Tiny Houses

You know he's gonna have to pave the driveway to get the Tesla in, that assumes he is not going to opt for the SUV model. The landing pad for the Bell is gonna take some clearing and hell want landing lights for when he comes in at night. Will need to build a nice garage to keep the Tesla in. Probably also gonna need at least a 2000 sq ft servants cabin for the pilot, house keepers and other staff.

Ah - a nice little 600sqft get away in the woods...

If you want to turn the thread into a joke, fine, have at it.  The original idea - more of a question really - was how to set up a small weekend cabin with off-grid solar and a backup power source using practical off-the-shelf technology.  If you want to debate propane safety or survivalism or making your own fuel or designing a heat/power system that you'd need to be an engineer to operate, I'm not all that interested.  But by all means enjoy yourselves.

Adk Jeff wrote

If you want to turn the thread into a joke, fine, have at it.  The original idea - more of a question really - was how to set up a small weekend cabin with off-grid solar and a backup power source using practical off-the-shelf technology.

Not to make a joke of it, but this thread went off the rails form the beginning.  If you want to get off the grid for a winter weekend all you need is a wood stove and a box full of AA batteries for LED lamps.  The really isn't any affordable off the shelf technology to go off the grid with all the stuff you take for granted in a typical modern house, at least not on a way you could confidently leave every week.  The closest available equipment is marine stuff, like small generators and tiny solar cells to charge batteries critical for instrumentation and radios, but most people think that's about the same as camping. Almost everything mentioned in this whole thread, including fuel oil and LP boilers, and especially solar PV, is designed to require a reliable grid connection.  You can make it work off the grid, but you will spent every waking hour Magyvering it.

MM          

PeeTex wrote

You know he's gonna have to pave the driveway to get the Tesla in, that assumes he is not going to opt for the SUV model. The landing pad for the Bell is gonna take some clearing and hell want landing lights for when he comes in at night. Will need to build a nice garage to keep the Tesla in. Probably also gonna need at least a 2000 sq ft servants cabin for the pilot, house keepers and other staff.

Ah - a nice little 600sqft get away in the woods...

No need for a pilot, but do you know any stationary engineers looking for work in the north country?  I'll need 4 for 24/7 coverage.

MM

This is true.
Off grid in a cabin is a step up from camping. Your going to have to work at it. I would think parking an RV trailer would be the cheapest way as these are already set up to be off grid. If you added a few solar panels to keep the batteries up and an air compressor to blow out the water lines before you leave, it might work well - and you would fit right in with the local clientele. I have no experience with RVs but with boats, it worked well,

Milo Maltbie wrote

There really isn't any affordable off the shelf technology to go off the grid with all the stuff you take for granted in a typical modern house, at least not on a way you could confidently leave every week.

So do you think a solar system like this paired with batteries and a back-up gen like this would not work?  That's probably a $15K to $20K system to set up, but if you have to pay the power company to set a transformer and run line, then connecting to the grid may not be much cheaper. Harv, did you have to pay National Grid (or NYSEG or whoever you've got up there) to connect to your cabin?  At a minimum you must have paid for the cost of the line from the pole to your cabin.  I know you dug the trench yourself, what would that trench have cost if you had a contractor do it, $10/foot?

Adk Jeff wrote

Harv, did you have to pay National Grid (or NYSEG or whoever you've got up there) to connect to your cabin?  At a minimum you must have paid for the cost of the line from the pole to your cabin.  I know you dug the trench yourself, what would that trench have cost if you had a contractor do it, $10/foot?

How far do you want to be back from the road?  I am about 500 feet back which (I was told) was at or just beyond the limit. If you go too far, your voltage drops and and you end up burning out your water pump.

So my guy told me you can put in a transformer which is a PITA because you are working with National Grid or at that length you can buy the mega wire (like an inch in diameter) and bury it.  Was probably a bit more expensive but underground you never have to worry about downed lines on your land which are your responsibility not the power company.

We had a decent amount of frontage and were lucky that we had a POLE in the right spot. Perfect spot really.

Contractor dug the trench and I can't remember how much it was, but it was way less than $10 a foot. We included a conduit and a phone line too.  I THINK I am remembering 2500 for everything including the wire at $2/ft.

How deep is your lot, how far do you want to be back from the road? Closer is certain cheaper, less trench, less wire, less plowing. Plowing is a big one as it is obviouly not a one time thing. I think I remember your lot is not steep. Big bonus there.

Up at 1900+ it is ledgy and I was lucky to be able to trench at all.

Look at the specs of the system. I will bill you later for the engineering ;-)

Using the NREL solar calculator you can expect to get about 1/2 the output the manufacture states (using Harvey location as a reference). This is enough energy to run 2 100 w light bulbs 24-7 but you will need to rely on the batteries over night so just to get a feel, maybe 2 75w bulbs. That means the generator is going to run a lot. Maybe most of the time. The generators guaranteed life is only 2000 hours, or 83 days. It is not meant for a primary power source.  Dig a trench, you will be glad you did.

The trench is cute and all but it assume you actually have power access at the road.  Lot's of places in the Adirondacks where that isn't the case.  I looked at quite a few properties where the prospect of the utilities putting in lines was a pipe dream.  Not enough people to hook up to make it worth their while.

I wrote a long post earlier giving some positive feedback to Jeff, but apparently this thread rejects positive feedback.

Moral of the story.  Lots of off-the-grid places are using propane.  That's no mystery.  It's cheap and easy as long as you can actually get someone back there to fill your tank.  Some places I can think of that would be a challenge.

Digging an entire basement or foundation is not critical.  You could do what Harvey did (of sorts) and build a small sub-structure that has a basement and foundation and is heated year round to above freezing.  Insulate it well and have all your pipes and pump in there.  Then build a post and beam or connected structure on blocks.  Post and beam would be more stable, on blocks the structure will float and if it's connected to a structure with a foundation, they won't move the same.

Running on solar isn't a pipe dream either.  You may need to use less during the winter though.  I would suggest turning off the fridge and water pump.  Those freeze proof hand pumps are tried and true for something like this.  They are expensive, for a hand pump, but they are designed for northern environments off the grid.  Also if you forgo the running water in winter, you don't need the basement or the backup heat.  A properly sized woodstove will keep even a poorly insulated structure beyond warm even during the coldest days.

MikeK wrote

The trench is cute and all but it assume you actually have power access at the road.  Lot's of places in the Adirondacks where that isn't the case.  I looked at quite a few properties where the prospect of the utilities putting in lines was a pipe dream.  Not enough people to hook up to make it worth their while.

Jeff got a lot of good information from many of us, there was a little humor thrown in but for the most part, a lot of useful information. He or you may not like the facts but that's your choice. As far as paying to put in power - he asked about trenching so I think it is safe to assume there is power at the road.

PeeTex wrote

Using the NREL solar calculator you can expect to get about 1/2 the output the manufacture states (using Harvey location as a reference). This is enough energy to run 2 100 w light bulbs 24-7 but you will need to rely on the batteries over night so just to get a feel, maybe 2 75w bulbs. That means the generator is going to run a lot. Maybe most of the time.

Wait, that's per panel, right?  The system has six panels rated 285 watts each.  So 6 x 285 = 1710, and if I get half the output that's still 855 watts, or enough to run nearly 60 75-watt equivalent LED lights.  That refrigerator that Mike posted a link to uses 168 watt-hours per day, so I think there'd be plenty of power.

PeeTex wrote

The generators guaranteed life is only 2000 hours, or 83 days. It is not meant for a primary power source.  Dig a trench, you will be glad you did.

Agree, the gen is meant as backup, not primary.  But 2000 hours isn't necessarily it's lifespan, just the warranty period.  If you buy a tv set and it comes with a 12-month warranty, that doesn't mean it craps out after a year.  Even if it has to run 20 hours a week for 3 months in the winter, it's gonna take 8 years just to get to that 2000 hours. I suspect with regular maint, you'd get 20 years out of the unit.

As to the specifics of the small parcel I own, there's electricity nearby, but it's on the other side of the road and the line is 100, maybe 150, feet back from the road in the woods, not directly along the road.  I've never inquired from the utility, but I'm just guessing that it would be costly to get electric to my site.  I bought the parcel years ago (like 25 years ago) to camp on with the thought of one day possibly building a cabin or camp.  At the time I bought it, I lived in NJ (please don't spread that tidbit too widely), but not long after moved up. Moving up north kind of eliminated the need to have a camp, but I just hung onto the parcel anyway because I bought it so cheap that it's not really worth trying to sell.  Truth is, for my family, if  we bought or built something, Keene or Wilmington or Placid would really make more sense.  Anybody up north want to trade lots?

Adk Jeff wrote

PeeTex wrote

Using the NREL solar calculator you can expect to get about 1/2 the output the manufacture states (using Harvey location as a reference). This is enough energy to run 2 100 w light bulbs 24-7 but you will need to rely on the batteries over night so just to get a feel, maybe 2 75w bulbs. That means the generator is going to run a lot. Maybe most of the time.

Wait, that's per panel, right?  The system has six panels rated 285 watts each.  So 6 x 285 = 1710, and if I get half the output that's still 855 watts, or enough to run nearly 60 75-watt equivalent LED lights.  That refrigerator that Mike posted a link to uses 168 watt-hours per day, so I think there'd be plenty of power.

No - that's for all 6. Considering the sun angle, percent of cloud cover and the fact that there is no sun at night they will average about 25% of their rated output averaged over a day - more in early summer, less in late fall. Add in the loss of efficiency charging and discharging the batteries and converting to 110V AC and you are no where near rated output.

PeeTex wrote

The generators guaranteed life is only 2000 hours, or 83 days. It is not meant for a primary power source.  Dig a trench, you will be glad you did.

Adk Jeff wrote

Agree, the gen is meant as backup, not primary.  But 2000 hours isn't necessarily it's lifespan, just the warranty period.  If you buy a tv set and it comes with a 12-month warranty, that doesn't mean it craps out after a year.  Even if it has to run 20 hours a week for 3 months in the winter, it's gonna take 8 years just to get to that 2000 hours. I suspect with regular maint, you'd get 20 years out of the unit.

From Generac: Generac standby generators are specifically designed for extended run times, so having it run for a week or longer is definitely possible. Your only limitation is the fuel type, meaning the size of your propane tank or the supply of natural gas. We also recommend stopping the unit and checking the oil after 24 hours of straight operation and performing scheduled maintenance after 200 hours of operation. See your owners manual for instructions on how to check your oil. With proper maintenance, an air cooled generator could last up to 3000 hours of use.

So plan on changing the oil maybe twice/week and swapping out the unit every 2 years and that's if you don't live there.  

Jeff,
I sure you don't believe my "overly pessimistic" estimates but here is a tool from the National Rural Electric association (NREL): PVSolar Tool

Basically it says with a 1.7KW array in a normal residential installation using the weather data from Saranac Lake and North River as a location you might see about 150KW/H per month. A 100W bulb uses approx. 75KW/H per month if you ran it 24-7. I am not making this shit up.

Do we have an engineer in the building?

That array is 1.71 kW, just as Jeff calculated, 6x285 W.  That's a lot of solar power actually.

Yeah you'll probably get a 1/4 to 1/3 of that mid-winter, but that's still roughly 1/2 kW.  And you'll probably get 6 hours of full sun a day, so worst case, maybe storing 3 kW-hrs.  That's 3000 watt-hours.

You could also calculate your battery backup and see how many watt-hours in reserve you have.  If you are there two days a week, unlikely you are going to burn it all up, especially using the proper appliances.

I, personally, would forgo the inverter and use DC appliances, except for maybe the pumps where you possibly have high current draw and long wire routes.  Really DC becomes inefficient for long transport with high current (power).  Higher voltage is always better because the current the wire carries to deliver the same power is less, and current equates to heat loss via wire resistance.

Look into the pros and cons, you will lose some efficiency with an inverter (DC from the array to AC for appliances).  There is plenty of info out there on what the tradeoffs are for DC or AC systems.  Enough people have done this in recent years that it's not a great mystery anymore.

If the line is that close, I'd look into a grid connection and use that for stuff that will run all the time.  Then I'd look into a few cells and batteries for intermittent loads that you will only use when you are there, like lights and such.  There can be a benefit to using both.  There are solar systems that are far less expensive than the one linked earlier, but they are far simpler.

What Peetex and MM are saying regarding the work to run an off the grid home confirms what my buddy has told me. It's constant. He's a hippy Mercedes Tech so I guess he likes that shit. I'll just pay my bill

I know going green is the "thing" to do, but I don't really get it, or agree that it's such a huge savings. My current house is 1300 sq ft. I heat it for somewhere between 750-1000 bucks per year, and my electric bill on avg is 50 bucks /mo. Of course I had to put my pellet stove in but that was only 4K, I figure by the end of this heating season it will have paid for itself in 2 winters. How much cheaper can one live in the NE??

PeeTex wrote

Jeff,
I sure you don't believe my "overly pessimistic" estimates but here is a tool from the National Rural Electric association (NREL): PVSolar Tool

Basically it says with a 1.7KW array in a normal residential installation using the weather data from Saranac Lake and North River as a location you might see about 150KW/H per month. A 100W bulb uses approx. 75KW/H per month if you ran it 24-7. I am not making this shit up.

That'as probably about right.  150 kW-hr (it's not kW per hour, it's kW x hr) out of 30 days, you would have an average of 5 kW-hrs per day.  Assume about 6 hrs of full sun, and that's about 830 watt output, a little less than 50% output from the array.

I actually assumed less above.  There are general guidelines for estimating this as well.  Most are very conservative.

Question is, who would run a 2 x 100W light bulb for 24 hours a day?

First off you wouldn't use your lights more than 4 hours a day if you are there, even in the winter.  And there are plenty of lights give far more lumens per watt than a standard 100W bulb.  People still use those on the grid because they can afford to be inefficient, but that's why we are in a bit of an energy crisis.

MikeK wrote

Do we have an engineer in the building?

Several of them here I'm afraid.

MikeK wrote

That array is 1.71 kW, just as Jeff calculated, 6x285 W.  That's a lot of solar power actually.

Yeah you'll probably get a 1/4 to 1/3 of that mid-winter, but that's still roughly 1/2 kW.  And you'll probably get 6 hours of full sun a day, so worst case, maybe storing 3 kW-hrs.  That's 3000 watt-hours.

You could also calculate your battery backup and see how many watt-hours in reserve you have.  If you are there two days a week, unlikely you are going to burn it all up, especially using the proper appliances.

I, personally, would forgo the inverter and use DC appliances, except for maybe the pumps where you possibly have high current draw and long wire routes.  Really DC becomes inefficient for long transport with high current (power).  Higher voltage is always better because the current the wire carries to deliver the same power is less, and current equates to heat loss via wire resistance.

Look into the pros and cons, you will lose some efficiency with an inverter (DC from the array to AC for appliances).  There is plenty of info out there on what the tradeoffs are for DC or AC systems.  Enough people have done this in recent years that it's not a great mystery anymore.

If the line is that close, I'd look into a grid connection and use that for stuff that will run all the time.  Then I'd look into a few cells and batteries for intermittent loads that you will only use when you are there, like lights and such.  There can be a benefit to using both.  There are solar systems that are far less expensive than the one linked earlier, but they are far simpler.

Again - don't believe me, use the calculator. NREL is relatively unbiased, if they have a bias it is pro solar so I would tend to derate their estimates. Inverters are pretty efficient - about 96% but battery storage, not so much.

I used the 100W light bulb only as a method to help Jeff visualize how much power would actually be available. He would probably use CFLs which would use about 1/5 the power and also cut power every where else. But he would have to work at it. You basically need to be managing your power usage all the time.

Actually P, my estimate was more conservative than theirs.

Inverters have their issues, but cable losses are an issue too, like I said, if you have high current devices.  It's best to trade off what you are running and possibly use a hybrid system of AC for high current devices like pumps and DC for low current stuff like lights.

I would personally want high voltage DC, but it's not considered safe and I don't see any 48V+ systems available.

And yeah, I know it's not a lot of power.  That's why the whole system has to be engineered to accept solar.

You can afford to be wasteful with the grid, but with solar and batteries you'll use less because less is available.

To me, it seems a lot easier to do solar for a place that will be a weekend get-away, especially coupled with propane.  I'm not sure about the propane back up gen... that's the biggest ? for me.