Where to Store Solar Components and Batteries in Cold Climates

[MaineHomesteader]

Hey All,

We’re still in the planning phases of our solar system but one of our big concerns is storage. We are located in central Maine.

We are building a 20x36 two story house that will be fully off grid. It will be a slab foundation so we won’t have basement storage space and we will not have an attached garage. We don’t really want to have the solar equipment in the house, especially batteries as it’s a rather small space and everything is going to take quite a bit of room.

Could we build a small shed for the components and batteries? I am not sure if we are going with lithium or lead acid batteries yet. Obviously my biggest concern is freezing temperatures. If we super insulated a small shed would the components themselves generate enough heat to keep temps above freezing? I don’t want to have to run a propane heater as that kind of defeats the purpose of being off grid.

I tried to find some similar information on this forum but didn’t really see much pertaining to this in cold climates so any feedback would be greatly appreciated!

 

[740GLE]

4 seasons? Or 3 seasons?

Camp or permanent residence?

 

[Steve_S]

The cold will have no effect as such on stored parts. Batteries of course could be an issue depending on chemistry. Please appreciate that Lead Acid battery quality has significantly dropped over the years and you will likely not get more than 5 years out of your first bank and when you couple that with the monthly maintenance, watering etc, you will want to change over when they die. But then you'll be pissed at tossing out a few grand worth of Dead Lead. Buy ONCE and don't turn back. LFP/Lithium Iron Phosphate is the only way to go really, especially if you are "Penny & Dollar Wise". LFP can discharge up to -20C/-4F Temp but cannot be charged below 0C/32F.

Many of us do actually build a "Power House" to house the solar gear because the fans in the Inverters & Solar Controllers etc can get quiet loud and terribly annoying.

My Powerhouse (8'x16') as an example and I am further north than you !
Frost Protected Slab foundation with R20 HD Foam under it and up the sides.
- Slab also has Radiant Pex within (single zone - simple) to provide for passive Solar Heating.
I do have a small RV Propane Furnace in there and it is set to keep the structure at 15C/59F
NB: Guaranteed temp is required as this is also my Pumphouse and has my 50 Gallon pressure tank in there.
Walls are Thermally broken: 2x4 structure with 4" of foam between studs, 1" HD Foam between studs & sheathing, 2" airspace between sheathing & cedar siding.
Roof is a Cool Roof system: Thermally broken like the walls but also with a Ridge Vent for passive airflow cooling using convection.

This ensures that the building does not gain heat in summer and it never gets over 27C/80F when it is 40C/104F outside, this is similar to my house which is a passive hyper efficient design.

Couple of tips:
Use a SOFT-START Well Pump !
I use a Grundfos SQ-5, 120VAC Softstart deep well pump 280' deep. It starts at 500W and steps up to 1200W by the time it reaches 52PSI cutoff. You never notice a pressure change and works a wonder on solar inverter. 280' deep to 50 Gal pressure tank then 75' to house underground.

Make use of Passive Technologies to save a LARGE Amount of heating/cooling. Thermally broken walls can keep a home 25% cooler without any extra effort by preventing heat/cool to transfer through the walls. A Cool Roof System with a thermally broken roof that uses convention to vent warmed air out during summer & preventing cold transfer through the roof can save you over 50% of your heating/cooling energy.

Hot Summer day @ 40C/104F, my home does NOT go above 27C/80F inside and I have NO AC ! Gave it away...
In winter on a -30C/-22F day, I keep my house @ 25C/77F and my radiant heat runs for 4 hours in a 24 hour period to maintain that heat.
Yes, the house has an FPSF Slab with Radiant Heat, house has 9" thick walls with solid foam between studs and thermally broken, roof has 8" of PolyISO between rafters + 1" thermal shield + 2" airspace (proper cool roof).

Hope to helps, Good Luck.

 

[wpns]

Yeah, go with EG4 18Kpv and some number of EG4 Wallmount PowerPro batteries, all of which are rated for outdoor use. Then (belt and suspenders) build a shed around them to protect them from the worst of the elements. I wouldn’t worry about supplemental heating, the inverters will be fine, and the batteries have built-in heaters.

 

[MaineHomesteader]

4 seasons? Or 3 seasons?

Camp or permanent residence?

4 season and permanent residence.

 

[再生可能 エネルギー]

Many of us do actually build a "Power House" to house the solar gear because the fans in the Inverters and
Solar Controllers etc can get quiet loud and terribly annoying. My Powerhouse (8'x16') as an example...

Make use of Passive Technologies to save a LARGE Amount of heating/cooling.
Thermally broken walls can keep a home 25% cooler without any extra effort by preventing heat/cool to transfer through the walls.

A Cool Roof System with a thermally broken roof that uses convention to vent warmed air out during summer and
preventing cold transfer through the roof can save you over 50% of your heating/cooling energy.

Hot Summer day @ 40C/104F, my home does NOT go above 27C/80F inside and I have NO AC ! Gave it away...
In winter on a -30C/-22F day, I keep my house @ 25C/77F and my radiant heat runs for 4 hours in a 24 hour period to maintain that heat.

Yes, the house has an FPSF Slab with Radiant Heat, house has 9" thick walls with solid foam between studs and thermally broken,
roof has 8" of PolyISO between rafters + 1" thermal shield + 2" airspace (proper cool roof).

I wonder if building a mini shed underground to store the batteries at a constant and not freezing temperature,
would be almost as simple and even less costly to build and then to keep warm, if digging was a possible option?

I don't know how deep this would be needed, but I believe that telephone companies use this kind of solution.
Some of the issues might be that the foundation slab must stay elevated above the groundwater table,
ventilation to prevent condensation would be necessary, and the access would be more difficult than above ground.

About the construction, in some areas people use pre-fabricated septic tanks, so could such type of container
could be simple to use than making a whole underground shed?

 

[740GLE]

You can’t beat Steve’s advice he’s spot on. You can’t over insulate, especially from the ground/slab perspective. The best BTU used is the one you never lose.

What will be your primary source of heat?

 

[再生可能 エネルギー]

You can’t beat Steve’s advice he’s spot on. You can’t over insulate, especially from the ground/slab perspective.
The best BTU used is the one you never lose.

What will be your primary source of heat?

If you also keep your inverters underground, would a 5 to 10% energy losses providing enough heat?

 

[MaineHomesteader]

You can’t beat Steve’s advice he’s spot on. You can’t over insulate, especially from the ground/slab perspective. The best BTU used is the one you never lose.

What will be your primary source of heat?

I would like to not have a heat source in the “Power house.” For our own house it will be a wood stove.

 

[Steve_S]

You can’t beat Steve’s advice he’s spot on. You can’t over insulate, especially from the ground/slab perspective. The best BTU used is the one you never lose.

What will be your primary source of heat?

In my case because both my Powerhouse & my House are on FPSF Slabs that thermal mass makes a perfect heat retention & distribution systems over winter. In the summertime the slabs average 18C/64F +/- 1C and regulate the temps keeping the inside structure cooler. By using thermally broken walls & roof with passive ventilation provided by natural convection, you essentially isolate the structures from losing/gaining heat or cold depending on season.

A lot more people up here in North Country are avoiding basements and so many are doing slabs with radiant heating. Now with heatpumps that can supply your hot water & radiant heating needs it just makes sense. BTW: I'm a crusty geezer with a lot of aches & pains and I'll tell ya, there is nothing like having a warm floor to step out on, or a warm bed because everything, walls & all is the same temp +/- a couple of degrees. Step out of the shower onto a warm floor (even ceramic tile!).

I did a DIY Radiant Heating system and used a designed kit from here and I Very Highly Recommend them, they are in Vermont.

DIY Radiant Floor Heating | DIY Radiant Heat | Radiant Company

We offer free help designing a radiant floor heat system to fit your needs. If you’ve received shockingly high quotes for radiant floor heating and are still recovering….relief is right here.

www.radiantcompany.com

 

[nc73]

I installed mine in a closet under the stairs. No worries about equipment getting stolen or batteries freezing.

 

[Supervstech]

Hey All,

We’re still in the planning phases of our solar system but one of our big concerns is storage. We are located in central Maine.

We are building a 20x36 two story house that will be fully off grid. It will be a slab foundation so we won’t have basement storage space and we will not have an attached garage. We don’t really want to have the solar equipment in the house, especially batteries as it’s a rather small space and everything is going to take quite a bit of room.

Could we build a small shed for the components and batteries? I am not sure if we are going with lithium or lead acid batteries yet. Obviously my biggest concern is freezing temperatures. If we super insulated a small shed would the components themselves generate enough heat to keep temps above freezing? I don’t want to have to run a propane heater as that kind of defeats the purpose of being off grid.

I tried to find some similar information on this forum but didn’t really see much pertaining to this in cold climates so any feedback would be greatly appreciated!

How difficult would it be to add a basement to the build?

 

[nc73]

How difficult would it be to add a basement to the build?

Closets are cheaper

 

[Steve_S]

How difficult would it be to add a basement to the build?

Difficulty is ONE thing.... the extra 15-20K to dig the hole, prep & pour (small & simple) counts too.

 

[740GLE]

How difficult would it be to add a basement to the build?

Instead of a full basement there is such thing a a “frost wall”, think of it as a crawl space 3’ or so. If you were to put solar components in there you’d be back to conditioning the environment, moisture is your enemy, at that point it’d prob cheaper to go shed route.

It’s still a chunk of change over a slab, but way cheaper than a full basement. There’s a reason why slabs aren’t common place in Maine.

 

[Supervstech]

Instead of a full basement there is such thing a a “frost wall”, think of it as a crawl space 3’ or so. If you were to put solar components in there you’d be back to conditioning the environment, moisture is your enemy, at that point it’d prob cheaper to go shed route.

It’s still a chunk of change over a slab, but way cheaper than a full basement. There’s a reason why slabs aren’t common place in Maine.

Or maybe a root cellar small underground room off the slab?

 

[wpns]

Don’t dig a foxhole just for your solar stuff, it’s probably less expensive to add a utility room. Put it in a leanto attached to the house. At least that won’t flood.

 

[peakbagger]

It's worth reviewing this old video clip and the attached PDFs on how frost and frost heaves work in Maine. Dick Hill passed away but its still the best practical advice on deal with cold temps. Its counterintuitive to most that slab insulation is intended to keep heat in the ground to keep it from freezing. http://www.hotandcold.tv/frost_heaves.html

 

[green mountain boys]

If digging conditions allow, I would go underground. A root cellar type of structure. Use the ground to moderate the temperature. The cold can get really nasty in northern New England. Remember the winters of 1992-93 and 1976-77 or was it 1977-78?

 

[Supervstech]

If digging conditions allow, I would go underground. A root cellar type of structure. Use the ground to moderate the temperature. The cold can get really nasty in northern New England. Remember the winters of 1992-93 and 1976-77 or was it 1977-78?

Weren't those winters cold due to volcanoc activity?