Solar Shed Summary: My Off Grid Office

A few months ago I moved to a few acres in the country, and needed somewhere to work - so I built myself a solar powered off grid office out of a Tuff-Shed Pro Studio!


This is a companion discussion topic for the original entry at https://www.sevarg.net/2016/07/31/solar-shed-summary-my-off-grid-office/

(Comments from Blogger)

2016-07-30 by Unknown

The fire extinguisher is actually big enough to be useful although dry powder will make a huge mess and potentially ruin any electronics it get’s into. I’d also suggest hanging a set of cable cutters on the shed near the battery box in case you need to cut off power in an expedient manner and your switches/fuses are inadequate.


2016-07-31 by Russell Graves

The primary goal with that is to save the structure - I recognize that it will make a big mess and I’ll have to replace a lot of bench electronics. Do you have a suggestion for where I could find something that wouldn’t make as much of a mess?

I hadn’t thought about cable cutters but that’s a really good idea for the north wall. The interconnect loops do lend themselves to being emergency cutoffs.


2016-07-31 by Mike Halcrow

From the battery spec sheet:

"As a rule of thumb, for every 10°C increase in temperature the reaction rate doubles. Thus, a month of operation at 35°C is equivalent in battery life to two months at 25°C. Heat is an enemy of all lead acid batteries, FLA, AGM and gel alike and even small increases in temperature will have a major influence on battery life."

What’s your expected battery life given that it’s 37C outside?


2016-08-01 by Russell Graves

Shorter than if it were cooler.

I rarely see more than 30-32C on the batteries - the thermal mass of lead acid combined with being on the shaded north side helps a lot. I am working on plans to push some conditioned air into the battery box to help cool them in the summer and heat them in the winter, but I haven’t gotten that finished yet.


2016-08-01 by J-Lao

This is one of the cooler things I’ve seen all year, and I see a lot of cool stuff. Nice work!


2016-08-01 by Michael Stephenson

I’d imagine he’s suggesting a CO2 fire extinguisher.


2016-08-01 by Anonymous

Replace that fire extinguisher with a halon one like this and you won’t ruin all your electronics in a fire:
http://www.webstaurantstore.com/buckeye-5-lb-halotron-fire-extinguisher-75550-ul-rated-5b-c-rechargeable-untagged/47275550.html?utm_source=Google&utm_medium=cpc&utm_campaign=GoogleShopping&gclid=CLOC14e7oM4CFUNZhgodGU8Iuw


2016-08-01 by Jamie

Looks great! the only thing I would of done different is put the rigid foam behind the siding but I live somewhere that gets way below freezing in the winter.


2016-08-01 by Unknown

How did you get internet access out there since I assume you didn’t trench in fiber :slight_smile:


2016-08-01 by Russell Graves

Thanks for the suggestion - I’ll look into something like that.


2016-08-01 by Russell Graves

Wireless bridge to the house. I’ve got a pair of Mikrotik Lite2 units up for now.


2016-08-01 by Iteration_X

What was your total investment? Do you have an expense break down?


2016-08-01 by Russell Graves

It’s in the $15k-$17k range - I don’t have a full breakdown yet.


2016-08-01 by Fred Eaker

Did the structure require and state/local inspection?


2016-08-01 by Russell Graves

No - it’s below the 200 sq ft minimum for permits/inspections.


2016-08-01 by Unknown

Hey - thanks for taking the time to document the build and share it. Happy shedding!


2016-08-01 by Iteration_X

Thank you. I see now that you already had that in your post. Sorry. (reading… it works)


2016-08-01 by Gary

VERY nice work. The off-grid part is awesome! It’s so nice, you might want to dress it up a little by making nicer shelves. Perhaps adjustable shelves or build in some wall-to-wall shelving for a cleaner look. Perhaps a cabinet to store some of the messy things? I am both inspired and jealous.


2016-08-01 by overflow

Great build and thanks for documenting it. You may want to vent your battery box some near the top to prevent build-up of hydrogen gas.


2016-08-01 by Unknown

Since you have excess energy available you could run a small vent into the battery box to reduce temp to help increase battery life.


2016-08-01 by Unknown

CO2 isn’t meant to be used on wood or textiles IIRC, which would be an issue.


2016-08-01 by Unknown

Great Article , thank you for taking the time to write it up and document, I imagine it will help a lot of people over time. Lots of great Ideas there. I want to live off-Grid One day, Oh, I notice how well you insulated the place. cool, Actually make sure you leave a window cracked if you heat with Kerosene, Propane, etc. - Get a C=O=C detector maybe. Thanks again!!


2016-08-01 by ddd228

I have an 8X12 Tuffshed. Solar power,but only 300W. max.1,500 pure sign wave go Power inverter.(3)31M AGM’s.Shed pulls around 220W all in.One more panel on it’s way.http://i514.photobucket.com/albums/t345/ddd228/temporary_zpssmyoamgd.jpg~original
http://i514.photobucket.com/albums/t345/ddd228/temporary_zpsinqu6qgx.jpg~original
I made a wind turbine,but took it down. Solar is WAY better.
Dave in Seattle.


2016-08-01 by Russell Graves

Off-grid power systems refer to not having mains power available from the power grid.

Apparently, everyone else thinks off-grid means something else. It’s a quite interconnected office, since I work online. So, I use off-grid my way. I really didn’t expect so many people to get bent out of shape about my use of off-grid for a solar power system.


2016-08-01 by Voodoo

" I’d prefer a metal roof, but for a 40% discount I can overlook a few things." Highly recommend investing in a white or aluminium roof. You can put a split seem right over the top of that one - just insure you leave an air gap. But you knew that ;0) Awesome job!


2016-08-01 by Spocko

Suggestion on the Fire Extinguisher. 10 lb CO2. Will work for the electrical fires you are afraid of and won’t make a mess like dry chemical. Don’t get a Halon one. Halon was phased out in 1994 because it destroyed the Ozone layer.
Some extinguishers might still be available, but if you use it getting it recharged is almost impossible.
Also, if you buy a CO2 fire extinguisher make sure that it has been tested by a licensed NAFED dealer. The containers need to be hydrotested every 10 years. (The date of the last test is usually stamped on the cylinder like they do with Scuba tanks.)
(Source- used to work in the industry filling and testing CO2 fire extinguishers. )


2016-08-01 by Fortes Fortuna Juvat

Is there enough power generation and storage to work through an 7-8 hour night?


2016-08-01 by Russell Graves

Possibly. I didn’t design it for that, though. As long as you kept it below about 500W sustained use, it’d be fine with this pack.


2016-08-01 by Virg

I was going to suggest to dig down a couple feet and place the tub there, but then remembered the rock.

The other approach would be to just have a “roof” for the batteries with no walls around them for added ventilation. If security is a concern, you can probably surround them with chain link fencing.


2016-08-01 by Unknown

Halotron is a good option to protect your electronics. They don’t leave the residue that dry chemical extinguishers like the one it looks like you have there will put out. As was mentioned, dry chemical extinguishers will probably ruin electronics, but Halotron should keep them from getting damaged further by the extinguishing agent. Here is a link to their website if you’re interested: Halotron — Halotron I


2016-08-01 by Withheld

Fantastic build, what exactly do you do in terms of work if I may ask?

People think off-grid as in living somewhere in the salt flats or something. It’s neat that you can technically just move this shed somewhere else and it’ll still work (granted, you’d use satellite internet).

You seem to have done your homework on most of the installation process/solar panel setup/etc. You say you remade a few batteries, for some reason I just get the vibe that you’re an electrical engineer or sorts, am I close?


2016-08-01 by Russell Graves

I do a range of things - generic tech work/web backend stuff, sysadmin, battery pack rebuilds (look around my blog for examples of this). I’ve been attempting to make a bit on blogging as well, with device teardowns and analysis.


2016-08-01 by Anonymous

Very nice build! A little off topic but I couldn’t help but wonder what kind of internet connection are you getting out in that rural environment?


2016-08-01 by Phil

You could vent some excess air con into the battery box ?


2016-08-01 by Unknown

I would suggest an Ansul clean guard fire extinguisher such as this one. http://www.safetyemporium.com/09626 The Halon ones have been phased out in most places. The clan guard ones are what I see day to day in data centers as they are mostly harmless to sensitive electronics.


2016-08-01 by Russell Graves

Phil - yes, I plan to do that eventually.


2016-08-01 by Russell Graves

Rural wifi. 15/2 for $100/mo. It works.


2016-08-01 by Peter C. Thompson

You can still buy Halon, which is MUCH less toxic than the newer “alternates”. You can buy it from racing car stores.

Also, check into www.discountfuse.com for some really good DC fuses (I’ve built my own electric car and that needs SERIOUS fuses).


2016-08-01 by Unknown

I would have assumed you were outside of any permits/inspections period since you said you were rural.


2016-08-01 by Peter C. Thompson

I was reading about a guy that used to live down in the coastal mountains of Mexico. He was off-grid, yet he had broadband connection to his house. I agree with Russell that “off-grid” means you are not connected to the power grid.


2016-08-01 by Klaus Larsen

Nice job. You may want to consider some sort of flashing around the hole you cut for the ac; you don’t want water or moisture sneaking into the walls from the outside. Cheers.


2016-08-01 by Adam Reynolds

I’m curious why you didn’t off-grid the house and run a cable up to the shoffice. You could still do this given the setup. I can see having a reliable power supply in mid-winter to be key to use.

One thing I did when I built my shoffice was to install a tiny wood burner (with ventilation + monoxide detector). It removed the biggest power expense.


2016-08-02 by Unknown

If you are going to go with a HALON extinguisher system… Please, please please please, put the trigger for it OUTSIDE of the shed. make sure you (and any other living thing) are outside, and the door is SHUT, when you fire it.

I used to work for a chemical and hazmat recycler, and they had halon extinguisher systems in the boxes of the trucks. One guy was sweeping out his 15’ box and somehow triggered his. Even with the roll up door wide open, he died before he could exit. They are no joke.


2016-08-02 by Unknown

A hole saw, some laundry vents, and some laundry vent hosing should do the trick well enough.


2016-08-02 by Unknown

Call the local fire department they will do a check and suggest a appropriate fire extinguisher for your building/electronics etc.


2016-08-02 by Unknown

Side note about your normal fire extinguisher. While it will make a mess if there is no power to the electronics when it goes off it will not damage them you will just need a vacuum to clean them out.

Personal Experience. My two cents is make a master breaker/fuse to your battery back and the intraoffice. flip the breaker to kill the power to all electronics. Then fire the extinguisher.


2016-08-02 by Karah and Doug Pope

Great project. You might consider solar thermal panels for heat. Easy diy project, very efficient


2016-08-03 by Clayton

This is a fantastic idea. Love it. Good inspiration for me to consider as my house can feel a bit tight with a dedicated office.

I don’t quite have the solar/electronic chops as you, but in my situation it would not be difficult to run a dedicated line to the shed and possibly fab in solar later as I learn more.


2016-08-03 by Russell Graves

Basalt. The problems with trenching through it.


2016-08-03 by Russell Graves

If you can run a dedicated line, do that. It’ll be cheaper and less of a pain to deal with. My system is fine, but I do have to pay attention to energy.


2016-08-03 by Russell Graves

John - I already have a 2" PVC conduit going into the battery box with nothing in it (intended for airflow). I just need to get an intake on my office before I set up exhaust from it…


2016-08-03 by Russell Graves

Sadly, “rural” does not mean “outside of any permits/inspections.” I wish it did…


2016-08-03 by Russell Graves

Gary -

I don’t see myself adjusting shelving any time in the future, so static shelves are fine. There’s just not that much vertical space in there. I’ve been using parts holders to store small stuff, though I’m already out of space…


2016-08-03 by Russell Graves

I could, but I’m not sure what I’d gain. My house has a metal roof for fire resistance reasons, but I’m not that concerned about my office. I mow around it. As far as thermal demand go, I can keep it at 70F inside when it’s over 100F out, so it’s not a problem.


2016-08-15 by Unknown

My brother in-law and I built a finished out shed for me to use as an (on-grid) office, he suggested adding a radiant barrier on the ceiling before sheetrock because there was no attic space. We also insulated under the floor. Installed 2 windows for those days were no AC or heater was needed. The one thing that I did not anticipate was the noise from the air conditioner while on meetings, I might have been able to hear ok but people on the other end complained about background noise. I ended up having to turn it off for phone calls, which got hot sometimes. Worked remotely in the shed for 2 years before changing jobs. It was great and my wife and kids knew if I was in the shed I was “at work”.


2016-08-15 by Mr Bobby

If you wanted it to be mobile you could roof mount the solar panels and put the whole thing on some kind of trailer. (Assuming you could figure out some sort of leveling/stabilizing jacks.) Not sure exactly why you’d want to do that but it seemed like the natural next step with not being tethered to power.


2016-08-15 by Russell Graves

Sounds similar - very cool! Yes, the AC noise can be a problem for phone calls.


2016-08-23 by Unknown

Interesting build. IMHO, for the money spent you’d have been much better off to use a quality mini-split unit for HVAC. Way, way more efficient - as much as 22 SEER or better - and much quieter. I’ve owned one of those Frigidaire units and hope your experience is not like mine, otherwise you’re going to be sorry you cut a hole in a perfectly good wall and glued that POS in there.


2016-08-24 by Unknown

Came here via a Brent Ozar link and it was really great seeing your man cave built in stages. Would love to do this myself but living in the UK, we don’t get much sun! ;o) Thanks for sharing, what a brilliant office set up.


2016-08-24 by Russell Graves

Fortunately, if I need to replace it, I can swap it out quickly. :slight_smile:

I’ll see. I couldn’t find a mini split that was suited to my size of office or installation ability.


2016-08-24 by Russell Graves

Yes, but I don’t believe most of the ground in the UK is filled with large rocks. Just trench power if you can.


2016-08-27 by Tom

You also need to consider the size of venting for the hydrogen gas released during charging. There are minimum vent area calculators available online.


2016-08-27 by ducksauz

If you’re working with LiPo and LiIon batteries, in theory what you want is a class D fire extinguisher. The dry chemical will make a mess, but it will be melted by the heat of the battery fire and then (theoretically) starve it of oxygen. However, having been to an extinguisher training at a local FD where we used one to extinguish a LiPo pack that we punctured to set it off, it didn’t do a great job. There’s a lot of energy in them thar chemicals, and once the reaction gets going, it really wants to just burn itself out.

Long story short, if you ever have a LiPo pack flame up on you on the bench, just get out of the space and let it burn out. The fume are really bad for you. Call 911 and keep an eye on it from the doorway. Stuff is replaceable, your life and health are not.


2016-08-28 by JD

If you need some air exchange look into an HRV or ERV depending on your climate. They will give you fresh air while recovering ~70% of the energy you spent for your cool or warm indoor air.


2016-08-29 by Unknown

Hi Russell,
I like the end product. Have you considered at any point using the shipping containers turned houses/workshops? I’m quite sure that one (used) with a prebuilt isolation could be found for under 10k$.


2016-09-01 by Ned Funnell

I really like this project and the way it turned out. My wife and I will be shopping for a house over the next year and we’re going to keep a office shed like this in mind as a possibility in case we like a house with just not quite enough space. The ability to isolate work space from living space might be enough reason to undertake such a project on its own. I am a bit surprised that the cost was about $10k excluding solar. What were the top costs in that area?


2016-09-01 by Ned Funnell

Russell, did you consider burning wood for winter heat? A wood burning stove would take up a lot of space, though.


2016-09-01 by Russell Graves

I considered it, and I have literally no free space in here. I might be able to put in a little ammo box stove or something, but there’s still no good spot for it.


2016-09-01 by Russell Graves

Insulation, plywood, and screws are expensive. Plus the interior finishing work I’ve done with shelving/storage boxes/etc add up.

If you’re going to grid tie it, you could go a lot cheaper since you won’t need quite as much insulation.


2016-09-23 by Unknown

Sweet job. 2 ideas: 1, quick-removal system. Have a trap door system like the drawer used in drive up banking, for the hazardous stuff… screwups get ejected to the outside, with power disconnecting as the drawer moves thru the wall, and 2, like the man said, at least one manual disconnect at the battery box, consisting of a hearty tree stump with the power source cables laying across it, and a nice paul bunyan axe hanging close.

For the quick removal system, maybe even shoot the drawer many feet away from the office on tracks, sorta like a coal miners trolley? get sophisticated and use rail gun power to git er gone?
Seems better than burning down the outhouse or coating it with slime to put out the fire.

Good luck, tom


2016-09-24 by Unknown

Understand why you went solar, but maybe you could evaluate the system a bit further. I’d like to do this too, but I don’t have to, so the money balance is important to me.
So, you spent some dollars on equipment, but what’s the life expectancy of it? 6K might be affordable initially, but what’s the cost to keep things running long term? 5 years? 10 years or more? Batteries need replacing, electrical components have warranty expo dates etc.

Electricity costs about 10cent per kwh. How long to recoup your investment etc.?
Be interested in how you’d look at it if you didn’t Have to use solar.
thanks, tom


2016-09-25 by Unknown

I’m doing this from my smartphone using the microphone Because my fat fingers don’t fit on the tiny screen very well so excuse me if stuff seems weird.I’m doing this from my smartphone using the microphone because my fat fingers don’t fit on the tiny screen very well so excuse me if stuff seems weird. I have a question about daily operations of your neat little box house. Do you run the air conditioner 24 7 or do you only run it while you are actually working there. Next question if you run it only when you’re working there can you give us an idea of the internal temperature when you arrive and how long it takes for your AC to bring the internal room temperature down to where you want it to be. Also how many be to use is that AC and how many amps does it your all. Running your typical load why you are working there approximately how many AC amps are you drawing. Thanks for your help I really enjoy your project Tom


2016-09-25 by Russell Graves

I think that’s slightly overkill…


2016-09-25 by Russell Graves

If you can use grid, use grid. This is not cheaper than grid - I did it because I can’t easily trench grid out to my office. Also, because I find it interesting and have wanted an off grid system to play with for years so I can learn it. It’s not about saving money, and I don’t expect it to save me money (other than “not having to pay someone to trench through basalt”).

Life expectancy on the solar panels is 30+ years. They simply produce less power as they age, but unless they physically fail, they’ll keep producing power many years into the future.

The charge controller and inverter? No idea. Hopefully a long time. They’re around $600/ea to replace.

As far as the batteries, my batteries are deep cycle flooded lead acid, designed for renewable energy use. According to Trojan’s charts, if I run them at a 20% DoD they’re good for 4000 cycles, with around 2700 at 30%. I generally don’t drain them terribly low - I’ve got more panels than I really need, so they spend most of their time full. And I have a backup generator for deep winter conditions. That’s 10+ years on them if they meet expectations, and by that point, I’ll probably have replaced them with a mass of worn ebike batteries, since I seem to accumulate those at a rapid pace.


2016-09-25 by Russell Graves

The AC runs while I’m in there, and is left at a high setting on econ mode when I’m not - typically 80F. That way, things don’t get too hot in the evening, but it doesn’t spend a lot of power trying to keep it cool when I am not out there.

The AC can bring the office temperature down slowly (1F every 5-10 minutes) if I have all the compute loads going on a hot day, or much more rapidly with less power being used. I also can open the windows and door if it’s cool to help vent the office and cool it down.

As far as power use, the AC uses around 750W when operating.


For your next project, I highly recommend planting some trees around your shed. This will dramatically reduce cooling costs, as well as lower external temperatures outside of your shed. If you select a climate-appropriate species and use water harvesting techniques during planting, then it’s possible to support full-grown trees without irrigation. Also, make sure that you don’t plant the trees too close, in order to prevent damage to the foundation.

Here’s some great resources on planting trees to passively harvest rain water:
Image: “Planting the Water”
Video: “Plant the rain—don’t drain it”

I struggle to grow trees out here, either they dehydrate or I overwater them. Rainwater capture doesn’t help when we don’t have rain to speak of for 6 months of the year. When I talk about getting away with stuff because it’s a dry climate, it’s a dry climate.

It would also interfere with my view. :slight_smile: I like the view of the mountains out my door.

Welcome, I assume you found your way here from HN today? Odd bit of content to see traction today.

That’s right. And I didn’t realize when I made my comment that your shed was completed years ago! There must have been a lot of changes since then. HN can be tricky with how old some of the content is.

On the contrary, rain water harvesting is especially useful in dry climates, even during drought years. The idea is that you inflitrate water during rainfall events, and hold on to that water in the soil using mulch and shade. You’d be surprised how effective it is, even without the use of a cistern or any kind of supplemental watering.

In fact, the guy in that video I shared is living in Tuscon, AZ. Brad Lancaster

Of course, if you don’t want trees that’s fine. I just don’t want you walking away thinking that it can’t be done.

1 Like

Less than you’d think, really.

The batteries are the same, the power system is the same, and while I’ve added more panels, those were more for “I need a place to put a small prototype system for the house panels” than anything really required by my office. It’s a bit more power, yes, and… I honestly don’t need it, but it does offset a bit of generator use.

If it can hold for six months, I’m definitely interested! I’ll read up on it more, permaculture around here is an interest of mine, we just get about a foot of rain a year, and only in 2-3 months for the bulk of it.

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If you’re looking for an good introduction into the topic, then I highly recommend Rainwater Harvesting for Drylands and Beyond. It’s a fun read! And very informative.