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BrianB
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# Posted: 8 Dec 2018 02:15pm
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So I bought a piece a property with a cabin and shop. Cabin is small but nice. Roughy 25x15 with a loft. I’ve explored some power options but end up uncertain with which path to take. I bought it for hunting but part of the deal was it had to be functional for my wife to come and relax since it’s in another state and she doesn’t want to be a widow all hunting season!
To run permanent power is about $30k (yikes), solar is gonna be about $15k per the contractor I spoke with which is expensive and I’m unsure of the efficiency. I thought I had it figured out with a echogen 15kw generator but then I realized it burned 2 gph of lp. That’s not doable for full time use.
So I’m thinking a smaller generator (Honda 3000?) with a battery bank? I need to power water pump for a catchment system, microwave, mini fridge, tv and satellite, small window unit when necessary, a couple lights and whatever other random little things.
Which path would you guys take? And what would a battery bank and inverter for something like that run me cost wise roughly?
Thanks for any help.
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slatecreek
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# Posted: 8 Dec 2018 03:11pm
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I think you should determine what your loads will be first. A few LED lights and phone charger or electric heaters, hot plates, and other power thirsty appliances. Propane heat or cooktop, wood stove would help downsize your electrical load. If the cabin has a small electrical load then a small solar system with a backup generator might do well. Make a list of everything electrical you plan on having and then go from there.
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slatecreek
Member
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# Posted: 8 Dec 2018 03:15pm
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I guess i should have explained, actual current loads. Heresa calculator to help size it.
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toyota_mdt_tech
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# Posted: 8 Dec 2018 03:27pm
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Brian, creeky member is a guy to talk too. You can probably do a combo ie batterys from solar and a smaller Honda EU2000i generator to supplement low light days. Using battery in the evenings (converted to AC) and the size of that system will determine how big of loads.
Obvious, larger solar panels, bigger battery bank, you may be able to not use the generator at all. But all that comes at a higher price too.
This forum is full of members well versed in just what you are trying to do. And getting info from them is a great way to not spend a bunch of money in wrong areas, but in the right area the first time.
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Borrego
Member
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# Posted: 8 Dec 2018 03:30pm
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FWIW, I just installed a solar system for our 24 x 24' cabin. Went high-end and it cost $7000.Powers house plus refer...Did all the labor myself, it's not that hard, particularly with the help available online nowadays...here, youtube, etc.
But yes, do a load calc first...
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BrianB
Member
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# Posted: 8 Dec 2018 03:37pm
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Thanks guys I did a load calculation to the best of my knowledge, based on values gathered online. I came up with around 2500 +\- watts without ac and 3500 or when running the ac.
I was thinking (and don’t make fun of me if this is wrong!!!) Honda 3000 generator to battery bank (how many and what kind is the question?) to inverter to panel? Am I on the right path at least?
Thank you
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slatecreek
Member
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# Posted: 8 Dec 2018 03:43pm
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For what the price of solar panels are going for today, i would add them to your system. Running a generator all the time can be a pain. I just bought 250 panels, solar worlds for $160 each. Charge controllers are available to accept solar and generator inputs to simplify your system.
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slatecreek
Member
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# Posted: 8 Dec 2018 03:45pm
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The 250 watt panels from a local electrical supply house. Check your local electrical distributors, save a ton on shipping bulky panels.
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Atlincabin
Member
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# Posted: 8 Dec 2018 06:54pm
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Six years ago I put a solar system on my cabin. Four 250W panels plus inverter plus 4 - 460Ah AGM batteries and various other bits and pieces. Total cost at that time was about $9k. Stuff is much cheaper now. That system is sufficient to run everything I need including regular-size (10 cu ft) reefer, lights, computers, small water pump and tools in my shop (table saw, chop saw, various hand tools) plus the occasional hair dryer, vacuum etc. I'm putting grid-tie solar on my house right now, 4kW system and the total cost is going to come in under $7k BEFORE the tax credit (of course, no batteries with this one). Contractor bids for the house were in the $15-18k range, so you clearly save by doing it yourself.
Absolutely solar is the way to go unless you live under a perpetual cloud. Remember you won't be running all those loads simultaneously - the key is calculating the kWh use overall. If necessary, add in a small 2-3kW generator for those time when you need more power or the sun quits shining for a couple weeks.
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offgrididaho
Member
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# Posted: 9 Dec 2018 12:34pm
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Good simplified schematic for what you want is here (courtesy of creeky):
https://bobolinksolar.com/new-diy-off-grid-solar-schematic/
Also good point about tax credits for solar 2019 might be last year for them
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Borrego
Member
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# Posted: 9 Dec 2018 02:43pm
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Quoting: Atlincabin Stuff is much cheaper now.
Yes it is ..... 6 - 350w panels, 8 - AGM batteries, all Schneider equipment for $7k
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BrianB
Member
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# Posted: 9 Dec 2018 03:32pm
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So my theoretical system of Honda 3000 to battery bank to inverter to fuse panel is not practical or even feasible? I could supplement a couple solar panels as well. Don’t need a terribly elaborate system.
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offgrididaho
Member
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# Posted: 9 Dec 2018 04:34pm
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(First a caveat, I'm not an expert here, still trying to learn myself).
I don't have any experience with AC off grid so don't know how to factor that in, you might have to plan on running the AC directly off generator when you need it. One thing to remember is when people talk about how many amp hours a battery has that's over a 20 hour period, so if a battery has say 105 amps capacity that means over 20 hours so you can't be drawing more than 5.25 amps (60watts @ 12v) per hour to get that capacity... if you were drawing 15 amps per hour you would have quite a bit less capacity than 105 amps, so those high draw items will drain batteries very fast (microwave or toaster is one thing since those may run 5-10 minutes at a time, but AC all the time is a different animal).
So if we ignore the AC side and you figure 2500 watt hours per day (which is about what I have figured for my summer use so sounds believable), that's 208ah per day @ 12v. If use lead acid batteries (which if you could go up to lithium you'd be a lot better off but they are spendy) you don't want to run them below 50% state of charge so figure you need at least 400ah of battery storage and then you would have to completely top the batteries off every day, better to have more storage than that.
To generate 200ah/day of recharging, if you have an inverter/charger that puts out 100 amps you're looking at running the generator ~3+ hours a day, every day (as you get closer to full charge your charger is going to put out less and less amps, but you want to try to get the full charge in there as it's better for the battery). Factor in how much fuel you're going to use and have to haul (this is big deal for us because everything has to go by boat then hand cart).
Regardless, to have power in the cabin you have to have a battery bank and an inverter (or inverter charger)... that part doesn't really change no matter what, the question is then how to charge those batteries, generator or/and solar.
To go solar only, you have to figure out based on where you are (i.e. how much sunlight you'll get) how much panel output you'll need to generate that 2500 watts per day if you don't want to use the generator at all (but you're still going to want the gen for cloudy days, emergencies, and probably the AC). FWIW my plan at 48 degrees north is 900+ watts of solar, which I hope allows me to never have to run the gen in the summer and maybe run it an hour a day on average in the off season.
You can start with generator only and then add serious solar as time and money allows. However, my opinion would be if you start generator only still add at least *some* solar, even if it's only a 100w panel to start with (you should be able to do 100w and small good MPPT charge controller for only a few hundred beans). This small amount of solar will do two important things for you: 1) it will maintain your batteries when you're gone, and even charge them back up to completely full while you're gone if you had run the batteries down before you left the last time and 2) solar is very good at getting those last few amps into the batteries and getting them completely, fully charged... you can use the generator to do the bulk charging but then shut the gen down and have the panel get you all the way to "float" (assuming you aren't already drawing batteries down again of course).
My two cents, worth less than that...
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offgrididaho
Member
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# Posted: 9 Dec 2018 04:36pm
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FWIW, here's my current schematic (after some helpful corrections from creeky, and with more changes I'm sure still to be made)
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BrianB
Member
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# Posted: 9 Dec 2018 05:03pm
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That is awesome awesome advice!! You laid it out like I haven’t read before and it explains sooo much. Thank you very much, sounds like it’s a no brainer to use some solar than. I really appreciate all the great advice from you guys.
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silverwaterlady
Member
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# Posted: 9 Dec 2018 08:10pm
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I have a question. How does one keep their batteries topped off in a cabin that is not used full time?
If you are not there to move the solar panels as the sun changes with the seasons or to brush two feet of snow off the panels how would you be able to leave the battery bank at camp?
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offgrididaho
Member
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# Posted: 9 Dec 2018 08:33pm
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IMO you don't have to worry about moving panels or anything, you have hopefully small or non existent draw on your battery bank when you're not there, takes just a little bit of sunlight every day (even if not direct / not angled perfectly) to keep your batteries topped up.
Don't know how you deal with the snow factor though... our build is going to be in coastal Washington where snow generally doesn't stick around. Perhaps a dedicated, sheltered lower angle panel (i.e. under a roof of some sort that keeps snow off but still allows low angle sun to hit the panel) to keep things charged in the winter?
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creeky
Member
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# Posted: 11 Dec 2018 05:03pm
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Or you have lithium batteries where they don't need to be fully charged.
Discharge to 60%. Turn off system. Go away and worry not!
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neckless
Member
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# Posted: 12 Dec 2018 07:14pm
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i have solar now ...but for 5 years i had a honda 650 watt gen it ran my tv, lights ..all i needed ... i had 12v water.... burn a qt of gas a weekend i use that geny so much that the throttle linkage wore out lol
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NorthRick
Member
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# Posted: 13 Dec 2018 02:18pm
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Quoting: silverwaterlady I have a question. How does one keep their batteries topped off in a cabin that is not used full time? If you are not there to move the solar panels as the sun changes with the seasons or to brush two feet of snow off the panels how would you be able to leave the battery bank at camp?
If you disconnect the inverter, the only draw on the batteries is the charge controller and self discharge. Both are pretty light draws and it doesn't take much sun or the optimum angle to maintain the batteries.
As for snow, it will pretty much reduce power out from the panels to zero. The best way to deal with that if you are in an area where snow sticks around for months at a time, and are unable to periodically clear the snow off the panels, is to mount them so you can set them vertical for the winter. With low sun angle and reflection off of snow covered ground, a vertical panel can actually produce more power than one tilted for max power at other times of the year.
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RiverCabin
Member
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# Posted: 13 Dec 2018 03:19pm - Edited by: RiverCabin
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What are you using for heat? If you are using wood heat as your sole method of heating, I'd get a Honda generator and call it good.
Our cabin was off grid for six years and we solely used a Honda EU200I. Since our cabin was used almost exclusively in the late spring to early fall, our primary usage was for a small window ac unit. The Honda ran the small ($98 Walmart) air conditioner with ease.
We never used a refrigerator then and instead relied on quality coolers. If you use a quality cooler (we used an Orca) you never had to worry about warm food.
I think everyone would have better answers if we knew roughly where your cabin is located and what the climate is in the area.
I also think you should look into grid power again. The electric company may have quoted you 30k but often you can run underground lines yourself or with a private contractor and save some money. Being on the grid would certainly increase the value of your property and would save you from some of the off grid headaches.
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LastOutlaw
Member
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# Posted: 22 Dec 2018 05:08pm
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I have a small cabin much like you describe off grid. I heat with a wood stove, I have a battery bank that I use during the day hooked to a cheap 2000 watt inverter to run a chest freezer that is converted to use a as a fridge, a tv, some regular 110 volt lights that have led bulbs in them.
At night I have a small honda eu2000I generator that I run to recharge batteries, run a window mount ac unit to cool one room down to sleep lights and tv off of. My fridge uses around 350 watts of power in a 24 hour period and I am extremely happy with it!.
I also have a shower stall that uses an ecotemp tankless water heater for hot showers. That has worked great for me as well.
At night when charging batteries and running ac, lights and tv, I will top off the generator with a gallon of gasoline at around 11PM and it will usually run until around 4 or 5 am then shuts off when it runs out of fuel. In the morning when I wake up I get back on battery power and the circle begins again.
In the winter when not using AC It will run all night on a gallon of gas and still be running in the morning for a few hours.
I use a wood stove for heat in the winter or I have a couple of the old heaters that burn propane.
This has been working well for me for the last 3 years and I'm very happy with the setup.
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Atlincabin
Member
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# Posted: 22 Dec 2018 05:19pm
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Quoting: silverwaterlady I have a question. How does one keep their batteries topped off in a cabin that is not used full time? If you are not there to move the solar panels as the sun changes with the seasons or to brush two feet of snow off the panels how would you be able to leave the battery bank at camp?
We have a small panel (50W if I recall correctly) that is vertical (no snow accumulation) with a charge controller and switch. When we leave the cabin for winter, I just disconnect the main panels & inverter, and switch on the small panel. Keeps the batteries topped up quite well - we always come back to full batteries.
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LastOutlaw
Member
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# Posted: 22 Dec 2018 07:09pm
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I do the same in my cabin. Small solar panel with a charge controller to keep the battery bank topped off.
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moneypitfeeder
Member
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# Posted: 27 Apr 2019 08:53pm
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Hi, not sure where you are at in your cabin mods, but you might want to consider some propane options to reduce your electrical needs. A propane fridge and range/oven work great and might be a good option for you. Our set-up doesn't use any electricity (so no lights when you open the doors) but the work very well. We also use gas lights, but we augment with oil lamps and flashlights. For heat we have a wood stove. We've been able to keep our electrical needs to a very small panel for recharging 2 small deep cycle batteries for pumping water. You might want to spend 1 year "roughing it" to see what your needs really are.
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Aklogcabin
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# Posted: 28 Apr 2019 12:25pm
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I would start small and work up . Good generator. Couple good batteries. I have gone back too many times and redone things, that cost lots f money, because i really didn’t understand my wants. Or needs. As mentioned, it’s a hunting cabin.
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