Building a new off grid house in wyoming need help!

myhouse07 · August 2010

I am building a house in cheyenne wyoming I have built many house but this will be the first of what I hope to be many off the grid home's. I will live in this one with my wife and 4 kids. The home is going to be over 4,000 sqft. It will be on a well and the well only puts out 25gal a hr. the well has a High eff. 220v pump it has a soft start and only pulls 8 amp. it will pump to a in house 600gal. cictern on a timer to run only 4 times a day for 20 min. as need.
Our power goal is to use only 6 to 7kw a day. I am planing for 10kw,

What I am thinking of using as of now.
5kw of Evergreen ES-A-195watt
Xantrex Inverter-XW6048
TWO Charge controllers -XW-MPPT60-150 (maybe the MidNite Solar Classic 150)
Perkins 10 kW Diesel Generator

Ok here is the hard part for me. Was thinking of using 16 sam club 225Ah 6V GC batterys to make 2- 48v banks, one bank to each charge controllers? Why the cheap batterys? There only 86 bucks out the door and wight 4 lbs more the the t-105. I know I will be discharging them 50% a day and have no back up. But was thinking thats what the perkins is for it would only have to run 2 hrs on a bad day right ?
I really need battery input ? why is it bad to use more the 2 strings? If I used 32 sam club 225ah 6v gc batterys to make 2-48v banks @ 450aH each ?
I can buy 16 370ah 6v batteys but there 300 buck each will they last 3 times long the the sams club one's ? And what if in 2 years they have the Li-Ion Battery ready ?

Cariboocoot · August 2010

Re: Building a new off grid house in wyoming need help!

No offense but, you really need to re-think this whole thing.
To start with, 6-7 kilowatt hours per day is massive for an off-grid home. Every $ you can spend on reducing your usage will save you twice that in production costs. No kidding. Most of us off-gridders get by on less than 1/2 what you are planning.

Your well pump is a big user, as you already know. Since you have a low recovery rate and are planning on using a cistern, consider a direct-solar pump. Check out this section of NAWS and see if you can find something suitable: http://store.solar-electric.com/sun-pumps.html
Yes, they're expensive. But they can run on varying amounts of direct solar power; sun shines, pump pumps and fills the cistern. Then you'd only need a small pressure pump to charge the house system.

As for the batteries you specifically ask about ... the larger the bank in Amp hour capacity, the more you'd want to go with 2 Volt cells rather than 6. You end up with fewer connections between batteries and fewer cells to check for the same amount of power. The more connections = the more things to go wrong. Not the least of which is current not flowing evenly in and out of each battery, leading to loss of functional capacity and premature battery failure.

No matter what you go with for batteries, you ideally want it to be "all one bank". So if it needs two charge controllers you just hook them both up to the same spot; there is no problem with paralleling controllers.

But first, I think you should work on getting your loads down. You need to size the inverter and battery bank according to the load potential (and btw 50% DOD is a maximum - you should try for less) and then size the array and charge controllers according to the battery bank size.

I'm a little confused about your battery plan, but it looks like 450 Amp hours @ 48 Volts. That's a maximum of 10 kW all right, and could easily be recharged off 5kW of panels. In fact, depending on your sun you could get away with less. Since you're in Wyoming, it's a very good idea to have more.

And a back-up generator.

Wait for it: there will be more responses with more suggestions!

myhouse07 · August 2010

Re: Building a new off grid house in wyoming need help!

Thank you for input I will never take offense:D
2v battery would be nice but they cost big bucks. besides 48V devied by 2V is 24 batterys ? 16- 6v batterys is less connections between batteries. I dont mind spending money on things that last. but batterys just go down hill. I need lots of power for radent heat pumps and solar hot water pumps. right now I am looking at only $25,000 for my set-up and have a $10,000 grant. So $15,000 is less then a grid hook up.

Here in Cheyenne Wyoming we get a avg. of 6 hr sun a day. This may be a dumb qweston but will I use power from the batterys when the sun is out? if I have 5Kw of solar panls. I would think I would be charging batterys and have power to run the house too ?

icarus · August 2010

Re: Building a new off grid house in wyoming need help!

The equation is pretty simple, the execution is what gets complicated.

If you figure out your loads as close as possible, cutting out anything that can be accomplished with other energy sources easily you come up with a daily average KWH load.

My basic rule of thumb is, if you take the name plate rating of your PV, divide that in half to account for ALL system loses, then multiply that number by 4 which represents the number of hours of GOOD sun one can reasonably expect on average over the course of the year. (Most folks over estimate the amount of sun they really get, at the same time they under estimate the loads, leading to a system that does not perform as expected.

So whether or not you use power during the day from the batteries or at night is largely academic, it is the net power used and the net power produced that counts. Remember that a battery based system has much bigger system losses than grid tie system. A grid tie might near 80% while a battery based system is lucky to be 55%.

So in your case, 5kw/2=2.5kw*6=15kwh/day available net/net out of the inverter. That is using your provided 6 hour number. Personally, I would be more comfortable using 4 hours as an average, especially if you are going to be full time. So that number would be 5/2*4=10kwh/day. So add up you expected loads, and see if you can get them in under 10kwh/day. This the assumes no reserve, and most of us suggest a system that is big enough to go 2-3 days without real sun, and then can recharge in a day or so, or you will have to use the genny. Personally, I also feel that if you draw your batteries to ~50% SOC every day, they are not going to last very long. My ideal is 20% DoD, and a max of ~30% on any routine basis.

One other often overlooked aspect of battery based systems is that when the batteries come closer to full, the charge controller will dial down the charge current, resulting in leaving available power "on the table". One way to combat this, is to save as much of your loads for when you have the batteries nearly full, to take advantage of this excess power. Laundry, water pumping, shop work etc.

The bottom line is, if you have grid power available, it will be way cheaper per KWH than battery based, by a factor of about 4. Off grid costs ~ twice as much to install (and the batteries have a very finite life!) and they run way less efficiently, resulting in ~ 4 times the cost. Figure out what the grid connection will cost, and see if it really makes sense for you to do off grid.

If you haven't read these links before, I strongly suggest doing so:

http://www.batteryfaq.org/
http://www.windsun.com/Batteries/Battery_FAQ.htm#Lifespan%20of%20Batteries

Good luck, welcome to the forum and keep in touch,

Tony

PS We live off grid, with ~400 watts of PV We use ~ .6kwh/day, and probably make ~1kwh. The extra goes to load shifting and reserve for cloudy days.

Ralph Day · August 2010

Re: Building a new off grid house in wyoming need help!

Marc and Tony are exceptional in their control of loads off grid. My setup sounds much like yours, but with 2.1kw pv, 1kw wind turbine and 10kw genset. Before going off grid I was down to 7kwh per day. Living off grid for 6 years has shown it can be done with less...my genset would only run for 120-150 hours per year, mostly in the gloomy times of Nov-January.

It's not your loads that will kill/sour a project, but the quality of the infrastructure, read batteries! If you're going to do this either take the often quoted "golf cart batteries to learn on" view and expect to replace them in a few years with a premium set.

Good luck

Ralph

Dave Angelini · August 2010

Re: Building a new off grid house in wyoming need help!

Do it right the first time! Big systems and new users that need over 5KWH per day have a much higher chance of failure. You must plan on using less energy!
Better start cutting that firewood if it is going to be this winter!

Dave Angelini · August 2010

Re: Building a new off grid house in wyoming need help!

myhouse07 wrote: »

Thank you for input I will never take offense:D
2v battery would be nice but they cost big bucks. besides 48V devied by 2V is 24 batterys ? 16- 6v batterys is less connections between batteries. I dont mind spending money on things that last. but batterys just go down hill. I need lots of power for radent heat pumps and solar hot water pumps. right now I am looking at only $25,000 for my set-up and have a $10,000 grant. So $15,000 is less then a grid hook up.

Here in Cheyenne Wyoming we get a avg. of 6 hr sun a day. This may be a dumb qweston but will I use power from the batterys when the sun is out? if I have 5Kw of solar panls. I would think I would be charging batterys and have power to run the house too ?

I just read this one! Do yourself a favor and connect to the grid! If you even are twice the cost you will save your family alot of grief. I have done systems for people in your neck of the woods and there is no way to make sense of the money part unless the land is remote from power and you have to be there!

Solar Guppy · August 2010

Re: Building a new off grid house in wyoming need help!

I stopped reading at 4000sf and 6 full time residents ...

If your expecting to heat/cool plus all the electronic toys ( tv/computer/sat ect ) ... your looking at easily 50-75kw day for actual usage and for a typical home that's not allot

Now the two true off gridders that responded probably have 1/5th the square footage and less residents hanging around to consume energy.

You can build a power plant to run your heat pump , refrigerator, freezer, washer dryer, water heater, well pump, computers tvs etc ... but it will be a 6 figure system and no, wall-mart batteries won't be the choice for storage

Get the grid connected to the 4000sf home or rethink the home size but I suspect your other 5 residents haven't been informed of what changes will be required to be off grid

BB. · August 2010

Re: Building a new off grid house in wyoming need help!

Just to give you an idea of what 10kWH per day would look like for an off-grid system in Cheyenne Wyoming using PV Watts website to estimate...

Use 1kW of solar panels (nice round number), 0.52 derating factor (solar panel to useful 120/240 VAC power), fixed array tilted to latitude:

"Station Identification"
"City:","Cheyenne"
"State:","Wyoming"
"Lat (deg N):", 41.15
"Long (deg W):", 104.82
"Elev (m): ", 1872
"PV System Specifications"
"DC Rating:"," 1.0 kW"
"DC to AC Derate Factor:"," 0.520"
"AC Rating:"," 0.5 kW"
"Array Type: Fixed Tilt"
"Array Tilt:"," 41.2"
"Array Azimuth:","180.0"

"Energy Specifications"
"Cost of Electricity:"," 7.2 cents/kWh"

"Results"
"Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
1, 4.14, 69, 4.97
2, 4.93, 73, 5.26
3, 5.67, 93, 6.70
4, 5.86, 88, 6.34
5, 5.82, 87, 6.26
6, 6.24, 86, 6.19
7, 5.96, 84, 6.05
8, 6.12, 87, 6.26
9, 6.20, 88, 6.34
10, 5.40, 83, 5.98
11, 4.46, 69, 4.97
12, 3.79, 62, 4.46
"Year", 5.38, 968, 69.70

So, you would get ~62 (December) to 93 (March) kWH per month per 1,000 watts of solar panels... Assume that you will use a generator for 3 months of the year (low sun, poor weather)... The 4th lowest month is 73 kWH per month (February) per 1,000 watts of panels:

73 kWH per month / 29 days for Feb = 2.517 kWH per 1,000 watts of panels average in February
10kW per day / 2.517 kWH per day per 1,000 watts of panels = 3,973 Watts of Solar panels

Battery wise, we like to recommend 3 days of no-sun and 50% maximum discharge (for long life). Assuming 0.85 inverter efficiency and 10kWH per day with a 48 volt battery bank:

10,000 Watts * 3 days * 1/0.50 max discharge * 1/0.77 * 1/48 volt bank = 1,471 AH battery bank @ 48 volts

For Solar Panels, perhaps ~20x Kyocera KD210GX-LPU 210 Watt Solar Panel

This would be a nice charge controller (you might get away with just one 60 Amp controller--pretty close): Morningstar TriStar 60 amp MPPT solar charge controller

And here is a good Hybrid Inverter System (good for Grid Tied and Off Grid systems): Xantrex XW6048-120/240-60 Hybrid Inverter-Charger

Perhaps 12x of these batteries Surrette 4-KS-25PS 1350 Amp-Hour, 4 Volt

Or, 48x using these batteries Trojan L16RE-2V 1110 AH 2-Volt Deep Cycle Battery

And add many thousands more wiring, mounts, pre-wired box for your power center, etc...

Roughly, Grid power is around $0.10 to $0.20 per kWH--Off-Grid Solar Power--roughly $1 to $2+ per kWH... Or 10x the cost of grid power (you have to buy and maintain the equipment, and the battery banks--plus ~1-2 additional battery bank replacements over a 20 year period).

Note--I am not in the solar business or associated with our host (NAWS) other than volunteering here (with Niel) as moderators (mostly for spam patrol). The above are just suggested starting points. There is still more work to be done to design/configure your system to meet your requirements.

We are a pretty cheap and practical lot here--We don't want to see anyone spend more than the have too for their projects.

A good number to aim for is ~100 kWH per month or less... You are are planning on ~300 kWH per month--Not much power as the typical North American Home goes--but it is a lot for off-grid.

What you are asking for is certainly possible--Just want to make sure that you have all of the basic facts for your decision.

-Bill

AntronX · August 2010

Re: Building a new off grid house in wyoming need help!

How much for grid connection? Cost per KWh? PV ground mounted or on the roof? Array distance from charge controller? How much KWh per day for your heavy loads? How much KWh per day for loads total? Does your area get tornadoes, hailstorms? Why off-grid? For independence / enviro reasons or to save money? Are you willing to pay much more for off-grid electricity versus grid power? Is this your first off-grid PV project?

myhouse07 · August 2010

Re: Building a new off grid house in wyoming need help!

Thanks you for all your help.
Right now the wife, me and the 4 kids only use 450kW a month but we have a ele. water heater and old appliances and the house is over 3000 sqft. so I know it can be done. The new house will have R 28 in the walls and R48 in the ceiling it will be heated with a high effecent boiler with in floor radent heat. The water pump are low watt olny like 15 to 25watt. I am not going off grid to save money but to help in a little way to save the world. With CF- lights and LED TVs and LED lights and high effecent appliances solar hot water heat and LP gas boiler back up I think we can do it and show ppl it can be done.

icarus · August 2010

Re: Building a new off grid house in wyoming need help!

It does beg the question however, why do you wish to be off grid, knowing it comes at twice the price and ~1/2 the efficiency? IMHO, showing people it can be done should include showing people the efficient way to do things as well.

The reality is the grid is a very great, very reliable resource and in some ways not to use it (assuming it is available) seems sort of self defeating.

Just one person's opinion,

Tony

PS All that said, if you are down to ~15kwh with a family of 6 with electric water heat you are on the right track! My guess is that ~2-4kwh of that is water heat.

AntronX · August 2010

Re: Building a new off grid house in wyoming need help!

You would offset more greenhouse gases by getting your solar grid-tied and driving an electric car (if you drive). Lead-acid batteries require fossil energy for manufacturing, delivery and recycling / disposal. There is a good chance that they have a negative EROI, even if used in solar system. Your money would have more of an effect on the environment if invested in large utility scale solar / wind project, or even better if spent on a Nuclear power plant.

Mangas · August 2010

Re: Building a new off grid house in wyoming need help!

I have a large off grid system in its sixth year. Our remote Rastra constructed ranch house is over 4,000 square feet.

After judicious conservation measures to do it right for a reliable system, you will probably spend close to 75K + with propane heat, back up genset, assuming A/C, mandatory high end wiring and civil work.

Not dissuade anyone but to do things reliably and minimize the headaches it's best to build some over capacity into a project such as yours.

My opinion.

myhouse07 · August 2010

Re: Building a new off grid house in wyoming need help!

AntronX- batterys are green and ele. car use batterys too! Here in wyoming we make 25% of the US power with coal power plants and we mine the other 65% of the coal for the rest of the US power plant. The train tracks down the street from my house move over 50 billion tons of coal a year. So dont tell me whats green or not! What goes up must come down!

BB. Thanks for the input, your info is great. Most of the ppl on here make good ponts.

I am still going to build a off-grid house. The big down fall is the batterys but with the EV cars coming out in 2012 I think battery's will get better and better.

Back to the battery bank. If I use 3- 48V strings of the sam 6V 225 Ah batterys that would make a 48v- 675Ah bank for only $2064.00 out the door tax and all. If I took 10Kw out of the bank it would only 34% right?

I am looking at it this way if the batteys only make it 2 years thats only $86 a month.

Lets say eveything but the wiring and the PV gose bad in 2 years thats only $250 a month not a big price to pay to help make the world a little better.

In my mind to be hooked up to the grid is to support the burning of coal. Even if your PV is sized to mach the grid your still using the grid at night.

Thanks for all the help.

BB. · August 2010

Re: Building a new off grid house in wyoming need help!

In the end, your system will revolve around the battery bank... It is the only think in your system whose life is directly connected to how it is treated... Towards that end, read up on a couple battery FAQs:

Deep Cycle Battery FAQ
www.batteryfaq.org

Making your first bank from a set of "cheap" batteries is done frequently--Your "training battery" bank.

One question is what is the maximum continuous power you are planning on your inverter supporting... A 48v- 675Ah battery bank is will barely support a 6kW inverter at maximum load... And it would be better if you stayed well below 6kW for your sustained loads.

If you make a bank out of parallel battery strings... You should review this link for how to best wire them so they share loads/charging current:

www.smartgauge.co.uk/batt_con.html

Also, each battery string should have its own series protection fuse to limit short circuit current anywhere in the bank (fuses/breakers/switches for large DC loads is not a trivial issue. It is expensive and not easy to do it right).

In the end, yes, you can do what you are suggesting... You will learn a lot as you go through the next 2-3 years on your first bank.

Depending on how the average weather is for your place--you may end up having to use the genset a lot during the non-winter times as you do not have the "luxury" of waiting out 3 days of bad weather for your solar array to recharge the bank.

By the way, look into Battery Monitors (and Victron brand monitors) for your battery system--I think they make the day to day battery monitoring a lot easier... Especially for the kids who did not have to buy the bank in the first place.

If you want to try something entirely different for your battery bank--These are the "high tech" alternative to Lead Acid:

Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

-Bill

russ · August 2010

Re: Building a new off grid house in wyoming need help!

AntronX is 100% correct - Anyone can do anything they choose to but please don't kid yourself it is more green to dump money down a rathole.

The community power projects, I think I just read of one in your general area, are far more green than individual units when there is a grid available.

Or one could just buy 'green' power by paying a premium. The favorite method of the Volvo/Audi drivers from the big green organizations. Does nothing at all but make them feel good.

Wilis · August 2010

Re: Building a new off grid house in wyoming need help!

Before you buy the Sam's batteries I would check with the local golf cart company. In Chattanooga I am able to buy T105’s at $101.00 + core of $15.00. Their sales are down and a small sale is better then none. Might save a little on batteries and the Trojans are good batteries. Wilis :roll:

icarus · August 2010

Re: Building a new off grid house in wyoming need help!

Sorry, not be beat a dead horse as you have already made up your mind it seems. That said, I take issue with this statement:

"Lets say eveything but the wiring and the PV gose bad in 2 years thats only $250 a month not a big price to pay to help make the world a little better."

I don't understand how you can think this is going to "make the world a little better" when the evidence is quite the contrary. If you are really looking to offset your carbon, and reduce the coal foot print, then grid tie your system, use your best conservation, and get ~4 times the green for the buck!

It is sort of like saying I drive a Prius because it get 50 mpg, SOV, but my family of 4 commutes each in their own Prius same route same time. True the Prius is pretty efficient, but put 4 people in a Camery , going the same place, even at 30 mpg is going to be net/net way more efficient.

Tony

I'll shut up on this subject now!

Cariboocoot · August 2010

Re: Building a new off grid house in wyoming need help!

You should really consider a grid-tie PV system (if it is allowed in your area). It will ensure that you have all the power you need when you need it (you can still conserve to your heart's content) and any extra you produce will help off-set the dirty coal electric production.

None of us want to see you spend too much money for a system that won't actually meet your needs. There is legitimate concern here that you may be falling into a familiar solar power trap: underestimating loads and overestimating production. Remember: PV's only produce when the sun shines. Bad weather = no charging. It can get dicey.

If you have any tips on how to get kids to stop wasting so much power everyone wants to know!

Photowhit · August 2010

Re: Building a new off grid house in wyoming need help!

myhouse07 wrote: »

AntronX- batterys are green and ele. car use batterys too! Here in wyoming we make 25% of the US power with coal power plants and we mine the other 65% of the coal for the rest of the US power plant. The train tracks down the street from my house move over 50 billion tons of coal a year. So dont tell me whats green or not! What goes up must come down!

For the record I live off grid and have for 9 years or so. Why, originallly to support the industry, now as it's cost effect as the Electric Coop here charges $25 a month for electric and I'm a very small user of electric.

As to that coal your trying to save from being burned, If you run the numbers for an off grid system, you can NOT show that you will produce more electric than it takes to produce the system, Array and batteries and balance of system.

You can backfeed the grid and reduce the demand for coal during some peak hours, and repay the energy used to produce the panels and balance of a grid connect system in 3-5 years or so.

One of the things most who are starting out do not understand, is that an off grid system is only 50% effiecient, when it's charging batteries after the batteries are charged any energy that is produced is just wasted. with a backup genny you might get to a total of 33% effieceientcy (not counting the fuel your using in a genny, also less effiecient than grid...) For people less willing to run a Generator 25% total system eff can be expected (more capacity Array and batteries to make it through cloudy/short days.)

Please don't believe me, do your own research, I think you will find I'm pretty close. Lots of 'math' people here, I suspect others will tell you the same thing.

myhouse07 · August 2010

Re: Building a new off grid house in wyoming need help!

The grid is the problem. My long term plan is to build a off grid sudavison with a mini grid sharing solar, wind and hydro power.

I know it sould crazy to most on here but getting off the coal powerd grid is a good thing.

The first off grid house's do cost a lot and are not a 100% eff. but in time they will be if we keep working on it.

If in 1993 the EV 1 that GM made was not killed by the oil comp. and GW we may all be driving EV car's now. But ppl like some on here only see the small picture. Not the big one!

If we just hook up to the grid and sell or give back power to the oil comp. and power comp. we fix nothing!

If somthing is broke you rebuild it, you dont add to it! It's time to set a new president!

I build home's that ouly use 35,000btu's to heat. I can heat a 4,000 sqt home for less then a 100 bucks on LP gas. with it 40- blow 0 and heat all the DHW too!

Look all I want is some help with my set-up seems like I am on the right track. lithium pio batteries will be out soon that will last 5 to 10 years and bring eff. up to 90%.

SolarLurker · August 2010

Re: Building a new off grid house in wyoming need help!

If building new consider upgrading the insulation, you only get one good chance to do it right. Go with a closed cell spray in foam, and one inch of foam boad insulation on the exterior. Even better would SIP, ballon framing, or ICF construction.

use roof sheathing with a radient barrior and consider cool roofing.

If I were building a new house to be off grid, I would incoporate rainwater harvesting and greywater recycling to reduce well pump run times.

myhouse07 · August 2010

Re: Building a new off grid house in wyoming need help!

Solarlurker,
Your right on the money I am using close cell spry foam in a 2"x6" wall with 1" foam on the out side. 1200 gal. rain cic.

Photowhit · August 2010

Re: Building a new off grid house in wyoming need help!

myhouse07 wrote: »

The grid is the problem....

...Look all I want is some help with my set-up seems like I am on the right track. lithium pio batteries will be out soon that will last 5 to 10 years and bring eff. up to 90%.

First I don't agree with your premiss, the grid serves people well and allows larger generators that are more effiecent.

What will it bring up to 90%?

The ineffeicentcies in off grid are many (I tried to point this out in my last post)

The charge controller steals some, 5-30%

The inverter steals 10-15%

Having to over size your system for cloudy days creates waste of 30-60+%

Lots of things other than batteries, rob effiecentcies in an off grid home.

I love that your building tight effeicent homes, tough I wish they were more modestly sized.

If your doing this to support the industry, or to get rich thats GREAT!!!

I'm just worried you think your reducing your use of the grid, need for coal, or think your reducing your enviromental foot print if you do, I would hope you'd do more research

halfcrazy · August 2010

Re: Building a new off grid house in wyoming need help!

I am off grid and use about the same as you plan to. My daily usage runs between 5-8kwh I have 3kw of PV and a 800 watt wind turbine. I use 16 Trojan L16's. But given your lack of living off grid I would be tempted to try the sam's club batteries I would do 3 strings of 8 and conserve as much as you can. Get a feel for it and in 2-4 years you can upgrade to a better battery bank.

I do agree it is nice to be off grid and use 1kwh a day or less but I can not do that I have radiant heat with pumps and 2 chest freezers as well as a large refrigerator and i despise propane fridges I prefer to add more pv and run a standard fridge.

For me the gird was 250 ft away I just did not want it. I enjoy being my own power company and after 7 years I would do it again.

myhouse07 · August 2010

Re: Building a new off grid house in wyoming need help!

halfcrazy,
Wow so it can be done! ppl on here act like I am crazy and p-ing money down the toilet.

Halfcrazy thank you for your help. The first time the grid gose down for a few days they will all wish they had off grid homes!

Think I will use 24 sam battery for my first ones thanks!

icarus · August 2010

Re: Building a new off grid house in wyoming need help!

I think we have beat this dead horse, (me included) Myhouse has made is choice, and we have opined on the wisdom of that. Now I think it time to move on and help as best we can.

Tony

Photowhit · August 2010

Re: Building a new off grid house in wyoming need help!

Other than "Golf Cart" batteries the only other competing battery for cost effectiveness would be a traction battery. A Forklift battery in the same range might cost $6500 - 8000 (haven't looked for a while) but might well last 15 years. Note they do need a slightly different mainanance routine, but would have a third fewer cells to check.

I don't think anyone here said it can't be done, just that it's NOT green, your not saving the world...

Cariboocoot · August 2010

Re: Building a new off grid house in wyoming need help!

If a man wants to spend his money making a political statement, that's his business.

What I don't get is:
You're spending huge amounts on high-efficiency insulation, heating systems, et cetera. You're evidently not concerned about the $ spent on the project, and yet you're looking at buying the cheapest batteries you can find?

Batteries are the heart of an off-grid system. It doesn't pay to have under capacity or incorrect charging or anything else "out of spec".

I'd go with the Trojan 2V cells and up the panels/controllers to get maximum capacity.
But first I'd quadruple check the power requirements for things like the heat pump. Anything that's any type of pump or compressor; they use lots of power and can use unexpectedly high amounts because their demand varies with how much work they're doing.

Storage, btw, is the problem for both off-grid systems and the grid itself. My brother-in-law is in the business, and spends much time talking about the endless headaches of trying to manage production against demand. It is not as simple as you might think.

icarus · August 2010

Re: Building a new off grid house in wyoming need help!

myhouse07 wrote: »

halfcrazy,
Wow so it can be done! ppl on here act like I am crazy and pissing money down the toilet.

Halfcrazy thank you for your help. The first time the grid gose down for a few days they will all wish they had off grid homes!

Think I will use 24 sam battery for my first ones thanks!

The first time the grid goes down, most people wish the had a generator! 1/100 the cost, and ten times the capacity!

Sorry, couldn't resist.

And you are right, there is no reason it can't be done, it is only a matter of the cost of doing so.

Building a new off grid house in wyoming need help!

Comments

Categories