Off Grid Home

[southernsis]

Does anyone have some advice for an off-grid home? Any web sites worth investigating? We are going to build a home in an area that has no power for at least 15 miles. We have a stove/range that runs on propane, will burn wood for heat. We need to be able to generate enough energy to run my husbands tv, lights and my computer. We don't know yet about drilling a well and will put in a septic system.  Any help for the person who is uneducated in this area? Thank you

[NM_Shooter]

Oh, this should be fun!

What part of the country are you building in? How much sun do you get?

Will this be a full time home?

Are you going to be doing laundry here?  Do you like to line dry?   

Here's what I would do for a home...Solar is very expensive.  If this were a full time home, and you are looking to save some $$$, I would consider a split system.  Maybe 400W of panels feeding a 4 or 6 battery array (6V Golf cart).  Get a good inverter, and a good charge controller to optimize the amount of power you get from the sun.

Put in solar hot air boxes to heat the house during the day.  They sit out on your roof, blow hot air, and are incredible.  Save your wood stove for at night or extra cold days.   

Supplement this with a 6kW generator and transfer switch at your panel to power any large appliances (like a washing machine), larger power tools, or for emergency power.   Use compact flourescent bulbs everywhere.  Small TV.  Keep in mind that a lot of modern electrics use power even when turned off.  Unplug everything when not in use. 

Propane fridge, and probably seperate propane freezer.  Consider using an elevated cistern for your well water.  Use the pump only to fill the cistern, then use gravity feed for the house.  You'll need to use the well pump once temperatures drop (maybe... depends on where you live).

I'd split my wastewater too.  Getting out to pump that septic is probably going to cost extra.  Put gray water straight into a designated gray leach field, or save it in a tank for gardening.  Only put black into the septic. 

Looking forward to other posts!

-f-

[MountainDon]

We are doing much the same thing. Our mountain property is about $55K away from the local power grid.

Some folks take the route of keeping everything running 12 VDC. That does have the advantage of eliminating power losses that happen when you invert DC (battery) power to AC (power grid) power. But there are limitations. Some are, heavier wiring required for the low voltage DC system, special appliances that will run on DC power. So the below are my thoughts on the matter.

The first thing you need to do is do a real honest assessment of how much electrical power you will be using. Now and future. The number of lights (CFL's are the only practical type, IMO) and how many hours a day use. As Frank pointed out you may have some items that aren't used enough to warrant the expenditure necessary to run them off solar electricity. Generators are required in any case for periods of prolonged no sun, and equalizing the batteries monthly. Generators are also noisy smelly beasts and they burn expensive fossil fuel, so I plan to run it as little as possible.

Only LCD TV's make sense to me because of the low power draw. Probably only available in 120 VAC, though I haven't looked. We use one with a built in DVD player that uses less than 50 watts (17"). Are you going to want/need satellite feed for programming?

Frank mentioned things that use power even when not in use. TV's  or anything with remote controls fall into that category. Plugging things like that into a switched power strip can eliminate those phantom loads.

After the power needs, you'll need to determine how much battery storage capacity you'll need, and how many PV panels to supply the recharging power.

You mentioned a computer. Laptop or desktop? Desktops usually use more power. Add it up. Internet access by satellite?

Occasional use of a vacuum cleaner? Coffee maker? Microwave? You can use the appliance nameplate to find the rated power use. You can also buy a tool called a Kill-A-Watt to measure your actual use. They're available from many sources, amazon.com is one.

This web page at Affordable Solar has off grid info you'll find useful.
http://www.affordable-solar.com/solar.off.grid.remote.htm

There's an off grid power use calculator link on that page. The direct link is
http://www.affordable-solar.com/index.php?file=c-off_grid
You can use that and email the results off to one of their people to have them assist in forming a system.

The forum members can help to the best of our abilities as well. Feel free to ask more.

Another couple different calculators that get into batteries and panel needs as well are:
http://www.wagonmaker.com/script_calculator.html
http://store.altenergystore.com/calculators/off_grid_calculator/

I also have an Excel spreadsheet that can be used for sizing systems. No guarantees, but it seems to be working okay. I could email it to anyone interested.

[BiggKidd]

Hi

I am in the process of setting up an off grid system myself. You can sped lots of $$$ here. But there are ways to cut costs. I got 16 12V UPS batteries from a buisness system free. They are about 3 years old with a ten year life. Another thing is inverter types for sine wave (clean power) big bucks about $1 a watt. I am using a modified sine wave inverter 5000 W cost $419. So far it runs anything I have put to it fine. For charging I am using a home built charger. I made it out of an old alternator and 5.5 hp briggs&stratton engine. We used it for 9 days of charging while on vacation and only burned 5 gal. of gas. My 3500W genrac burns about 1 gal an hour. When I was using the battery charger / genrac it took about 8 hours to charge the battery bank. With the charger I built it only takes about 4 hours. I have also bought some solar panels from harbor freight they seem to work well. Not as high quality as most but they work fine, don't know how long they will last though.

Here are a few pics of my system. Click on the picture to see full size.


















I am sure lots of people will see problems with my little system but it works. We run a dorm fridge & lights and radio all the time when we are there. Also I run power tools for projects / building as needed. We also use 12V water pumps and a few other 12V lights and fans.

Modified to add we also run a microwave a few times a day. Wife caught that one.

Hope this helps.
Larry

[southernsis]

We will have lots of sun. We are building in Southern Oregon. We are still in the planing stage, but when we build we want to design for the use of solar and other things so we don't have a problem later. I thank everyone for the advise. Now I have an idea where to start. My husband is not going to give up his plasma tv, so have to figure out how to run that.
Thanks again

[Redoverfarm]

BiggKidd where is your battery bank in relations to your living space.  I was always told that there is a good amount of acidic gas given off while charging.  I was just wondering.  I will utilize a battery bank/inverter in my cabin.  I will install a rack system for storage and probably partition off that area and install a vent to the outside to eliminate the threat. 

[MountainDon]

Those batteries would be gel cells, MTL. Totally sealed. Good and bad.

(UPS = uninterruptible power supply, not the parcel delivery guys) 

Most folks will use lead-acid wet cells and those definitely require good venting.

[BiggKidd]

Red,

They are in a storage shed around 30 ft. from our camper. Yes the gases can be deadly. BIG BOOM.

Don,

The are VRFL valve relief flooded lead. I'm new to battery terms but my understanding from their web site is that they use glass mat technoligy but its still a lead acid battery.

These were given to me so thats about all I know.  Heres a link to the batteries I have.

http://www.cdstandbypower.com/product/battery/vrla/pdf/12_475.pdf
They have been discontinued.

The longer I fool with this system the less I Know.

Larry

[MountainDon]

AH!. They use AGM technology. (Absorbent Glass Mat). They are better than Gel Cell. They can be mounted upside down or sideways, like Gel cells. Thay can be charged at higher rates than Gel cells, actually they take an overcharge better than lead-acide open cell batteries. They don't outgas when used as designed.

I use AGM's in my Jeep. (see Optima Batteries). I've been told that even if the case is cracked, the electrolyte does not leak. Optima's have the lead and glass mats wound in a spiral. Sic spiral cells to a 12 V battery. They withstand off road bumps and vibrations as there's nothing inside to shake loose or out of place.

and the price was right.  AGM's are more expensive than regular flooded open cell lead-acid batteries.

[BiggKidd]

 Don,

  When I got these batteries they sat in my garage for a month or so on a pallet. But when I checked each of them they had 13.1V. Thats the highest voltage I have seen on a battery that wasn't just on a charger. Thats what they go up to each time is that normal? Don't you just love us newbie's. Don't realy have a clew what we are doing!

Larry

[MountainDon]

   Even a conventional 12 V open cell lead-acid battery will show about 12.7 to 12.75 VDC at rest and fully charged. That may be just those batteries, or the meter. How does it read a standard car battery? Digital meter? (better than analog)

You should wait at least two hours after charging before taking a reading in order to get a valid figure. There should also be very little id any discharging going on.

This is one of the drawbacks of sealed battery technology. You can't take a specific gravity eading of the electrolyte. Not a big deal compared to the advantages.

[jan nikolajsen]

hi,

please see our place at

http://coyotecottage.com/

you should have a lot of fun doing all that stuff.
we have been off the grid for 5 years or so, using a VERY modest system, yet living a relatively normal existence, with a kid in school and some part-time work. in other words, we're not hermits on some far off mountain side.

it is not difficult to build an airtight box vented to the outside for the batteries. that way you can keep them inside the heated envelope and avoid numerous issues with cold temps. our battery bank is still reading good after 5 yrs.

we have 400 watt of panels, 4 trojan 105 batteries, a cheap generator, even cheaper inverter and are doing fine. i run a 700 sq ft wood shop off that system, with negligible generator use. not building cabinets, though, but wooden boats.

the cabin has lights (all LED), small electric fridge, 2 laptops, water circulation pumps, some simple kitchen appliances. only in the dead of winter do we need to be careful, but this still amounts to more than 3 months of electric deprivation. all in all, it is a better life than any alternatives we have experienced, save cruising in a small boat.

good luck, jan

[Redoverfarm]

My hats off to you.  Congratulations on your life style choice. But I was wondering if your boat building buisness is the only source of your income?

[jan nikolajsen]

half of it, roughly. living rurally income comes piecemeal!!

jan

[MountainDon]

How one becomes electrically self reliant depends on what is deemed as necessary vs. want is desired/wanted.

The introduction of a plasma TV into the equation would necessitate a somewhat larger system than Jan's, IMO.

The TV would likely use more power during say a single ball game than Jan and his family use in a month. Well, maybe that's an exaggeration. 

[glenn kangiser]

Looks like 230 to 500 watts by itself, so could use more than the total output of a small solar power system.

Unplug the Freezer -- Dad wants to watch the game.

[glenn kangiser]

That said - we run two computers - printer - dsl-wireless-  stereo - 2 freezers and a refrigerator- some shop tools and occasional welder and small rock crusher - pump about 500 gallons of water per day on 2000 watts panels and a 1000 watt wind generator that puts out about 1/4 th of our power estimated.

[MountainDon]

Yep, but few of those will run three hours straight drawing that kind of power. 

My cabin plans call for about 500 watts worth of PV panels in very sunny NM. Even the best exposure in south Oregon won't come close to that. I plan on worst case of 3 days cloudy with batteries sufficient for any imaginable likely loads. (700 amp hours +- 100-120 @ 24 VDC). I've been running the numbers for a year or more and there is no way I could replace the LCD TV (50-55 watts) with something like even the smallest plasma job. And I'm only planning on a few hours a week of something off a DVD recorded at home base. No sat dish setup sucking more power.

That said, you can run a normal home off solar PV power. It just costs more than what Jan or BiggKidd have in their systems. But it may still be a lot less than 15 miles of power company hookup.

[glenn kangiser]

Yup -- I'm about as normal as they get.

[Bishopknight]

Being very frugal/cheap myself, I tried to find the cheapest way to get hooked up...

I estimated I will use 1600 watts per day ( 48 kilowatts per month) in central Maine so I will need 600-+ watts of power.

I found 4 excellent condition AGM batteries on Craigslist for $30 each.

I also found a pure sine wave inverter on Craigslist for $200, normally $600.

I have a Tristar TS45 charge controller which will handle up to 45 amps and I bought 4 guage battery wires from Autozone for connecting the bank.

I can hook up to 6 kyocera Kc130 watt panels to it no problem and it will give me enough power to run lights, laptop, small tv, tools, microwave.

Hope this helps others find a low cost solution that fits their needs...

[NM_Shooter]

Being very frugal/cheap myself, I tried to find the cheapest way to get hooked up...

I estimated I will use 1600 watts per day ( 48 kilowatts per month) in central Maine so I will need 600-+ watts of power.

Thanks...

Do you mean 1600 Watthours per day?  If so, I am impressed!  That is very frugal! 

[glenn kangiser]

I'd say -- much more will power than me.

I use 10000 to 12000 per day.  I could save more but would rather build to cover all I may want as if living on grid with propane used for major items such as drier, hot water, second fridge, cooking.  A couple more panels could eliminate the propane fridge - or maybe just putting up the racks for the panels. 

[Bishopknight]

Yes, this is the estimate atleast

My plans are for a cabin-like setup aimed at conservation. I will admit I've only ran 1 of my 130 watt panels at my old house in texas with 1 of those batteries ( on the Charge controller/Inverter) and it powered my tv, ps2 and cable box for hours each night. But maine is much different than texas!

My estimates on power only account for a laptop, 4 florescent bulbs, small tv, microwave, power tools, dvd player, coffee maker, toaster. I'm figuring a propane fridge ( or larder room ), wood/cooking/rocket stove and possibly a lehmans sink washer for clothes.

I think in a post peak-oil world, my setup will be more than comfortable

[Okie_Bob]

I'm envious of all you off-griders...very envious!!! And no, Glenn has never been called normal...at least since I've been around.
FYI, beginning next Feb 18th, all tv stations must stop broadcasting analog signals and convert to digital permanently and completely. What this means to you is that your old analog tvs will not work any longer unless you add a 'conversion' box which converts the new digital tv signals back to analog for your old tv. This converter won't require much power but, you are all being so cautious about your power usage, I wanted to let you know about this.
The alternative is to buy a new digital tv. I just did a very quick look to get an idea how much power to expect to use and found a 42" LG LCD (flat panel, high definition) that uses 210Watts. Could not find the stand by usage but, it would be very small amount.
Just something to be aware of while calculating your power needs in the future.
Okie Bob

[MountainDon]

When calculating what your loads will be it's always best to allow yourself a cushion of some sort after you've been totally honest/generous in your use assessment. I also draw the line differently for a location that's a full time home and a location that receives occasional use.

The phantom loads can add up. In some instances it may be more convenient to install more switched receptacles so things like the TV, sat dish, microwave, etc. can easily be switched totally off between uses.