I need ideas for a solar power shack

[bluedog225]

I’d like a little outbuilding for my solar charge controllers, batteries, and inverters. Keep all the high voltage DC and non-UL listed stuff away from the cabin.

Primary goals are security (anti-theft), the ability to air condition (to keep the batteries happy), and fire-proof.

The $3,500 default option is a 20’ conex. That’s the price to beat.

For security, I’d really like a little tilt up concrete building. Maybe 8’x8’ or so. I feel certain it would be more expensive.

An unusual idea would be to get some heavy metal storage shelves and put two of them back to back. Insulate and cover with corrugated and hang a window unit. Though it would be nice to have something I can walk into and maybe sit on a stool to work on the components.

Other ideas? Has anyone every attempted a tilt up?

 

[kaymccampbell]

Maybe buy a septic tank and put a door in it?

 

[rayra]

extreme heat and cold will be the bane of your batteries. You'll need serious insulation in both regards.

with a little creativity you could readily make a movable form and pour your concrete walls in lifts.
Better yet, use ICF, as you'll want the added insulation anyway. Would be a fun little project.

 

[Firebrick43]

Solid concrete walls with definitely moderate temp swings. You could pour your own walls on the slab and tip up, if only 8x8 I don't know why it would cost more than 3500dollars. Concrete is expensive, but not that expensive.

An 8' tall by 8' long wall 6" thick is going to use 1.2 yards of concrete at 135 dollars a yard. Throw in 40 dollars of #4 rebar should be enough for each wall.

some 2x6x10's for the form, 4 of them at 45-50 dollars per wall, can reuse as rafters.

1200 dollars could have the basic shell of a little concrete building.

 

[nadogail]

With some creative thinking I am confident that you will find ways to economically produce a building within your projected budget.

I have told my clients for years that I offer three options and they can select two of those three options. Nobody gets all three.

The options are Good, FAST and CHEAP.

 

[bluedog225]

I was thinking a pump would be required for 8 feet. And tilt up would be multiple runs. And maybe a hoist to put a concrete roof in place. I may be making it more complicated than it needs to be.

 

[kwb]

Take the septic tank idea and tip it 90degrees. Build one wall with a commercial metal door and frame for access.

1000 gallon 1 piece septic tank | LockwoodPrecast

1000 gallon 1 piece septic tank w/ filter. 5000psi rebar reinforced precast concrete. Approximately 9,500lb. 8'3" x 5'9" x 60" tall w/ lidInlet: 4'1"Outlet: 3'10"

www.lockwoodprecast.com

You still probably will be in this more than a Conex but smaller volume to condition.

 

[jack stand]

There are 8x8 cones boxes also. I think a conex is your best route.
Not hard to insulate on the inside, and fairly simple to disguise as a little building if aesthetics are a factor.
You'll need to cut in some venting. If you have a little slope you could cut the grade and partially bury one end like a walk out basement if you carefully waterproof it (for corrosion purposes) and backfill with a gravel drain just like a house. This would "soften" the look as well.

 

[ludakris04]

I am sure you have probably researched this, but here is a video on a couple that used a shipping container for theirs.

 

[WisJim]

Air conditioning can use lots of energy. How secure does this need to be? I have a good friend who did something similar, not real secure because it is near his home, but all batteries and controls are in an unheated insulated shed in Western Wisconsin where it does get cold in winter and has some really hot days in summer too. He's using lead acid batteries.

 

[Captain Spaulding]

Cell phone companies and others who maintain equipment outdoors use a lot of large NEMA rated enclosures with integrated air-conditioning. While they may not be in your price range, the idea of how they are implemented may work. Lots of doors on both sides so service can be done from the outside. Saves having to triple the size of the space to allow room for a person to have inside access.

 

[bluedog225]

Yeah. A properly insulated, very small container, like the heavy metal shelves, with prop up sides, would be pretty easy to keep cool.

It’s in the country. Where meth heads cut copper out of buildings to sell for scrap. Needs to be hard to enter with a portable grinder. Thinking concrete and lots of welded steel. Enough to require extra batteries. I hate thieves.

 

[theoldwizard1]

Maybe buy a concrete septic tank and put a door in it?

Interesting idea ! You don't want a "traditional" tank because it have two chambers. Get one that has only one chamber. Burying it and running all of the wiring underground will make it kind of "stealthy" !

The biggest issue will be securing the door. Nothing short of a bank vault door can stop an angle grinder and the time/privacy to use it ! Hidden exterior and interior cameras will not stop a break in, but at least you will have evidence.

 

[qdvuu]

If you're considering a concrete septic tank, how about a vault, the kind the telcos use? Designed to be installed underground which may make it easier to reduce the issue with thieves.

The thieves brings up another point about your criteria. If thieves are a big issue, maybe that should be a higher priority than the cost.

 

[dcg9381]

I love the conex idea. I don't think you can beat it for price, construction, water proof, and overall lockable security. I'd probably put IP cameras on it.

Do you have grid power? The one thing issue that I see is the requirement to air-condition - that's a lot of consistent power, especially in Texas... If you're planning on powering that by solar, it's gonna be a problem without a fairly massive array and substantial amount of battery storage.

 

[bluedog225]

All off grid. No external power. The new-ish 48 volt 100 amp hour LiFePO4 server rack batteries are pretty slick. The air conditioner load will be a max of 1000 watts. About 3 panels. And only important during the day to take the edge off. Something to keep it below 85 eff or so.

 

[dcg9381]

All off grid. No external power. The new-ish 48 volt 100 amp hour LiFePO4 server rack batteries are pretty slick. The air conditioner load will be a max of 1000 watts. About 3 panels. And only important during the day to take the edge off. Something to keep it below 85 eff or so.

Yea, we're about to do something with a pretty healthy set of the same batteries.
What HVAC can you run for 1000 watts that's DC powered?

You'll need to foam insulate the conex... Then it's built like a cooler (sorta).
Something still isn't working for me. 3 panels at 300 watts each is ~900 watts, you'll hit peak power for only a few hours (at best) each day.

Your AC pulls 1000 watts (dunno the BTUs). You want to stay below 85 degrees. You're already net negative on power for most of the days in Texas with only 3 panels. Putting the conex in the shade would help.

Remember, you need to easily account for days with partial sun and often 3-day streches where there is no sun at all (overcast). The battery requirements on the DC projects I've done with only minor draws (say 24 watts) - it still takes some substantial batteries to make it go 3-days to a week with out sun... It happens.

 

[bluedog225]

You are correct. I’ve got 60+ panels. Only a small portion will go towards the air con during the day.

The general stuff I’ve seen indicated that 1000 watts is a conservative estimate for a single head mini split. Will have an inverter. Though there is a DC direct out there.

What I really want is an inverter dual hose portable.

 

[rayra]

Interesting idea ! You don't want a "traditional" tank because it have two chambers. Get one that has only one chamber. Burying it and running all of the wiring underground will make it kind of "stealthy" !

The biggest issue will be securing the door. Nothing short of a bank vault door can stop an angle grinder and the time/privacy to use it ! Hidden exterior and interior cameras will not stop a break in, but at least you will have evidence.

sticking it in the ground would also go a long way towards moderating temperature extremes, too.

Bury it with the panels overhead above ground and you also hide and limit access to the structure. Place it so the equipment vault is shaded by the panels in summer.

Throw some 'junk' on top of the vault, let the weeds / grass grow tall around the edges, it will just look like a junk pile.

 

[bluedog225]

A buried electrical vault for the batteries, inverter, and charge controller would solve the temperature issue. A real man cave. But possible flooding, humidity control, and access issues have stopped me.

 

[LB-1911]

A buried electrical vault for the batteries, inverter, and charge controller would solve the temperature issue. A real man cave. But possible flooding, humidity control, and access issues have stopped me.

Have you considered a surplus commo shelter?
One example @

Shelter, Communications

You won't believe this military surplus shelter we found! This insulated secure aluminum room is great for storage camping, storm shelters and much more!

colemans.com

 

[ipgenie]

Burry it so the top is 1' above grade, set a little bully barn shed on it and slope the ground down to grade. Should keep it dry and hide the access hatch in the shed floor.

Meth heads might break in and steal what's in the shed but won't know the expensive stuff is hidden.