the major appeal of the optional genstart should we need it in the long run. 

Would a pre-wired panel work better for us noobies to setup as I chttp://www.altestore.com/store/Enclosures-Electrical-Safety/Electrical-Enclosures/Combiner-Pass-Through-Boxes/Midnite-Solar-PV2-MC4-Pre-wired-combiner/p10882/ould find this one at alt e 

Now I know I will still need all the connectors wires etc. I am hoping that I can take my hypothetical system design and have the good folks over at AltE help me put together the rest of what I will need in order to hook it all up. Maybe that is wishful thinking though


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## lynnemabry (Dec 28, 2013)

I feel your headache. We had the same one when building our system. Solar is complex and involved. None of it is cheap and all of it is important. 


More thoughts from my limited experience.

Site survey. How much sun does it get in the dead of winter? 
Do you need to remove trees?
What is the plan for keeping batteries charges in the dead of winter? Just a few days of no sun will drain your batteries. They don't like that. They are expensive. Treat them well and they last longer.
Remember that just because you have 1000 Amp hours doesn't mean you get to use them. You only get to use 10-20% of it.
If you buy any fused parts, buy more fuses. 
Plan on trenching your wire if it is a long run, near trees, driveways etc. my opinion.
Don't cheap out on the wire. Use the correct size always.
Find all of your ghost loads. The tv, all of your chargers, clocks, etc can draw power when your not using them. 
Be prepared to have no power if something goes wrong. Murphy's law says that it will only happen at holidays or when you have company. Then the people, dogs and chickens eat very well as you empty the freezer. Remember that the solar store is closed for the holidays too.
Get an electric start generator, your shoulder will thank you. 
Keep track of what the display is saying and understand how that compares to what your doing. 
Get pure sine wave. Then you can use a sewing machine.
Learn to love you broom and any other manual applience. This is your excuse to never vacuum again.

Solar is not cheaper or easier but it can work very well. As you see I have no skill just experience. Solar is a great way to have power when in the middle of nowhere.


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## Aoife (Aug 18, 2013)

lynnemabry said:


> I feel your headache. We had the same one when building our system. Solar is complex and involved. None of it is cheap and all of it is important.
> 
> 
> More thoughts from my limited experience.
> ...


We are currently researching our generator too! Looking at a generac electric start with oil shutoff. 
We are not carpet people so broom all the way with us!
Definitely going pure sine wave!
the husband will be cutting out quite a few trees to give us a nice clearing to work with and lots of wood for the stove through the winter 
We use surge protectors and UPSs religiously so we can switch off strings of things with one switch so nothing will sit on if not in use. 


Generator wise one thing I am currently questioning is gas versus propane. We are in propane land up here and I need to look into possible savings and pros and cons of propane and gasoline. 

With a genset inverter/charger like the xantrex can you direct plug in an A/C gen or do you need to go D/C? It seems very silly and wastefull to invert an A/C gen back to D/C to charge batteries then back out to A/C through the inverter to power your home! Thus why I am now also looking at straight D/C generators to which come out of a different budget than the solar so we have a decent budget to deal with so we can get a good dependable generator that will serve our needs well.


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## Steve_S (Feb 25, 2015)

Quick Thought OP. A 24v Forklift pack weighs in at 1400 LBS +/- a bit. Size is roughly 3' long x 12" wide. The weakest cell in the pack will determine capacity of the rest. 

Xantrex is good stuff but at a price. 

The folks at Alt-E are terrific & know their stuff.

My own config which I am about to install looks like this:

8x CS6P-260P Canadian Solar 260W 60C Poly PV module
1x CLASSIC200 MidNite Classic-200 charge controller 200Vdc, 79A, 
4x KMR162-M Kinetic Solar Main Rail 13'6", 
8x KEC40-M Kinetic End Clamp - 40mm - with K-Nut, S.S. Bolt, Washers and Lock Washers,
12x KMC3843-M Kinetic Mid Clamp - 38 - 43mm - with K-Nut, S.S. Bolt, Washers and Lock Washers, 
16x KLB3-M Kinetic 3" "L" Bracket Kit, with K-Nut, S.S. Bolt, washer and lock washer, 
2x KHGL-TS Kinetic Alum. Ground Lug TiN Plated with Tech Screw and Serrated Washer, 
1x MNEDC-90 Midnite Solar MNEDC90 90A 150 VDC panel mount 
1x MNEDC30-300 Midnite Solar MNEDC30-300 30A 300 VDC panel mount 
1x LC4-CP 222-1 Lumberg MC4 Y connector (1) Male / (2) Female type MC4
1x LC4-CP 235-2 Lumberg MC4 Y connector (2) Male / (1) Female type MC4
1x MC4EXT 20ft MC4 Extension cable, with male and female MC4 connector 
8x S-550 Rolls Surrette S-550 battery, 6V, 428Ah/20h capacity, 
8x C2/0-12PO Battery interconnect cable #2/0, 12" 
1x HYDROVOLT HydroVolt battery hydrometer, Compaselect - the last hydrometer you will ever buy! 
1x C2/0-10PI Inverter cables #2/0, 10ft (pair) 
1x JLLN-300 Littelfuse JLLN-300 300A/300V class T fuse

From another vendor I am getting the APS3024E 3000 watt Inverter/Charger with remote control/lcd display & auto generator starter. <$600 
Reference: aps-pure-sine-wave-inverter 

All in with taxes, s&h and the futsing that goes with it as a DIY (I am electrically competent) I'm still under $8,000.00 Canadian. (Yep, I'm North of the Border).

Add another $750.00 CAD (high side) for 60A AC Panel, breakers, wires, plugs-switches, grounding plates, NMDU Underground wire, Conduit, etc...

NB: I am building a special platform to mount the panels which will allow me to adjust for seasonal tweaking. That is located 30' from where the Solar Equipment will be housed.

-- EDIT -- While I was typing & talking to suppliers, you responded LOL
- Inverter Chargers accept 120V AC from your Generator and will charge the batteries according to the config. Some have ByPass & Pass through abilities. That can allow for powering your AC & Charging batteries depending on variation.
- Generac, Honda, Yamaha, and many others make good Inverter Generators. MUST HAVES = Low Oil SHUTOFF ! Electric Start (with remote is nicer).
- Gas / LPG. Gas is fine as long as you keep it fresh, use stabilizer if in doubt. Some genny's have LPG ability and some Multi-Fuel. LPG is good as it won't "sour" and it cheap enough to keep a 40# bottle attached and you'll have heaps. NOTE that LPG is a PITA in cold winter days, so multi-fuel may be better if you get nasty cold. Start with Gas then flip to LPG when warmed up.


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## TnAndy (Sep 15, 2005)

Aoife said:


> ok i just went through several of the stickies on another forum and started working on the actual equations given for the information that we need. Using the stickies and the information from my previous power bills I am getting 6kWh as my number with an array size of 1714w and a 24v system. *does this sound more correct? *


Who knows. 

*AGAIN*, what was your previous average use ?


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## kycrawler (Sep 18, 2011)

We are off grid for 8 months now 2500 watts of panels run through outback 80 charge controllers to a xantrex 24 volt inverter charger with 12 GC 2 golf cart batteries . We don't use much power I converted a 7 cu ft freezer for a fridge . 24 v DC water pump from cistern TV 3-4 hours per week . We still run a generator a couple hours a week to top off batteries and when running the Washing machine . We are soon going to go to a dometic propane fridge Freezer combo . 


The little 2 stroke gas generators from harbor freight are your friend they run$ 89 on sale they will run 10 hours with a 500 watt load on 1 gallon of gas I just run the cheap marine 2 cycle oil from Walmart the one little generator has 250 gallons of gas run through it and all I have done to it is remove the spark arrestor on the exhaust when it gummed up with oil sludge we ran one almost all winter to keep the circulation pump running for our hot water heat without killing batteries in the cold 

We also have a Coleman 4000 watt we run for washing machine use it runs 24 hours on 5 gal of gas runs about 2 hours a week to do 3 loads of laundry 

Laundry is a major resource hog. Our standard washer uses 45 gallons of water per load of laundry . We have 5 kids and 2 adults at home . Other than laundry water use is pretty minimal if you Limit the length of showers and use a low flow shower head


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## kycrawler (Sep 18, 2011)

Also forgot to add I would go with a 48 volt system if I had it to do again I could go to 2 parallel strings of batteries instead of 3 I would also buy an outback inverter instead of the xantrex if anything were to happen to this inverter I would replace it with 48 volt In a second


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## JeepHammer (May 12, 2015)

I didn't read the entire thread, so if I cover something that someone else did, excuse me please...

I built/rebuilt starters, alternators, sold batteries to industrial places like coal and rock mines for about 10 years,
Went to 3 of the major battery manufacturers and took the classes provided, had a look at construction, ect.

And to boil it down, it's about application here...

YES, the industrial batteries will work, steel cased work fine.
You can also get a LOT of life out of 'Discarded' batteries in this field.
Just because that battery won't run underground mining equipment,
Or a fork truck for an 8 hour shift,
Doesn't mean you won't get LOW AMPERAGE demand out of that battery for years to come...

I got my first set of industrial batteries for salvage weight,
And 5 years later when they became useless to me, 
The scrap weight went up, so I actually made money on the batteries!

*IF* you have a source for batteries, then I'd say get them and run them,
Just make sure they are serviceable before you lug those heavy suckers home!

A second idea is a damaged battery.
Often times, cables/lugs come loose on industrial or commercial batteries.
This burns the factory terminal up and ruins the battery for industrial purposes.
Connection lugs are EASY to repair for solar, low amperage draw,
(It would be a catastrophe if you ever had a 350 amp draw on a solar array!)

Some times you drill into the terminal wells and install a stud into the lead,
Sometimes you simply re-pour the lead terminal post, depending on what you have for terminals.

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Some common mistakes, misconceptions, out right false hoods...

CABLES/TERMIALS will waste as much current in resistance as you will produce from panels in some cases!

With a small, balanced system, when a terminal/cable fails, it's a huge deal.
Making your own cables is always a good idea, and use the proper cable/terminals for the connection you are making.

If you make your own cables, you get EXACTLY what you need, and since this isn't a 'Wear Part' or 'Consumable', it sticks around and is worth putting some money into...

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DC (Direct Current) doesn't like long runs of wire,
So keep DC runs short.
It's MUCH BETTER to convert to AC for longer runs of wire.

--

Batteries like a temperature around 65Â°-70Â°F. to maintain the longest life span.
This has NOTHING to do with output, charge times, ect. like a lot of people go on and on about...
The LIFE SPAN of the battery will be much longer if you simply keep the batteries as cool as possible without freezing,
With the 'Optimum' around 65Â°-70Â°F.

The other thing that will keep your batteries alive MUCH longer is simple,
DISTILLED WATER, nothing else.
'City' water, and well water have dissolved solids, mostly base minerals, that neutralize the acid, or builds up on the plates in the battery.

NO CHEMICALS in the water either. 
Remember, this is an acid in that battery, and acids react to almost everything, including trace amounts of chemicals used to treat tap water.

There are watering systems that you only have to look in on, fill the tank about every month or so, these also recover your electrolyte (Acid) and return it to the battery cells.
A good investment unless you think that watching your batteries is good entertainment! 

Small wind generators are virtually worthless other than they often put a perfect final charge on batteries.
My batteries charge in the daytime, but the charge controller cuts them just a little short on charge.
That is to save the battery/cells at the ends of the battery/bank from OVERCHARGING.

My small scale wind trials found the wind charger put a very fine, slow final charge on the batteries without the risk of overcharging/overheating.

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Terminal/Battery maintenance is a pain, but it can be minimized...

Batteries produce corrosive gasses,
On top of that, there is no such thing as a 'Sealed' battery.
Acid WILL creep up the battery terminals and corrode the crap out of terminals, cables and anything else it can contact...

*DO NOT use those felt 'Neutralizer' pads on sitting placement batteries!*
You NEVER want a 'Base' that will neutralize your electrolyte 'Acid' in the batteries anywhere around the batteries!

A WEAK baking soda solution to clean the terminals OFF THE BATTERIES,
But never on the batteries themselves!
It's just too easy to get that base into the acid ruining the battery.

You are better off with stainless terminals, cadmium plated terminals, and sealing the terminals up with something that won't kill the batteries.

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USE NOTHING BUT STAINLESS BATTERY BOLTS through the terminals.
Use a BUNCH of grease/coating/anti-corrosion spray on EVEYRTHING that is in close proximity to the batteries.

There is a continuous electrical current running through those terminals, and when you stack a bunch of dissimilar metals together on the terminals,
You will create a corrosion/plating nightmare.
CARBON STEEL IS THE WORST POSSIBLE THING YOU CAN DO TO A TERMIAL.
Stainless will be the least reactive, so stainless steel bolts are fine.

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When you make battery cables,
1. CRIMP. This is a MECHANICAL CONNECTION,
It's there to physically hold the cable in the terminal,
IT IS NOT AN ELECTRICAL CONNECTION!

2. SOLDER! This is the ELECTRICAL CONNECTION.
Either silver solder, which the heat is often too much for the insulation on most copper cables,
Or use ELECTRICAL SOLDER (Rosin core, NEVER ACID CORE) solder.
Silver Bearing Solder is available, a silver content of as little as 2% will help protect your connections, and it melts fine without overheating the insulation.

3. If you use 'Flat Tubing' type terminals, make sure you SOLDER THEM SHUT!
That is a piece of tubing that has one end flattened,
Then a hole punched in it.

The gap is still there for acid to creep into the electrical connection.
This has ruined many a cable from the inside out!
A little solder INSIDE the terminal well, solder that corrosion highway closed,
Then they are fine to use.

4. HEAVY DUTY HEAT SHRINK!
Seal that connection up after soldering!
Use the kind of heat shrink that has 'Glue' in it for the best environmental seal.

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You will need to keep the AMPERAGE DOWN, and the VOLTAGE UP.
Amperage is what causes problems, and you don't need DANGEROUS amperages to get things working well...

Amperage is what burns terminals up, switching up, cooks the batteries, and causes electrical arcs that you can't stop...

I have some battery string diagrams that help illustrate this,
If you would like a link, I'd be glad to help you out...

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Since you will normally be dealing with 'Golf Cart' size batteries for Amp/Hour production, and still keeping the cost down...
(Golf cart batteries are cheap per amp hour, so they are commonly used in battery banks)
You will need to build 'Strings' or 'Banks' of batteries.
These MUST be rotated in the string from time to time,
The center batteries need to be rotated to the ends, The end batteries need to see center duty in the string...

To make my life easier, I built little 'Furniture Dolly' carts to roll my battery banks around on.
(As I get older, lugging these things around is getting harder and harder!)

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Always look for 'Hot Spots'.
Those little $20 'Temperature Guns' work great for this.
A hot spot is an undersize terminal, a failed terminal, resistance from somewhere and needs to be corrected.

If you use the CORRECT size cables, terminals, ect. there should never be a 'Hot Spot' in the wiring.

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Consider REDUNDANCY & LOAD SHARING INVERTERS. ('Ganging')
Yes, running TWO inverters is going to waste a little current,
but spreading the load out over TWO inverters means they work HALF AS HARD...

That also means if one fails, the other one picks up the load, no interruption in service.

I have found out over the past 12 years that inverters last MUCH LONGER if you keep them to about 70% capacity or less.
Inverters are expensive to buy, they are expensive to repair.
Every once in a while you will run into used ones on Ebay or other sales places,
but most times people know EXACTLY what they have and what it's worth...

If you DO NOT want to be without power, then buy your back up inverter now,
Or use a spread load (Ganged) inverters.

--

Depending on how handy you are and what kind of weather you see,
Consider sun tracking mounts for the PV panels.
Sun tracking kept me from having to buy half again as many panels as we scaled up.
This is MUCH easier to do than you think, and you DO NOT have to use those expensive & wobbly post mounts the panel retailers are trying to sell.

Anything that ROTATES to follow the sun will keep your panels in 'Peak Sun' for longer throughout the day,
So the panels simply produce more raw current.

The rotating post can be as simple as a pickup truck axle with one end set in concrete. This is a VERY stable platform, and it's CHEAP, solid as a rock, has bearings to rotate the load on...


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