Advice for Off-Grid desert cabin

Hairfarm

Greetings,

I just purchased a cabin to rebuild recently. I have plans to add a plastic water tank and to restore it to usable condition. My goal is too have it powered using a solar system. I'm not familiar with solar and how it really works, but basically we'll be using the following electrical items in the cabin:

1) 1/2 or 1 hp electric water pump from outdoor tank - roughly 3 gal. per minute @ 100watts
2) small refrigerator
3) computer
4) various indoor lights
5) stereo and tv
6) electric stove
7) water heater
8 ) coffee pot and coffee bean grinder
9) microwave oven

We won't be running this all at once, but we will use everything on the list at one time or another.

What would our budget likely be to set up a system like this. Since it's off the grid, we would need a battery backup system and a generator that would feed the batteries if no sun for few days.

Here is a picture of the cabin:
http://www.sitnsail.com/hairfarm/Otherstuff/Cabin/0626291510000.jpg

Any suggestions for the best system and price?

thanks,

Hairfarm

BB.

Re: Advice for Off-Grid desert cabin

To puncture your bubble a little bit... Solar RE energy is expensive!!!

So, your "electric appliances" used for heating, cooking, etc. are probably better off running from regular fuels (gas, propane, diesel, etc.) and/or or use various solar thermal collectors (hot water, solar hot air, solar ovens, etc.). Solar Thermal can be quite cost effective for "low grade" heating (hot water, heating, perhaps a solar oven on sunny days and long cooking items).

Just to give you an idea... Your utility power is ~$0.10-$0.20 per kWhr.

Your Solar RE system (parts, battery replacement, perhaps some professional installation) will run you $1.00 to $2.00 per kWhr--or 10x as much as your home power costs.

Typically, a "cost effective" system is for powering small, highly efficient loads. Not to say that you could not build a system large enough to power an electric stove--but it will cost you a huge amount of money to do so ($x0,000-$100,000).

In the end, there are two values for generating your own electricity that you need to look at... One is Peak Power (simply, how many watts you need to power at the same time) and, how many Watt*Hours do you need to power in a day. Believe it or not--typically the expensive part is Watt*Hour per day that will drive your system costs.

For example. Lets look at a microwave and a home desktop computer system.

The Microwave--lots of power--perhaps 1,500 Watts peak. But, you only run it a few minutes per day to heat food:

1,500 Watts * 20 minutes per day / 60 min per hour = 500 Watt*Hours

A desktop system--you are looking at ~250 Watts for tower+monitor+Laser Printer... And you use it 12 hours per day (work and audio/visual entertainment.

250 watts * 12 hours per day = 3,000 Watt*Hours per day

So, the computer system is 6x more power than the microwave...

A recommendation would be use a low-power Laptop at ~25 watts (turn the printer on only when you need it, etc.)--and all of a sudden, it is not 3,000 W*H but 1/10 that at 300 W*H per day.

In the end, people get away with living in a cabin full time on less than 1,000 Watt*Hours per day (30 kWhrs per month). And, I would recommend that for your monthly usage you aim at less than 100 kWhrs per month (100,000 Watt*Hours per month). Most homes in the US are around 600-1,000+ kWhrs per month--so that is some serious energy reduction for most people.

To start, review your current utility bills and start estimating energy use. For smaller devices a Kill-A-Watt meter (120 VAC 15 amps max) is a great tool for this job (less than $30.00)

Kill-A-Watt AC Power Monitor Meter
P4400 Cumulative Killowatt-Hour Monitor

Lets price a system that generates 100kWhrs per month (3kWhrs or 3,000 Watt*Hours) per day, for at least 9 months out of the year (use genset to make up winter production). And assume you are in the high desert of southern California. Using the PV Watts Website (use 1kW base solar panel wattage, 0.52 overall system efficiency, Daggot CA):

[FONT=Fixedsys]
Results

Month
Solar Radiation (kWh/m2/day)
AC Energy (kWh)
Energy Value ($0.125 per kWhr)

1      5.59          85        10.62   
2      6.03          80        10.00   
3      7.10          105        13.12   
4      7.74          109        13.62   
5      7.42          104        13.00   
6      7.42          98        12.25   
7      7.33          97        12.12   
8      7.40          99        12.38   
9      7.34          98        12.25   
10      6.76          97        12.12   
11      5.78          83        10.38   
12      5.20          80        10.00 
======================================= 
Year      6.76 ave sun hr    1135kWh $141.88 per year[/FONT]

Tossing the lowest three months of generation (80, 80, 83), the next is 85 kWhrs per month @ 1kW of solar panels. To convert to 100 kWhrs per month:

100kWhrs per month / 85 kWhrs per month per 1kW) = 1.2 kW (1,200 watts) of solar panels.

Very roughly, a 1.2 kW off-grid solar system will cost around $12,000 to $24,000 (self installed, shopping for best prices vs turnkey install).

We can go into the details to help you better price the system--but until you know your loads--that is sort a waste of time right now.

The above estimate of price is at least close enough for you to compare cost trade offs between appliance selection (propane stove, solar thermal hot water, etc.) and impact on your Solar RE Installation costs. (I am not an installer or connected with any solar retailer/vendors--just educated guesses from helping price systems here for others over the last couple years--some systems will cost less, some may cost more--just enough information to help guide your decision process).

Also, remember, that for an off grid system, you will need to replace the battery bank approximately every 5-10 years (more expensive batteries tend to last longer--and first time off-grid people very often kill their first battery bank in less than 3 years).

Questions?

-Bill

icarus

Re: Advice for Off-Grid desert cabin

Bill's got it dialed as usual.

No electric heating appliances like toasters, coffee makers, irons, stoves etc. Propane for heat, water heat, and if the cabin is only used occasionally propane for fridge.

My guess is that ac might be your biggest energy demand,,, invest in evaporative cooling, or high ef heat pump,, ground water or earth loop,, and PLANT SOME TREES to shade the house and reduce the cooling load.

Just for the record, we heat with wood, use propane for all our other heat sources including coffee maker. We use solar for water pumping, lighting, lap top charging, satellite modem and router (no TV or Sat TV) paddle fans radio etc. and we use ~3-700 watt/hours/day. That is paying particular attention to loads. This is with a 300 watt system.

Good luck. welcome to the forum, and spend a bunch of time getting educated to avoid the "ready, fire, aim" syndrome that too many fall into and end up with Harbour Freight junk.

As we say, all to often here,, (and Bill) suggests, "Do the math" Conservation is your cheapest PV $$. For every $ spent on conservation,, it will save ~$10 in PV costs. Do the math with the loads,, and eliminate all the unneeded ones, using better, more efficient technology. Gas hot water,,, preferably demand,, with solar pre-heat etc. For example,,, amongst so many others,, a 1500 watt coffee maker,, running 15 minutes a day will burn 350 watt hours,,, just about what we use in an ENTIRE day for all uses. (Coleman makes a great stove top "Mr coffee machine that works great on a gas stove for example) Same with a toaster,, 1000 watts for 10 minutes = ~ 100 watt hours,,, where a stove top gas toaster burns almost no gas. Find the phantom loads,, a 15 watt Satellite receiver will burn ~30 24/7 EVEN when it is OFF! 15 watts X 24 hours =360 wh/day,, once again, nearly as much as we use in a day! 5 watt power supply for an electric clock, 120 wh/day. And so on and so on.

Eventually you will find a number you can live with,

Good luck and welcome to the forum,

Tony

BB.

Re: Advice for Off-Grid desert cabin

Tony/Icarus is obviously on the "low side" of living with solar power--so, unlike me who is living On Grid with Grid Tied Solar--Tony and his wife has lived the low impact life style (but still has Internet--priorities! ).

You will find some points where there are credible either/or solutions (propane vs solar electric)... For example, the "Fridge"... You can get propane power, DC powered, or even just use an Energy Star Rated 120 VAC unit (and use the cost savings to buy a bit more AC Inverter, solar panels, and battery bank). And, you can even go with "home brew" and convert a chest freezer into a very low power fridge (1/4 the energy use of a similar Energy Star Fridge).

Research and ask--not everything made for "off grid" use is worth the money (off-grid refrigerators are one common appliance that is not always worth the $$$).

-Bill

icarus

Re: Advice for Off-Grid desert cabin

Please do a search on this forum regarding my opinion of Propane vs electric fridges. (Perhaps it should have it's own thread)

In short,, modern energy star fridges are a great for PV solar, IF the house is going to be used full time. The pay off is quite quick.

LP makes great sense if the house is used occasionally,(weekends, vacation weeks etc) as the PV costs are pretty big for a conventional fridge,, amortized over 365 yr as opposed to say 30 days a year. If I had to do it over again,, I would opt for conventional rather than LP,,, but I'm stuck for a while.

Tony

PS. And Bill is right,, we do live on the bottom edge of the scale in terms of usage, but we don't have to scrimp.

T

Cariboocoot

Re: Advice for Off-Grid desert cabin

I'm in much the same situation as Tony, but on the other side of Canada and with all the bells & whistles: electric 'frige and 1/3 HP water pump. I agree completely with what he and Bill have said, and add from my own experience that the 'frige uses 1.6 kW/hrs per day +/-. The water pump is a big draw on start-up and runs at 800 watts, which is far more than the "1/3 HP" rating; AC motor ratings are deceptive.
In addition to that we have a 1 HP 'digester' pump for sewer, which runs about 1 minute per day and so is inconcsequential. The biggest user is the necessary comp, which sucks up 90-200 watts per hour depending on what it's doing. The satellite system along chews 25 watts per hour doing nothing. We shut off all non-essentials when not in use.

The system: 700 watts panels (needs more), Outback MX 60, 320 Amp/hrs batteries (needs more), Outback FX 3524 inverter, Honda 2000 generator (plus others). A good day will see 3 kW/hrs total production.

Dave Angelini

Re: Advice for Off-Grid desert cabin

The OP really needs to state a budget to go any further than the advice given. Even though he may not know what he wants there has to be a number.

With a dollar figure I would go down the strategy path of making the system expandable. Everyone starts somewhere and there is always a basic level of comfort that only that person can answer.

I have gold mining camps all over my property where people "lived" a hundred years ago. I would have a tuff time living like that and my wife would have left me decades ago if I insisted. I lose customers sometimes on going down this path. It is just so rewarding when they come back and tell me what XYZ Solar sold them and nothing works right. Level of comfort and budget is where you start. Sometimes it can't be done! There is a very high failure rate when you cut corners offgrid!

BB.

Re: Advice for Off-Grid desert cabin

HairFarm,

By the way, looking at your pictures--it appears that the cabin and property may have had utility power at some time--and are those power poles in the background?

For the amount of power it sounds like you want to use (perhaps, only a first--live there, build out with modern low energy home)--utility power may be the cheaper solution (even if they charge you $x,000 of dollars to reconnect your power).

You can, later, always converter to full off-grid solar for emergency and/or change in lifestyle. Having utility power while you work on your conservation--is a very cheap and practical way to experiment with Off-Grid power consumptions with the backup of having "cheap" utility power. Plus, the property may be worth more if it has utility power available (if you ever decide to sell).

But, if you have grid, and it is reasonably reliable--then going with a Grid Tied solar system (no batteries) may be a better solution... If this is in the US (various rebates/tax credits, and your utility supports some sort of reasonable net metering)--you could get your GT power costs down to $0.10-$0.20 per kWhr...

In California--those cost levels are very competitive with the costs of utility power--and if you use more than "base tier" level power (all electric, A/C, well pump, irrigation)--it can actually cost much less than Utility power (which is in the $0.44-$0.60 per kWhr in some plans).

-Bill

icarus

Re: Advice for Off-Grid desert cabin

Good eye Bill,

That is a utility weather head drop coming up through the roof!

As Bill suggests,, off grid solar will cost you about double per kwh than grid tie.

Tony

Hairfarm

Re: Advice for Off-Grid desert cabin

Thanks so much for all of the information. Very thorough...almost too thorough

I'm not sure how many kWhrs we'll need. But maybe if I provide more details about what we have and what we "need" to survive in the desert, some of you may be able to assist me further.

1. We will not be living here full time. We'll be staying here about two weekends every month, roughly.
2. After reading your posts, I have now decided that propane should be utilized for some appliances instead of electricity. Like a cooking stove and possibly refrigeration(?)
3. We will build a 6 foot water tank stand for our water tank using gravity to supply water to toilet tank, shower, and two sinks. Or should we just keep the tank on the ground and use and electric pump to pump the water to our toilet tank, shower, and two sinks? Questions, questions.
4. We'll need some sort of cool air conditioning because of the 115 degree heat in the summer time. I think a company makes a solar swamp cooler(?)
5. We'll need heat during the winter. Propane? Wood? Solar?
6. Yes, the property has already been wired. There was grid power to the property at one time, but the poles were removed after the cabin went into extended vacancy. So, now no grid power.

We will still need electricity for:
1) 1/2 hp electric water pump from outdoor tank if we decide not to use a 6' water tank stand.
2) small refrigerator (I'm still confused about this - Propane or solar)
3) laptop computer
4) indoor lights
5) radio and small tv
7) water heater - btw, what's the best way to heat water? Is there an energy efficient solar water heater or propane water heater?
8 ) coffee pot
9) microwave oven - we could probably do with this for awhile.

Our budget for everything listed will be about $15,000 I'm not sure how much the electrical company will charge us to install two poles and an electrical line to our cabin.

I am quickly becoming aware of my limitations. Basically, I'm struggling to grasp much of the information some of you have provided in your posts. To be honest, electrical knowledge is not my strength. I'm embarrassed to say just trying to wrap my head around amp, watts, volts, inverters, kWhrs, etc. is a challenge.

Does anybody have information or a diagram that would help electrically-challenged simpletons like myself understand the solar system better?

Thanks again for the informative posts.

Cariboocoot

Re: Advice for Off-Grid desert cabin

Question: what is your water source? That makes a difference in what kind of water system you set up, which is separate yet connected to the electric system.

FYI: I calculate that an electric stove can use in one hour what we use in one week here!

My quick 3 rules of thumb:

1). Inverter wattage is a function of total potential load (everything that's likely to be on at the same time).
2). Battery amp hours are a function of usage between re-charges (watts per day divided by battery voltage - without drawing batteries below 50%)
3). Solar array wattage is a function of recharging batteries (must provide 5%-10% total battery amp/hr rating for a good charge rate and be oriented to have sufficient charge time).

Making the system expandable is a must. If you want to keep within budget, start with an inverter/battery set-up and a small generator for re-charging or supplementing such panels as you can afford (assuming you want to stay off-grid, for whatever reason). In any case, a back-up generator is a must for off-grid (and sometimes for on!)

You really are going to get the hang of "amps * volts = watts"!:D

icarus

Re: Advice for Off-Grid desert cabin

First,,, call the power company!

For all the things you are talking about doing,, grid power is probably going to be way cheaper. As I stated earlier,, you have to reduce your loads dramatically! Everything that creates heat with resitance, coffee pot, cook top, oven, toaster, electric water heater, hair drier, space heater etc. is a HUGE draw on any PV solar system,,, especially one with batteries.

Second,, where you live it should be a no brainer for solar hot water year round. A simple diy system would provide enough hot water with very little or no outside energy input. (Find the solar water pumping thread in this forum for some info)

You ac is going to be a killer. A evaporative swamp cooler will help,, but you must find the MOST efficient air conditioner. There is a recent thread in the energy conservation thread about a very efficient ac system.

The question is how does the water get into the 6' gravity tank? 6' of elevation will provide almost no pressure to run much of anything,, including a showerhead. (6'~3 psi!) Most demand water heaters won't run with that low pressure. (Demand propane would be a great suppliment for solar hot water.

As I stated before,, we live on very little electricity,, it looks like you loads would be in the ball park of 6-10 times ours. For the record,, we have 300 watts of PV and ~500 ah(12vdc) of batteries. If you were 6 times the loads,, you might need say ~1.5-2 kw of PV and 1500 ah of 12vdc batteries.

This might add up to a system cost of something north of ~$8000-10,000, for the panels alone, double that at a minimum for wiring, inverters batteries charge control etc. Add to that back up generator,,generator powered charger etc and I could see this system topping $20k without batting an eye. This for a system that you will have to replace the batteries every 3-10 years depending on usage, you are in a hot climate so battery life will be shorter,, this replacement might run a couple of thousand depending on the batteries you buy.

So, as I said, consider calling the power company, or if you are only going to use this a couple of days a month,, you might be way further ahead to use a small generator, and perhaps a small battery bank for lights at night,, coupled with a propane fridge.

Good luck,

Tony

BB.

Re: Advice for Off-Grid desert cabin

To play devil's advocate--what would it cost for Utility Power...

Let's try two power levels. One at 100 kWhrs per month @0.12 per kWhr.

The other, 600 kWhrs per month @0.20 per kWhr (California level rates).

Lets assume the power company charges you $4,000 to re-install the drop to your cabin. Assume 20 year "life" (20 years is a good time period for life of solar equipment).

$/kWhr = $4,000 + 100 kWh/mth * $0.12/kWhr * 12 month/yr * 20 yr / (100kwhpm*12*20) = $0.29 per kWhr

$/kWhr = $4,000 + 600 kWh/mth * $0.20/kwhr * 12 month/yr * 20 yr / (600kwhpm*12*20) = $0.23 per kWhr

So--based on two different usage sanarios (one, low usage, another low average usage)--you are looking at $0.20-$0.30 per kWhr (at current rates)...

Even with $4,000 power company charge (no idea if this is correct or not)--you are still 1/5 the price per kWhr for off-grid power (at today pricing).

Regarding solar and a weekend home... Generally, solar "makes more money" for you if you are their full time--or at least ~9 months of the year.

If you are there only on weekends for 20-30 weeks of the year--solar because more expensive because you are not using all of the power generated (normally, you can only store ~3 days of worth of power with off-grid solar). So--either you design for full time living (not cheap), or undersize your solar panels and oversize you battery bank (charge during week for weekend use--limited, if any, cost savings--batteries are not cheap, may not last as long if deep cycled, and you may still need a minimum amount of solar panels to properly charge the batteries and/or genset+fuel backup).

Regarding A/C use... Heavy insulation roof/wall/double pane windows/etc. + summer shade + a Sanyo "Mini Split" system might be even possible for solar off-grid use.

-Bill

niel

Re: Advice for Off-Grid desert cabin

hearing that the poles were removed i'm wondering who paid for their installation and was money refunded because of their removal?

mike95490

Re: Advice for Off-Grid desert cabin

I'll stab some of these questions.

Hairfarm wrote: »

3. We will build a 6 foot water tank stand for our water tank using gravity to supply water to toilet tank, shower, and two sinks. Or should we just keep the tank on the ground and use and electric pump to pump the water to our toilet tank, shower, and two sinks? Questions, questions.

Where does your water come from ? Well - how deep. Trucked in ?
I'd try just a hand pump, to get from ground level to 10' tall. 6' won't give much
pressure in the shower @ 5'6".

6. Yes, the property has already been wired. There was grid power to the property at one time, but the poles were removed after the cabin went into extended vacancy. So, now no grid power.

PG&E wants $7,000 per pole, every 120' . I just got that figure from them 2 months ago.

We will still need electricity for:
1) 1/2 hp electric water pump from outdoor tank if we decide not to
use a 6' water tank stand.

1/2HP is BIG

7) water heater - btw, what's the best way to heat water? Is there an energy efficient solar water heater or propane water heater?

Look at a drain-back solar thermal water heater. It needs water for your pump, and may need a shade cover for when you are absent and system is idle (prevent overheating)

9) microwave oven - we could probably do with this for awhile.

Microwave is about 50% efficient, getting heat into food, the rest goes to the cooling fan with the big vent at the back. (If I recall correctly)
One thing i want to look into is Induction Heating stove tops/hot plates. Looks like about 80% or more of input power, goes into actual heating.

Good Luck

dwh

Re: Advice for Off-Grid desert cabin

Is the water being trucked in? If so then a swamp cooler, while it will work very well, might end up using too much water.

How far out in the desert is this place? Are there any neighbors who can see it at night when some other neighbors drop by and steal your solar panels, generator, water, water pump and whatever else catches some desert rat's eye?

That place looks pretty small. If it were me I'd just pretend it was an RV and set it up that way.

* 12v RV water pump with accumulator.
* 12v lighting.
* Propane fridge, stove, heat and water heater.

* Propane generator, not too big. 2manytoyz (a regular on these forums) loves his Yamaha inverter gen, and this company mods them (with full Yamaha warranty) to run on propane (and/or natural gas) as well as gasoline:

http://www.yamaha-propane-natural-gas-generators.com/

2manytoyz says his Yamaha 2400 will run a little 5k btu a/c no problem, but I'd probably go with a 3000 and a bigger (energy star) a/c unit.

* A couple of 100amp/hour batteries to run the 12v stuff and absorb the extra output from the generator - that way you could turn the gen off when you weren't running the a/c.

* An inverter to power 120v stuff off the batteries.

Are you going to leave food in the fridge when you aren't there? If so then you'll need a propane tank at the site. Personally, I'd probably just leave a dual 10 gallon rig with auto-switchover (RV style) and haul up 1 full tank to swap out every month or so.



You could probably just buy a used trailer and strip it out for most of what you need.

Hairfarm

Re: Advice for Off-Grid desert cabin

mike90045

My water will come from an outside container. Now I'm beginning to think I leave it at ground level when installed and use an electric pump to get it from the tank to the toilet tank, sink/s and shower. What power rating pump would you recommend if 1/2hp is too big and who makes it?

Based on many of the posts on this thread, I realize I may have been over thinking my energy needs. Since I'm only going to be there one or two weekends per month, I think I'm going to scale down. My batteries will have the entire week to recharge for the weekends that I'm visiting.

Just to get going for the short term, I've revised my list (for all thing solar powered) to:

1) A water pump from outside water tank to cabin. What size? made by who?
2) Power to recharge laptop battery, cell phone and power tools
3) Radio
4) Two or three inside lights
5) fan
6) energy efficient dorm-type fridge only to powered during my stays at cabin. Suggestions for models.

We'll be using a generator for battery/emergency backup. - suggestions?
I'm thinking this for charge controller - http://store.solar-electric.com/xaxwmp60amps.html thoughts?

For cooking - I'll use a propane system. Can I use propane inside the cabin?
For water heating, I'm still undecided because of cost factors
For cabin cooling, I'm looking into a self contained, solar swamp cooler - thoughts?
Heat - Plenty of blankets for now

I want to get used to living off of the grid. If I decide to pay the outrageous fees for pulling utility power, then all the better. But I really do want to see if I can handle "life off the power grid" first.

Btw, a friend had an extra KILL-A-WATT, so he gave that to me today. Thanks for the advice for that, BB. Also, I think I'll order all of the components direct and enlist the help of someone in my desert community with solar experience to help me assemble everything. There several who are already doing this. This will save some $$ on installation. Any down side to this instead of going with a pro?

I'll be sure to send some images when I start work on my cabin.

Thanks,

n3qik

Re: Advice for Off-Grid desert cabin

I will chime in:

1) A water pump from outside water tank to cabin. What size? made by who?

Look at RV pumps by Shurflo:
http://www.shurflo.com/pages/RV/rv_categories/potable_water/potableWaterPumps.html


6) energy efficient dorm-type fridge only to powered during my stays at cabin. Suggestions for models.

Look at Compact Refrigerators:
http://www.lowes.com/lowes/lkn?action=productDetail&productId=235882-47224-FRT045GM&lpage=none

I have/had both products.

icarus

Re: Advice for Off-Grid desert cabin

How does the water get into the outside tank? Rain water cistern? Trucked in? Wind mill pump? Deep well pump?

For weekends only I would consider a small Dometic RV Fridge running on Propane. Not the most efficient set up,, but the cheapest to run on the week ends. You can find little under the counter models,, and if you add insulation to the case,, and leave them full of cold water they will use little propane to keep it cold during the week. The problem in hot climates with fridges is that they take a long time to get cold if you use them only on the week end.

Yes, you can use a gas (propane stove) inside the house, just make sure you buy one that has standing pilot ignition. Hot surface ignition requires lots of AC power. A direct vent gas space heater takes up little space and is fairly efficient,,, vents directly out the side wall, and uses no power at all. Empire or Cozy type heater.

You biggest cooling advantage will be from planting trees to shade the house,, add awnings to shade the house and windows, add attic insulation etc.

Tony

BB.

Re: Advice for Off-Grid desert cabin

I would be very careful of "dorm style" fridge and assuming it is energy efficient... From what little I have seen, they may use 1/2 the power of a full sized fridge, but only store 1/5th the capacity. Many (all) that I have seen do not have an Energy Star approval.

If you want to do it your self--and don't need a freezer section--converting a chest freezer to a fridge (basically an thermostat--ectomy) works pretty well and uses 1/4 the power of a regular fridge (I think I said this earlier--getting old and lazy--a terrible combination :roll: ).

Otherwise, go "RV" and use a propane unit until you are there full time.

-Bill

DagoRanch

Re: Advice for Off-Grid desert cabin

Just an observation, I can see by the pictures and description that this is a "low-desert" environment. But exactly where? It may make a difference on whether a swamp cooler will even work for you. Here in Arizona swamp coolers become pretty much useless during the months of July, August and part of September during the seasonal shift in weather patterns known as the "Monsoon-Season". Dew points above 50 degrees are commonplace during this time and render swamp coolers useless, especially when dew points get above 60 degrees. The air needs to be really dry for a swamp cooler to provide relief.

Now if this property is in western Arizona/California it's more feasible as that seasonal shift seems to stay away from that area, the farther west you are, the better off humidity wise.

Hairfarm

Re: Advice for Off-Grid desert cabin

Thanks all for the suggestions. We will be around the 29 Palms, CA area. It will be relatively dry all year long. A swamp cooler should work very well for us.

To answer a previous poster: We have a water tank and will have water shipped in until we can get around to digging (and saving for) a well.

Here is an idea I'm leaning toward:
http://www.livingonsolar.com/solar-cooling-video.html

Free PDF instructions:
http://www.livingonsolar.com/solar-cooler.pdf

Thanks again for everybodies input. This board has made this so much easier for my wife and I.

I'm still wondering what many of you off-the-gridders are using for heated water?
And one more thing. Conventional toilets or composting?

HF

icarus

Re: Advice for Off-Grid desert cabin

If you are having to truck in water,, the idea of flushing money down the drain sounds kind of crazy. On the other hand,,,I have had a bunch of (not very good) experiences with composting toilets. Every one that I have work with REQUIRES (even though they say they don't) a heat source to run very well,, using precious energy.

What is the matter with an old fashioned dug out house? Without the introduction of water from flushing,, a well designed outhouse can be odor and pest free, doesn't require any energy or waste water to run, and won't pollute the water. (Especially in such a dry climate!)

As I suggested earlier,, simple flat plate collector circulating hot water,, backed up with a demand Paloma/Rinnai/Takagi water heater is what I would do.

Tony

PhilS

Re: Advice for Off-Grid desert cabin

Hairfarm wrote: »

Thanks all for the suggestions. We will be around the 29 Palms, CA area. It will be relatively dry all year long. A swamp cooler should work very well for us.

To answer a previous poster: We have a water tank and will have water shipped in until we can get around to digging (and saving for) a well.
my wife and I.

I'm still wondering what many of you off-the-gridders are using for heated water?
And one more thing. Conventional toilets or composting?

HF

Swamp coolers should work well in your area but they DO use a lot of water. Since you will be trucking it in for the time being, you may want to consider the cooling system recommended by Dave Sparks here http://forum.solar-electric.com/showthread.php?t=5104 (you've probably already read it)

Having used evaporative coolers for decades, AND having a limited water supply (as you will for awhile), I've taken Dave's suggestions and this morning picked up my new Sanyo 11,900btu mini-split from the FedEx terminal. Hope to get it installed next week.

Yeah, it costs more. But it cools better and uses no water. The smaller 8000btu unit like Dave got should be enough for your cabin. AND it'll run from a moderate sized solar system.

The bigger concern I see from your photos would be theft prevention. A nice array of panels is an inviting theft target, and you won't be able to disguise or hide yours behind trees and it sounds like you won't be there most days. Do other neighbors have solar arrays too or would yours stand out even more?

Oh, and: flush toilets (the low-flow 1 gallon type, and 'if it's yellow, let it mellow'. Hot water is from a propane water heater.

Phil

dwh

Re: Advice for Off-Grid desert cabin

PhilS wrote: »

The bigger concern I see from your photos would be theft prevention. A nice array of panels is an inviting theft target, and you won't be able to disguise or hide yours behind trees and it sounds like you won't be there most days. Do other neighbors have solar arrays too or would yours stand out even more?

Phil

Yea, this was one of the first things I mentioned when I saw that photo...

I spent 5 years living in Palm Springs, so I know the area - there are a LOT of thieves out in the California deserts (and meth heads, and meth labs, etc.). Thieves pay attention - if you are hardly ever around they *will* eventually catch on to that.

My son was in the USMC and was stationed at 29 Palms, and they had lots of problems with desert rats...even on restricted areas used for live fire gunnery, they had to chase off the ones who come around collecting brass.

I also have an Aunt and Uncle who live out north of Morongo - they have water trucked in (which is why I asked that question) and they *can't* drill a well. I don't remember offhand the exact reason, but it's either that there is no accessible water table, or someone else has the water rights or something along those lines.


I would be *very* leery of putting anything expensive in a building out in the middle of the desert - unless there are neighbors close enough to keep an eye on things...but even then if they aren't very close they might not notice the guys loading up a truck at your place at 4am.

BB.

Re: Advice for Off-Grid desert cabin

There was the "classic stolen house" from 2003:

The troubles of the world, however, caught up with him. Sometime in the past two months, somebody stole everything inside Miller's house -- and then stole the house.



Investigators and neighbors say it could have taken a day or more for thieves to deconstruct his 10-by-20-foot prefabricated home south of Placerville, yank a well pump from 625 feet below ground, rip off his 600- pound generator and haul away his 2,600-gallon water tank.
All that's left on the property are pads where the house and a tool shed once stood. Thieves made off with everything from Miller's wife's toothpaste to a rope sitting in the bed of a 1976 Ford pickup that doesn't run -- which Miller guesses is why they left the truck but stripped its four balding tires.

I don't think they ever found the perp... However, they did get donations to replace much of the physical objects.

-Bill

Hairfarm

Re: Advice for Off-Grid desert cabin

The smaller 8000btu unit like Dave got should be enough for your cabin. AND it'll run from a moderate sized solar system.

Can you please send me a link to the item above. I'm having a problem locating it. What is the wattage for it?

As I suggested earlier,, simple flat plate collector circulating hot water,, backed up with a demand Paloma/Rinnai/Takagi water heater is what I would do.

Tony, Can you provide a link to what you've described above?

Hot water is from a propane water heater.

Phil, can you provide a link please?

In the Wonder Valley community I have three friends that live up there around me, and will look out for my property. Also, I am paying a retired marine $25 per month (many in Wonder Valley do the same thing) to check up on my property daily.

Still, I am concerned about theft. But at some point I have to commit if I want an enjoyable place to vacation at, right? I don't want to wait until retirement to install all of my off the grid hardware. Isn't there a way to secure solar panels or scare off speed freaks?

*sigh*

HF

icarus

Re: Advice for Off-Grid desert cabin

Here's one link,,, more if you do a search in the "solar water pumping" threads. Do a google search for solar hot water,, there's tons of stuff out there,, DIY stuff is pretty easy to do if you don't have serious freeze issues. http://forum.solar-electric.com/showthread.php?t=4818

As for water heaters,

http://www.rinnai.us/tankless-water-heaters/

http://www.palomatankless.com/ (Too bad they don't make the PH 6-12 legacy series,,, great for off grid applications)

http://www.takagi.com/ Great for grid applications,, but like the Rinnai's they use a bit of electrical power

http://www.boschhotwater.com/ Some people swear by Boschs,,, others swear at them. I'm sort of in the middle.

Tony

PhilS

Re: Advice for Off-Grid desert cabin

Sure HF, here's a link to the smaller unit that Dave installed (copied from the thread I linked to above):

http://www.minisplitsystems.com/cgi/display.cgi?item_num=09KHS71

Here's the one I'm in the process of installing (but probably bigger than you need... or maybe not :roll:

http://www.minisplitsystems.com/cgi/display.cgi?item_num=12KHS71

If you HAVEN'T read the thread I mentioned, it will give you new insights into cooling.... it did me.

Phil

dwh

Re: Advice for Off-Grid desert cabin

Article about solar panel theft:

http://www.offthegrid.com/offthegridliving/solar-panel-theft-on-the-rise/


The Bryce Fasteners they talk about in the above article:

http://www.brycefastener.com/default.asp


Another way is pretty simple; use stainless steel hardware, and hit each nut/bolt with a weld of stainless steel wire using a MIG welder. Even better if the mounting rails are stainless as well, so you can weld the bolt heads to the rails as well as the nuts.

This is absolutely what I would do.

The only way to get it apart is to use a grinder to cut it apart. That's not difficult to do of course, but it's time consuming, noisy (a high pitched whine that might carry quite a ways) and at night would create a nice light show of sparks.

If it's well thought out ahead of time, it should be damned near impossible to pry on the mounting in any way that will get the panels out without destroying them.


This still won't stop them from stealing your water pump, charge controller, inverter, batteries, appliances, propane, water, and anything else that isn't bolted down and can be sold for a few bucks.

The daily eyeballing by the ex-Marine is a good idea, it'll let you know pretty quickly that something has happened - AFTER it happened.


A good investment might be an alarm system hooked up to some seriously loud siren and some flashing lights. Once they get bit by that, they might just not bother again. Then again, if they've got the stones for it, they might just steal that too.

icarus

Re: Advice for Off-Grid desert cabin

If you are really remote, you are indeed at the mercy of your local neer-do-wells. Chaining stuff down locking it up may keep you from being cleaned out,,, but you still may have to deal with random acts of vandalism.

I used to worry about all that stuff,, but now,, after 50 years with only one break in (that was a winter traveler who broke in to get warm,,,,made tea,, left no note,, no damage). I lock up when I leave for more than a few days,, but don't go to crazy. I do buy insurance against theft, but it is pretty minimal coverage,, mostly covering outboard motors that are commonly stolen.

Occasionally we will have a band of thieves who run around on snowmachines pulling large sleighs. They tend to hit the built up cottage lakes nearer to town,,, and they are almost always caught. Most criminals are the sharpest knife in the drawer.

Good luck,

Tony