Pole Barn Solution Suitable for Cold Weather (MN)

[tbarkermn]

Total newb here, 1st post. Been watching tons of great solar content on You Tube from awesome folks like Will . That said, I'm getting a little overwhelmed by all the options and details. I'm looking for an economical yet practical solar solution for my off-grid pole barn in central MN. One of the areas I'm struggling with is how to deal with the cold and batteries. The pole shed is not heated or insulated and currently has no power connected. And in MN it gets really really cold and solar in winter is a bit limiting. Some details about what I'm hoping to accomplish -

1) I'd like to have enough power to add some LED lighting to the building for occasional use. The building is large, 40x60x14, so I figure I'll need quite a few lights. Just for giggles if I find a 20W light and get 20 of them, that's ~400 watts. Lighting is my primary objective at the moment (but don't want to totally limit myself down the road
2) would be nice to be able to plug in a power tool from time to time
3) Possible a garage door opener....

Worth noting, this is on a property that I visit about once a week so my power needs are pretty dispersed. At most a few hours a week.

I'm looking for some advice and size of system and also what battery chemistry and setup would be best for very cold environment. I'm assuming I'll need to heat the batteries somehow which will require power as well. I also realize that LED lighting may not work so great when it gets sub-zero but I'll just have to deal with that I suppose.

Appreciate thoughts, suggestions.

 

[Supervstech]

Does the building have a cellar? Can you get one installed? Like a service pit or something?
A 8’deep cellar with a door should keep batteries warm enough.
Otherwise, you are going to need lead acid, and be ABSOLUTELY certain they stay above 80% charge in winter…

 

[tbarkermn]

Does the building have a cellar? Can you get one installed? Like a service pit or something?
A 8’deep cellar with a door should keep batteries warm enough.
Otherwise, you are going to need lead acid, and be ABSOLUTELY certain they stay above 80% charge in winter…

No cellar. Not really an option either. Water table too high.

 

[WYtreasure]

No cellar. Not really an option either. Water table too high.

Welcome to the party tbarker.

As an alternative to a normal cellar perhaps a water tank, to keep the water out, would work if you could keep it from floating.

 

[ErikOlson]

Could build a small, highly insulated, mechanical room. Put batteries and inverter in there, along with a small heater.

Or even a small super insulated battery box, with thermostat controlled heater. Might want a small gen as backup to prevent discharge of the batteries.

 

[Wellbuilt]

I think if you built a box with 2” foam board all around they will stay 45o or so with regular charging .
I have a power vent allso .
My battery’s can start off at 10o and in a few days they are up to 45o or so .

 

[tbarkermn]

I think if you built a box with 2” foam board all around they will stay 45o or so with regular charging .
I have a power vent allso .
My battery’s can start off at 10o and in a few days they are up to 45o or so .
View attachment 81438

This is an interesting idea and something I've been considering. May I ask how cold it gets where you have these installed? I'm guessing in addition to something like this I'd need to add some type of electrical heat.....

 

[Samsonite801]

This is an interesting idea and something I've been considering. May I ask how cold it gets where you have these installed? I'm guessing in addition to something like this I'd need to add some type of electrical heat.....

Yeah and search around here for the heat pad threads as well. Using a box like Wellbuilt used in conjunction with heater pads or heater blankets should be fairly effective for a low wattage requirement, and holding it inside the localized area of the box/container, since it is insulated.

 

[Wellbuilt]

It’s been 0 to -21 for the last 3 weeks
the battery’s where 10o when I got up there and after 4 days of charging /discharging they where 45o 47o
I have a 2” vent fan drawing gas’s from the box or it would be warmer .
I would just use golf cart battery’s and box them up .
As long as they are charged they can see -70 % with out freezing ?
No need to add heat .

 

[tbarkermn]

After bit more research I learned about self heating lithium batteries from renogy, battle born, and canbat as examples. I'm thinking the battle born self heating batteries in an insulated box might be a decent option. I'm leaning towards the battle born because it appears they will heat themselves from battery power with minimal draw according to website vs. requiring external source like some of the other options. The reason I like the battle born approach is they'll still stay warm at night when no solar is coming in to keep heated. Presumably, the solar will top them back off in the daytime. Kind of pricey though. Just thought I'd mention this option on this thread in case others are interested or have some first hand experience with this approach worth sharing.

 

[Prefersdirt]

Cover the box holding the batteries with bales of straw for added insulation.

Do a DIY geothermal if you want a warm room. Low power requirements. ESP if you just ran the plumbing under the battery box. Temp dependent pump switch

 

[streetrodder2]

tbarker,

I have a similar issue to you. I just built a 42 x 48 x 12 pole building in Minnesota that is 400' from a power source thru the woods. I was ready to buy a small solar system to just power some lights. I was going to use a 12v marine battery until I researched the cold batterry issue. I use this building to store my snowmobiles in the winter so I will need the lighting in the winter when it gets to -35F. I was wondering what you decided to do. Did you buy the expensive Battle Born battery or did you come up with some kind of insulated box with a temerature controlled pad heater that will not disipate the battery power on the short cold cloudy Minnesota winter days.

I am thinking that solar may not be the best solution. I may invest in a proper power line conected to the grid.

Someone talk me back into how I can use solar!

 

[tbarkermn]

tbarker,

I have a similar issue to you. I just built a 42 x 48 x 12 pole building in Minnesota that is 400' from a power source thru the woods. I was ready to buy a small solar system to just power some lights. I was going to use a 12v marine battery until I researched the cold batterry issue. I use this building to store my snowmobiles in the winter so I will need the lighting in the winter when it gets to -35F. I was wondering what you decided to do. Did you buy the expensive Battle Born battery or did you come up with some kind of insulated box with a temerature controlled pad heater that will not disipate the battery power on the short cold cloudy Minnesota winter days.

I am thinking that solar may not be the best solution. I may invest in a proper power line conected to the grid.

Someone talk me back into how I can use solar!

I haven't been able to justify the costs and hassle for solar solution at this time. My current plan is to wire up a few LED UFO lights (these are crazy bright - might want to look into them if you haven't already) and utilize the Honda generator I already own as power source. I'll install a power inlet for energizing the lights circuit and just fire up the generator when I'm on site. I'm still considering, researching solar, and the tech keeps advancing. I'll probably slowly step into a solar solution over time.

 

[streetrodder2]

Thanks for your reply. Thats a interesting solution. I have been thinking about purchasing a generator as well. I do have a Honda snowblower that starts pretty easy when its cold so that might work. Just not as convieniant as fliping a switch or having a motion activated light come on when I aproach the shed.

 

[tbarkermn]

Thanks for your reply. Thats a interesting solution. I have been thinking about purchasing a generator as well. I do have a Honda snowblower that starts pretty easy when its cold so that might work. Just not as convieniant as fliping a switch or having a motion activated light come on when I aproach the shed.

You can purchase solar powered lights from amazon that are pretty nice. I'm planning to purchase one or two of these. You just mount them to surface and they're ready to go. This way you have some motion activated lighting when you pull up to your building. For me, since I already own the generator, which can come in handy for lots of things, that solutions seems to be the most practical and cost effective at this time. Might be good option for you as well. My generator is the 2200 watt version. For my building I'm thinking of getting 8 of the UFO lights to hang from the ceiling and put 4 on 1 switch and 4 on another switch that way I can manage wattage I'm using more effectively and only light whichever area I'm working in.

 

[Wellbuilt]

There is no issue with lead acid batteries and cold weather .
If they are charging and dis charging they make there own heat , mine stay around 45o all winter ?
deep cycle marine batteries aren’t really deep cycle
use2 6 V golf cart batteries from Sam’s Club or Costco they hold up .
Put them in a insulated box . 300watt morningStar inverter
small Charge controller and 600 watts of panels
it puts out more then 300 watts

 

[WYtreasure]

You can purchase solar powered lights from amazon that are pretty nice. I'm planning to purchase one or two of these. You just mount them to surface and they're ready to go. This way you have some motion activated lighting when you pull up to your building. For me, since I already own the generator, which can come in handy for lots of things, that solutions seems to be the most practical and cost effective at this time. Might be good option for you as well. My generator is the 2200 watt version. For my building I'm thinking of getting 8 of the UFO lights to hang from the ceiling and put 4 on 1 switch and 4 on another switch that way I can manage wattage I'm using more effectively and only light whichever area I'm working in.

The solar powered lights have a battery(s) in them. You might want to do some homework to see if they will wake up when it's chilly. Some of the 120 volt LED fixtures don't like to work when it gets cold here in Wyoming. Some of my LED fixtures are 10 years old though.

 

[kampto]

I have a shed and barn with stand alone systems, air temp inside gets to low 20's in winter. Running combined 24V Lead acid battery's, Victron MPPT 75/15 CC, and a panel or 2 off craigslist. Running 12V DC light bulbs from Amazon. Using a $25 24V to 12V buck converter. No issues for years.

 

[WYtreasure]

I have a shed and barn with stand alone systems, air temp inside gets to low 20's in winter. Running combined 24V Lead acid battery's, Victron MPPT 75/15 CC, and a panel or 2 off craigslist. Running 12V DC light bulbs from Amazon. Using a $25 24V to 12V buck converter. No issues for years.

Sounds like one of those "works good, lasts long time" setups. It's nice to hear from folks who can make "simple" actually work well.

 

[Geokilroy]

I think if you built a box with 2” foam board all around they will stay 45o or so with regular charging .
I have a power vent allso .
My battery’s can start off at 10o and in a few days they are up to 45o or so .
View attachment 81438

Great looking box. Should hold the temp quite well.
I DIY'ed a 280ah battery, with parts ordered from Amy at Docan. They shipped from Texas warehouse and arrived in just over a week. It took me a couple days to do the build because it was my first build. Works great and cost about $800 for 280ah. And my BMS has cold temp shutoff. Adding heaters would only cost about another $100. Check the posted threads about heaters to find out what everyone is using.
200 or 300 wats in panels should keep your batteries charged even with the heaters running during the winter/low sun days up north. I believe these heaters only draw 30 to 40 watts. I would also look into a thermostat system to only come on when actually needed. You would be supplying this power directly from PV during the day and drawing from the batteries after the sun goes down. With a nice battery box as above it should limit how long or often the heaters need to come on.
Remember: Lead/AGM batteries should only be drawn down to 50%, but LiFePO4 can be drawn down to 20% remaining and not do major damage. And LiFePo4 can charge much faster than Lead/AGM.
For less than $1000 to get 280ah (about 250ah useable) with low temp cutoff and heat. If I can build mine, you can build one also.