Is there enough slope for a cistern to gravity feed the cabin?
It's so nice to have water even without power for some reason.
Off-grid property, need power
- Thread starter Daveyclimber
- Start date
Is there enough slope for a cistern to gravity feed the cabin?
It's so nice to have water even without power for some reason.
OP
Daveyclimber
Well-known member
No there is no slope. Cistern would be underground, water would be fed to house, shop and yard hydrants with a "booster pump" since the water isn't pressurized. If I for go the cistern idea due to cost then a traditional pressure tank will deliver water at the expense of the well pump operating more frequently.
We have a 450 square foot log cabin with 200 square foot stick built addition. (7 acres, lake front, backed up against USFS land, love it.) Northeastern Minnesota. The previous owner used the original log cabin in winters and heated successfully with wood. We have a 250 gallon Propane tank. 22 Cu Ft Unique propane fridge (glass shelves, interior lighting), gas stove and 2 gaslights. We only use it about 30 days per year, although the fridge is on full time from late May until early August.
My suggestion regardless of which way you go for the generator, is to have propane for cooking, heating, reefer, and possibly heat as a backup to your planned wood heat. It's affordable, reliable, quiet and will reduce your electric load. Propane delivery is going to have the same challenges as diesel delivery (it's by truck). The comment that you can schedule propane for "off season" is true, but your supplier will likely want a delivery charge if you are more than 20% full -- may or may not be worth it depending on the price and the fill. You propane supplier can and will size the tank for the demand and the weather (i.e. get the vaporization right).
I do think you should consider solar, even if it's limited. We have only a DIY starter system; 200 watts of PV and a Marine battery with a 400 Watt automotive generator. It handles LED lighting, charging cordless tools (only at the peak of the day) and i-devices. We have no major electrical loads, but we also can run LED lighting for several hours at night on the Marine battery. Daytime isn't a problem. This would not work for year round living or a full modern type of house (big TV, W/D, etc.) but the point is even a little bit of solar can keep you from running the gen at low load periods.
Prioritize septic over a well if funds are limited. We have a rain barrel system and carry in fresh water. We also can pump lake water.
My suggestion regardless of which way you go for the generator, is to have propane for cooking, heating, reefer, and possibly heat as a backup to your planned wood heat. It's affordable, reliable, quiet and will reduce your electric load. Propane delivery is going to have the same challenges as diesel delivery (it's by truck). The comment that you can schedule propane for "off season" is true, but your supplier will likely want a delivery charge if you are more than 20% full -- may or may not be worth it depending on the price and the fill. You propane supplier can and will size the tank for the demand and the weather (i.e. get the vaporization right).
I do think you should consider solar, even if it's limited. We have only a DIY starter system; 200 watts of PV and a Marine battery with a 400 Watt automotive generator. It handles LED lighting, charging cordless tools (only at the peak of the day) and i-devices. We have no major electrical loads, but we also can run LED lighting for several hours at night on the Marine battery. Daytime isn't a problem. This would not work for year round living or a full modern type of house (big TV, W/D, etc.) but the point is even a little bit of solar can keep you from running the gen at low load periods.
Prioritize septic over a well if funds are limited. We have a rain barrel system and carry in fresh water. We also can pump lake water.
Don't start with lead acid. it's NOT the most cost effective. Lithium is. pick a setup you can scale.
also I think wizard is wrong on chemistry. Li-Ion has the best $/kWh, especially if you go with used EV batteries. keep out of the top 10% (20% preferred) SoC for longevity. yes LiFePO4 will last longer, but cost is king here, and to win that game you need to play in the economies of scale sandbox.
look at MidNite solar for charge controllers, etc. they also sell pre-wired off-grid systems, so you don't have to figure everything out yourself.
has anyone in "town" considered a local genset instead of everyone rolling their own?a local grid of sorts? seems silly for everyone to buy the infrastructure over and over again.
also if I wanted heat AND had to run my own generator, it would be water cooled, and i'd plumb in an extra HX, and run a fan coil/radiators in my house. you're paying for the fuel, why not use the heat too?
adding a coolant/coolant HX means if you don't need the heat, the genset cooling system will function normally. if you do need it, bam, "free" heat. you could heat sink to a giant thermal mass (water tank) in your crawlspace/basement). seen those off-grid for wood boiler use. heat up 1000 gallons of water and use the heat as needed.
Bigbandguy
Well-known member
Interesting thread. I think you are on the right track by having multiple energy sources. Any solar at all would likely be enough to run LED lighting. Batteries and inverter near the panels and run the AC to the house to avoid some line loss. More than one diesel sounds like a good way to go and keep the EU2000 for emergency backup.
This forum: https://www.small-cabin.com/forum/ has many very experienced people on it who have faced the same problems you mention and come up with varying solutions, including some really ingenious ways of doing things. Good luck!
This forum: https://www.small-cabin.com/forum/ has many very experienced people on it who have faced the same problems you mention and come up with varying solutions, including some really ingenious ways of doing things. Good luck!
dcg9381
Well-known member
We're living in our shop currently. We use propane for hot water (and drying clothes). A 100 lb tank, which is "portable" lasts several months. It'd be my go-to for an off grid cabin... I have 2 tanks and I just keep them on rotation.
From owning RVs, propane fridges draw very little propane and there are models that can do propane and 12v dual.
From owning RVs, propane fridges draw very little propane and there are models that can do propane and 12v dual.
theoldwizard1
Well-known member
Then you have not watched many of the Will Prowse videos ! Crimp some connectors, connect them up correctly and you are done !
theoldwizard1
Well-known member
Cisterns or shallow wells can be tricky. First, they will run out of water even a mild drought unless you are on a spring. Second, they are very susceptible to surface contamination and bacteria.
Expect to have a large filter, carbon filter and UV treatment.
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theoldwizard1
Well-known member
Excellent suggestion !
Please note that Zeke is using a residential propane refrigerator, not an RV propane refrigerator. These work well !
OP
Daveyclimber
Well-known member
Cant see how the cistern would run out of water. A well would supply the cistern on demand with a float switch. Water will be consumed faster than it would likely "spoil" but filtration would be used regardless and I like the idea of a uv treatment. Thanks
OP
Daveyclimber
Well-known member
I usually work out in the sticks on BLM land. My travel trailer is currently set up with 2 100lb tanks which can last anywhere from 2 weeks to a month for each tank depending on temperature.
theoldwizard1
Well-known member
A cistern is nothing more than a tank, typically in the ground. It is often feed by surface runoff or runoff from a roof.
I've got a cistern next to my house. Fed by the runoff from the roof. The original pump in the basement sort of still works, don't use it. I have a submersible pump I've dropped into the cistern and used it to water plants. I've thought about tying the basement pump to the outside faucet.
I wouldn't drink the water, out of mine anyway. Would need to be sealed and that's not possible without a clean source of water.
Really the main reason to use a cistern is to capture rainwater (soft), or as a buffer for a low output well. I'm not sure if you'd save much energy over a submersible pump. Depends on the depth of your water table I suppose.
I wouldn't drink the water, out of mine anyway. Would need to be sealed and that's not possible without a clean source of water.
Really the main reason to use a cistern is to capture rainwater (soft), or as a buffer for a low output well. I'm not sure if you'd save much energy over a submersible pump. Depends on the depth of your water table I suppose.
Propane still is used as a refrigerant (R-290) as is the very similar 2-methylpropane/isobutane (R-600a). In fact, R-600a is the refrigerant of choice in household refrigerators today and R-290 is increasingly used in commercial and industrial applications. Propane and isobutane work well but of course are flammable. Essentially everything else that was safer and still remotely efficient is either already banned or on the list to be banned in the near future.
I have 2 2100 gallon concrete cisterns. One is fed from a spring and is used for outside water. The other is fed from a 520' well and in turn feeds the house. The well pump is controlled by a float switch. The house is gravity fed. The well pump only runs every 4 to 6 weeks.
When the power is out, I can go weeks with propane for heat and cooking and a gravity water system. A small gen set can keep the fridge going.
I'm not off grid, but when power goes out in the winter life goes on with little disruption.
If the OP cannot gravity feed the house, an on demand RV type 12V pump could easily supply pressurized water for the house. A gen set to run the well pump, a small solar system to charge one or two deep cycles, and LED lights would have him pretty comfortable. A propane cook stove, water heater, fridge and parlor stove would complete the set up.
When the power is out, I can go weeks with propane for heat and cooking and a gravity water system. A small gen set can keep the fridge going.
I'm not off grid, but when power goes out in the winter life goes on with little disruption.
If the OP cannot gravity feed the house, an on demand RV type 12V pump could easily supply pressurized water for the house. A gen set to run the well pump, a small solar system to charge one or two deep cycles, and LED lights would have him pretty comfortable. A propane cook stove, water heater, fridge and parlor stove would complete the set up.
WisJim
Well-known member
If you have electricity, I wouldn't use a propane refrigerator. Back around 1982, when we were totally off-grid, we bought our first PV panels so we could power an efficient electric refrigerator to save money on propane by replacing our propane fridge. And back then the PVs were over 10 times more expensive than now and LP was much cheaper, and today's readily available electric refrigerators are almost as efficient as our old super expensive Sunfrost was back then. Today it is better to avoid propane for refrigeration and run an inverter and battery system no matter how the batteries are charged.
OP
Daveyclimber
Well-known member
No, I will be using a standard electric fridge, maybe even a smaller unit and convert a chest freezer to a fridge for less used items.
OP
Daveyclimber
Well-known member
I have not read through every single response but here are my personal recommendations with reasons:
1) Batteries - Get flooded lead cells like the ones Rolls make - Last a lifetime. Learn how to use them, take care of them, you should get 20-40 years with proper care. There is a huge push for new technologies like LiFePO4 and the like ("They are so small!" etc) but these batteries lifespan is very finite, they are not rebuildable, and unless you are severely space or weight limited it makes no sense to do this. Personally, I like batteries that are "buy once and never again".
2) Generator - Responses recommending diesel genset are correct. Look at something like a MultiQuip Whisperwatt, a diesel genset made for continuous duty - ANYTHING that is "standby" duty will not last and will cost you more in the long run when you have to rebuild, replace, or repair it. Get a manual for it, taking care of the engine is like taking care of a compact tractor engine. If you could get by with relatively low power output for cheap, I am wondering if these ~7kW light tower trailers can be converted to generator-only - I suspect that they can - And these are usually rated for continuous duty and people sell them cheap all over the place due to it being configured as only a light tower. These newer diesel generators like the MQ's are more fuel efficient than the old military type/onan gensets you find, I consider fuel efficiency key and better fuel efficiency will mean a cleaner running engine with lower oil contamination rate and less heat.
I would size the diesel for 2x your typical power need; The whisperwatts and similar appear to be most efficient around 1/2 load and will easily beat out the roll-around standby models (i.e. a 12.5kW whisperwatt loaded at 6000W should be notably more efficient than a 6500W honda roll-around loaded at 6000W). Running it at half load also means significantly less thermal stress on the generator side, and since there is an inverse relationship between lifespan and operating temperature, this is a good thing.
I have seen MQ's and similar listed with 20,000 hours on them, original engine, still going strong, so if you get one at around 5000 hours that was well cared for and runs like a top, it should keep running that way if you take care of it.
3) Charging system for the batteries, inverter - Best to do as much research about this as possible and piece it together/architect it yourself. All of the "turn key" systems I have seen which are ready to just be plugged into batteries and a generator with zero knowledge about how it actually works fall into two categories - Great quality and expensive as hell, or poor quality and cheap. You can find good true sine wave inverters secondhand all over the place. Charging lead chemistry batteries is not rocket science.
Good luck. I am in no way an "off grid" expert but have specialized in electronics, including power electronics for past 20yrs all the way from the architecture level down to the semiconductor level so I have lots of opinions
We are on the same page.
Batteries will most likely be Crown or Rolls. It seems tempting to do LiFePO4 but the high initial expense for commercially assembled batteries is retarded. I'm also not real keen on building a battery bank with raw cells from China or much of anything from China for that matter.
Generator will absolutely be a diesel unit designed for continuous duty, a light plant generator may be a great idea for a backup emergency unit but probably too small for other needs. Obviously the generator would be sized to match the needs of the battery bank and inverter charger. My gut tells me somewhere around 7.5-8kw but may need more without wasting energy. My inclination right now to power a shop separately from the house using a mutiquip whisper weld, wired in to the shops breaker panel. I've rented them before and they are quiet and weld great and are portable which is useful for my line of work.
There are alot of new comers to the inverter charger game and seem very tempting because of their price point. Makes me leary though and I hope to stick with a Magnum, Victron or Xantrex that can start the generator automatically without having to scab together 3rd party components.
One issue I'm having trouble with is deciding to power the house and shop with one power shed or power my shop stand alone with a separate generator on an as needed basis but power the lighting in the shop with the power shed that would primarily run the house.
ihateminimumwage
Well-known member
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- Jan 26, 2012
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Don't rule out the light plants, especially for battery charging. You'll get 5-6kw, 1800rpm with a 3cyl Kubota, and cap regulated alternator. About as simple as it gets if you find one with a 2 wire remote start. With a diesel you'll want it right in spec to keep it loaded and not wet stacking.
We have a good wind storm blowing through right now. Power is out, and running the whole house with a 7kw Whisperwatt while I type this. Anything with a 2,3 or 4 cylinder Kubota will be bulletproof.
OP
Daveyclimber
Well-known member
Thanks for that input. I may integrate a light plant into the equation if it checks all the boxes. I'm a big fan of kubota engines myself though most of my experience is with the wg gas powered versions. Wet stacking is a concern and a big reason I dont want to go too big on generator size. The storm is mostly missing my location in St Regis.
OP
Daveyclimber
Well-known member
Awesome, thanks for the validation
CarBikeGuy70
Well-known member
Light tower plant is an absolute consideration. If for nothing else use as a standby when all else fails. When you do the math you will see that a 6kw diesel ( 1800rpm) is the way to go. Great fuel efficiency and ease of operation. Used units can be had for 750-850 dollars and will have low hours - may times under 2000. Rebuild on a 3 cylinder Kubota is around 10,000 hours. I know of one unit used by a large construction co. that has 32,000 hours on the meter and has never been touched- just basic upkeep. Mechanics just wanted to see how long it would go!! Diesel fuel is easy to store for use when needed.
dcg9381
Well-known member
Maybe you need the weight savings in a small RV, but even 19' RVs are built for 1-2 lead acid batteries. I've used those LiFEPO4s in motorcycles, they're great - but definitely not what I'm looking for if I don't need the power per unit weight/size.
I agree that lead acid is the most economical for self-maintenance.
However, if you look at PWRcell and Tesla options, they appear to by a type of lithium battery, they're warrantied for 10 years to 80% capacity... Pricey at about $10k (give or take). But they'd basically be "black box" battery power storage that self regulates and takes a lot of the engineering out of it..
if you're buying new, Li-ion is the cheapest per kWh stored and delivered, especially if you limit your DoD and SoC.
li-ion: 80-10% charge yields 70% usable capacity, with no penalty for sitting at any SoC in that range.
lead-acid: 50% DoD max yields 50% usable capacity, issues sitting at low SoC, plus large efficiency penalty for recharging, extended generator run-times to finish charge at 100% or equalize.
if you're buying used, and able to source a large quantity of identical cells at at a discount, well then you have to do your own math.
if you want to see the be-all, end all of off-grid homes, i think this qualifies:
https://057tech.com/solar
OP
Daveyclimber
Well-known member
The upfront cost of any lthium type battery is a non starter for me. Maybe down the road but it certainly isnt in the cards right now and I'm not necessarily sold on the technology. I have no doubt they are superior in some regards but they are relatively new technology almost all of them made in China from what I've seen. I'm good with low tech high reliability.
drivesitfar
Well-known member
interesting topic title so i'll see if I can catch up and learn and maybe have something to add later.
since you mentioned it's not in the cards what is your budget?
good luck!!
since you mentioned it's not in the cards what is your budget?
good luck!!
theoldwizard1
Well-known member
Concur ! One 20A 120V feed to the shop will run all your lights, power hand tools and battery charges.
(I don't agree with anything else you propose. Even the best lead acid batteries have a shorter life span than LiFePO4. To improve their lifespan you should not discharge them more than about 50%)
OP
Daveyclimber
Well-known member
I intend on using batteries from Rolls, rather give the Canadians my money than the Chinese. They off 6v batteries that specifically state 80% discharge. This is potentially what I intend to use.
OP
Daveyclimber
Well-known member
My budget has to include building a home, some iteration of a shop, power generation, well and septic. I realize to have a power generation system that covers all my scenarios would probably be 50k, which I cannot afford in one shot. So I will have to prioritize the generator and battery bank first and use componants on the inverter side that will allow adding solar as funds allow.
Davegvg
Well-known member
a used Onan/powertech diesel Rv genset will power a small homestead and keep a hybrid battery/ inverter charged up. You can buy them cheap out of wrecked Rv and they are awesome compact units.
The sweet spot units are
1. the Onan 8000 which uses a d722 Kubota and its an inverter meaning it runs at variable speed. I put 10's of K hours on them with little to no trouble.
2. the 12K unit a bigger kubota and is single speed.
3. a powertech 10K running a small cat - same ones in millions of thermo kings.
Couple 50 gallons of diesel in the back of a pickup each visit can run you a long time.
One of these with a moderately sized inverter and house bank can take you along way.
The sweet spot units are
1. the Onan 8000 which uses a d722 Kubota and its an inverter meaning it runs at variable speed. I put 10's of K hours on them with little to no trouble.
2. the 12K unit a bigger kubota and is single speed.
3. a powertech 10K running a small cat - same ones in millions of thermo kings.
Couple 50 gallons of diesel in the back of a pickup each visit can run you a long time.
One of these with a moderately sized inverter and house bank can take you along way.
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OP
Daveyclimber
Well-known member
On the idea of a light plant. I am checking out auctions for a potential purchase of a known good unit. If nothing else it will provide shore power for construction tools since most of my construction/wood working tools are not cordless and I don't want the expense of going all cordless. Additionally, my eu300is and eu1000i ain't got enough chooch to run a tablesaw and a compressor and maintain power for my travel trailer.
OP
Daveyclimber
Well-known member
I agree, looking to go with kubota, perkins/cat, yanmar or Mitsubishi and Isuzu powered units. What kind of features should I be looking for or be concerned with regarding the generator head?
OP
Daveyclimber
Well-known member
The whole LiFePO4 industry reminds me of snake oil sellers and gimmick devices to increase fuel mileage by 25%. Its too new and too many new players all relying on foreign components and technology. Just gives me a bad vibe
Davegvg
Well-known member
Everyone you mentioned is good, but the packaging with the powehead can vary dramatically.
the RV units are standardized.
The reason I picked RV units is that they come completely in an enclosure already packaged up you can toss the thing in a pickup bed.
On the powerhead you want to make sure its something you can can work on, you are looking for brushless if you can get it, and if brushed buy a couple of spares and belts for it when you pick the unit up. Some of the easier powertech replacement head can be pricey...
I have a full set of UOAs done on my kubota D722 mills- they wear incredibly slowly and well on modern oil I think I pushed one oil change out to 350 hours and still had serviceable oil from a 3quart sump , some of the kubotas are up to 1000 hour oil change intervals running lighthouses and traffic signs.
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