Coming up on the off-grid crossroad

[TheUnknownCat]

Hi folks, thanks for your time. I'll try to keep it brief, but I need your help -and I know that this is where the gurus live.

I became interested in alternative energy a few years back, and was lucky enough to find myself here, to learn that I had a lot to learn. My main motivation in learning about this subject was in the interest of self sufficiency as a retirement plan, even though I live inside of an Oklahoma city, with grid power readily available. I learned from you good folks that a windmill was about the last thing that I needed (I did buy the book though, and intend to build at some future point) -that if I was going off-grid, that what I needed to learn was how to live differently, which I have done, in earnest.

Over the last three or four years since I first joined this site, my wife and I have changed our lives drastically, learning how not to use electricity, and overall changing our lives for the better on many levels through these endeavors. Based on our available options, we chose to emulate the model of an early 20th Century Oklahoma homestead to achieve our goal of self sufficiency, (all of the old gear is still available as "antiques") and we began learning small scale farming and poultry production on our half acre lot, and are presently remodeling our fairly new and very efficient 270 square foot house to better suit our changed needs. What that basically means is that the all electric kitchen is being torn out, and the electric range is being replaced with a wood-fired cook stove, (to be used in the Winter months for cooking and heat. Summer cooking will be done outdoors on a similar wood-fired range, in an altogether separate kitchen.) The electric water heater that supplies hot water to the kitchen sink and bathroom shower will be replaced by two separate propane fueled instant hot water devices, and the refrigerator will be replaced by the reportedly super efficient (new, 9cf) chest freezer/refrigerator conversion. We also will need to operate a (new) 9cf chest freezer, and, because of the particularly windowless construction of the house, up to a few hundred watts of (I believe that I want inverted 110v) lighting. A small, 1/10hp swamp cooler will be providing Summer cooling, since I also just permanently removed our electric heat and air unit, (I've been heating with wood the last few years, we have a good supply of it.) There is the computer, of course. The laundry facility is a completely separate structure, and will be run by generator on "laundry day," and any small appliance loads could be picked up by generator, as well.

Mechanically, I'm very good, and that is what has gotten me this far, (and frankly, I'm a little bit brain-tired after pulling all of this off,) and while I am fairly experienced with working with electricity, I'm trying to dodge a bullet and not have to study to become an electrical systems designer, and would hope to lean on your experience -so I can just go straight to becoming an electrical maintenance engineer.

I know that hard numbers are the only way, and I will provide them ASAP, as measured from a "Kill-A-Watt," but a good guess is all I have right now, and I know that the guesses here are better than mine -but I need to begin planning, in at least a vague sense. This is an active project, with a hopeful off-grid deadline of "late Summer," and I'm looking for advice on an overall off-grid solar system. There are too many choices out there -and most of them can't possibly be right for me. Based on my own reading, I'm leaning toward an Outback inverter/charger as the heart of the system, a suitable solar array, and an appropriate battery bank. I already have an electric start 3500 watt generator that I'd like to tie into the system. I tend to like the idea of initially buying more inverter than I need, that I could possibly increase in generation and storage later. I'm currently on city water -but the ability to pump a well may be nice later.

Tonight's best guess;

9cf (new) Chest Freezer/ Fridge conversion, .2kwh per day, (so I've read)
9cf chest freezer 1kwh per day +/-
Lighting 1kwh per day (guesstimate)
Evaporative cooler (Summer only, should be around) 1kwh per day
Desktop Computer (?)

What am I looking at here, guys? Am I in the ballpark?

Try to be nice -I've refrained from asking stupid questions for four years, just so I could save up to ask this one.

[DamonHD]

Hi,

A handful of points while waiting for my work machine to reboot, and a note that it all depends somewhat on your motivation...

1) For me, replacing electricity kWh with propane kWh is not necessarily an improvement if the same amount of CO2 being emitted somewhere.

2) A few hundred Watts of lighting is an awful lot.  I doubt that all the lights on at once in our 800sqft-ish house add up to that.  For example I've just put a 10W LED (mains, so 240V here) lamp in our bathroom that is roughly equivalent to a 60W incandescent, and I had complaints that it was 'too bright'.  Our living room has ~35W of CFL, my work light at my desk is 7W of LED, etc, etc.  Think efficient lighting and a few *tens* of Watts is all you should ever need on at once indoors IMHO.  I don't believe that our lighting can add up to even 0.5kWh/day mid-winter.

3) Given a choice, and if driven by energy efficiency, a laptop is *designed* to sip power to extend battery life.  A desktop less so.  A good modern laptop (with LED backlit display) can idle on 10W or less and sleep on 0.1W.  A desktop machine will be unlikely to be as good as that.  And remember to have the thing autosleep, dim the screen, etc, when not used for the shortest period that won't drive you mad.

Rgds

Damon

[TheUnknownCat]

I know you guys don't work for free, so if it works for you, I'll be paying with pictures of what we're doing, now that we're getting closer to having something to show.

Here's the wood cookstove we're putting inside of the house in the next few weeks:

[TheUnknownCat]

Thanks for the quick response, Damon. I know that is a big lighting number -but we have minimal natural lighting inside, and while it is still negotiable in the design, I want to leave it a wide margin, this place is small and dark, and sometimes it needs to be lit up bright. This number also includes a nice, big, 60w CFL yard light on photocell -which isn't negotiable -it keeps the bad guys at bay, I live in a city. The desktop computer is necessary for work -which pays for all this other junk -so it has to stay. Believe me, I've cut the fat.

Edit:

Regarding propane, it's a good choice for my goals, because it will allow me flexibility in how I pay for heating my water. (I intend to add solar heated water later also.) As far as the carbon aspect, I believe it works because the propane will only burn as needed, whereas the 40 gallon tank is the biggest offender in my current use -idling constantly on electricity, whether being used or not.

[Volvo farmer]

Self sufficiency as a retirement plan.... Hmmm, Those two terms strike me as being possibly in conflict with each other, as people are often trying to save as much money as possible when they retire.

If you have been researching this for a couple of years, you know that it is almost always more expensive to make your electricity with an off grid solar system than it is to buy it from the grid. If you are really planning on paring down your electrical needs  to the bare minimum and are willing to use a chest freezer as a refrigerator to save electricity, I would imagine that your electric bill would be somewhat less than $35/month, or $420/year. By the time you buy a nice outback inverter, some solar panels, a charge controller, batteries, and all the stuff to hook it up, you're likely to be out 4 grand. So there's 10 years of electric bills. Sometime within that first ten years, you will certainly need to buy another set of batteries, because the first ones will be worn out.  I haven't even touched on how many generators you will wear out or how much fuel you would have to buy for them in that period.

Now if you want to be self sufficient for the sake of being self sufficient, and don't care if it costs more, or if you want to be like Damon and stop ruining the earth with CO2, and don't care if it costs more, then I would encourage you to forge ahead, but don't do it to save money, because you won't.

[DamonHD]

Just for the record I do all my work at home on laptops; mainly my MacBook but also a Windows 7 machine is used a little.

And my main internet server, also on my desk at home, consumes 4W and runs off grid.

Not a desktop machine in sight, and like you, computing pays for everything else.

So it can be done.

I also thought that I liked everything lit up BRIGHT but now less so.

And a 60W CFL?  Goodness, that must blind passers-by once it has warmed up!  B^>  I live in the wilds of London on the edge of a "sink estate" but thankfully don't seem to need such heavy-duty security lighting.  BTW, there's some good LED-based security lighting around now: instant on and more lumens for your Watt than CFL I believe.

BTW, my battery-powered nightlight, that my daughter uses to navigate to the loo at night, uses milliwatts and runs for months on a set of (solar-charged, of course) AA cells.  Lights up the hallway and some of our bedroom!

Rgds

Damon

[TheUnknownCat]

"Self-sufficiency as a retirement plan" works like this, for me; I need to have control and flexibility in my expenditures. I'll be earning my money in various small ways -because I already don't require much "cash" in my day to day life, and I don't want to find myself facing the pressures of even a minimal electric bill. I want to be able to plan ahead for my needs, without anyone threatening to take anything away from me if I do not meet their time frame. The entire place is a working machine, so investment return in the sense of dollars isn't the point. I'm also aware of battery bank life, so while I still have good income -that will be planned for in advance.

While I find "sustainability" admirable, I'm more interested in "survivability." This place, frankly, is an inner city fort in an area that my grandfather and his brothers helped build during the 1930s and '40s and it is where my mother was raised. I've been here for twenty years -I'm not leaving. As I grow older, (I'm 48,) I need to have systems in place to make up for my own shortcomings -like a 60w yard light, which is on a pole near the front of my property, facing the rear of my property, and lighting up the whole place, with any "light pollution" glaring into the vacant sixty acre woods that abut the rear of my property -which has a pretty serious security problem potential. This isn't exactly a crime-ridden area, but it is an old neighborhood, and things do happen here -and making sure they don't happen in my yard is my responsibility.

My lifestyle is probably somewhat other than "typical," but it's mine, I chose it, I love it -and as any installation -it will have a few odd needs that must be met, needs like a serious yard light, and "I aint even gonna try to wrestle my wife's desktop work computer from her."

That said, I'm still in a bit of a quandary about lighting inside of the little house, although I'm narrowing it down. It is important enough that I am willing to pay for the system to operate it, but I still don't know entirely what "it" is, so I think leaving it a wide margin at this stage of design is important -any excess power available could surely be used somewhere else. My house interior dimension is 12.5' X 22.5' with only two (approximately 2'X 5') windows in the North facing wall -there is minimal natural lighting. Cutting windows into the South wall isn't an option -and would create a cooling problem in Summer anyway, which is a very serious consideration. I've played with converting my current T12 magnetic ballast fixtures to T8 electronic ballast fixtures, and can achieve what I need available with a total of two fixtures at 96w each. These lights only need to be available -they aren't going to be the "always on" light to keep me from hurting myself in the dark. I intend to find some small, efficient lighting for consistent use.

I've cut down my use to a pretty respectable level, a level that will meet my needs. I am ready to move forward. What you guys are doing is freakin' great -which is why I am here -I need your help with what I am trying to accomplish, and need some help designing a solid, dependable, expandable, (wind, potentially,) system that will meet those needs.

I haven't cluttered up the site learning the basics but I'll gladly post lots of install pics and info, to help the next guy.

[Volvo farmer]

Sounds like you might need about 4KWhr/day?

That's about what we use, well, maybe our usage is closer to 5kwhr/day.  You need to look up the solar insolation (sun hours) for your location. I have 5 at my location. If yours is less, you will need more panels.

We get by with 8x 170 watt panels, 8x L16 sized batteries, MPPT charge controller, and an Outback 3500 watt inverter.

Just the stuff I listed is about $7500 with today's solar panel prices.  I'd budget at least another two grand for AC and DC electrical boxes, breakers, solar panel interconnect boxes, racks and wiring.

You really need to get one of those kill-a-watt things and go around and measure how much electricity you use, or if you are currently grid tied, you could just get the number off the electric bill. 

I think you only need one on demand water heater. We have 4 people in the house, and everyone knows that you can only run one hot faucet at a time and have adjusted.

You might look into stand alone solar powered motion activated yard lights. We got one of these recently and it works good enough for the wife to get her car keys out of the purse from fifteen feet away.. No way will it run all night long though.
http://www.sportsmansguide.com/net/cb/sunforce-60-led-solar-light.aspx?a=910217

Cheers!

[TheUnknownCat]

Thanks for replying, Volvo Farmer, it seems that you are sized about where I need to be.

Since I have a general size range now, I'd appreciate some fed back on the 3.5kW FLEXpower ONE System as a starting point.

http://www.wholesalesolar.com/inverter-system/outback-power-flexPower-solar-power-center-fp1-1.html

Is this a good starting point to design this system from? Aside from this package, what will I be looking at aside from an array and rack to hold it, and battery bank and cables?

I appreciate all help, and any other product suggestions.

[Volvo farmer]

Woah, nice shopping there. That's a pretty good price on that thing! I think that would be an excellent start to an off grid system. I personally am enamored of Midnite Solar products, but Outback makes good stuff too.  Back when I built my system, there were no modular plug-n-play boxes like that.  I think you have it about covered with the stuff you listed, minus things like array combiner boxes and breakers, which are pretty cheap.

I would recommend finding a dealer who you trust before buying all this stuff, and listening to their advice. The guy I bought my stuff from listened to me and got me most everything I needed in one order. He helped me avoid common mistakes and pitfalls, and his pricing was excellent.

Keep us in the loop as you build this thing. Sounds like you are having fun!

[TheUnknownCat]

Thanks for the good advice. I'll be sure to keep yall posted as this thing happens. I'm presently hung up plastering the ceiling. Good time!

I also found a local trailer manufacture that was selling 12v interior lighting at about 10% of retail, (they make utility trailers, not RV's -and he got a lot of RV interior fixtures in a purchase where he had to take them to get the things he wanted,) so I bought a pile of 10w G4 bulb lighting at a great price. I'm thinking of running a 12v circuit for casual lighting, and have an inverted circuit for when we need to see what we're doing.

I'll get to the bottom of this yet, I appreciate all of the input.

[hydrosun]

With those 12v fixtures you can save even more power by switching the halogen bulbs for leds. i just put some 3 watt leds from ebay to replace 10 watt halogen bulbs in all my reading lights. The leds are a nice crisp white, which I like for task lighting. the overhead lights are led barts. I got tired of replacing fluorescent lights didn't seem to last too long.
Chris

[thirteen]

Could you put in a skylight somewhere to get some naturel light in a darkened corner or hall.

[WindriderNM]

You could us a water tank on a tower and fill it by pumping water while the generator is running on laundry day. We have a 300 gal tank that we filled this way until I made a low volume low power solar pump. It lasts about a week. In addition to saving elect. we have also learned to save water. We use our gray water to water the plants as well as for the toilet. 

[peter altas]

60W CFL flood light?

I use a 400W HPS flood light on occasion. Granted it doesn't run all night for security, but I do use a couple of 150W MH floods fairly often to light up areas on my property, and I have a stand alone off-grid system.