Power Shed

[JohnnySwank]

Going to piggy back on the 120/12 volt discussion.  How many folks are using a "power shed" to house all the batteries and controllers?  I'm thinking about going in this direction to keep the batteries away from any habitable structures.  Battery failures are rare, but impressive!

Also, I'm leaning on just going 120 with just about everything.  Maybe a tiny stand-alone 12 volt system on the house itself for cell phones, laptop, etc.  Inverters have dropped dramatically in price over the past 5 years and seem much more reliable.  You can buy a nice invertor and OK spare for what you would have paid for one just a few years ago.

Thoughts on this ramble?

[wpowokal]

http://www.fieldlines.com/story/2005/7/25/32151/0328

[MountainMan]

I've posted before about how complicated my system is likely to get.  I will wind up needing a lot of RE, and it will end up being spread around in several fairly distant areas of my land (100 feet away to 400 feet away from the house).  I'm thinking of putting some batteries and a cheap modified sine-wave inverter in each of my "sub-stations", and running wire sized and breakered for only maybe 1000 watts from each "substation" to the main station in my house.  Probably also a bundle of monitoring and control wires along with the juice.

I figure a relatively small amount of storage in the house, with redundant charging voltage coming from all over the property and a really good pair of 48V-->240 single phase inverter/chargers mounted inside the main house.

Separate heavy duty 240V coming from the propane generator straight to the inputs on the main house inverters, programmed for auto-genny start as a last resort.

At a minimum, I can have monitoring capability in the form of checking for incoming voltage from each of my substations, and have all the monitoring and control of the main inverters right there in the power closet in the house (and right next to the main panel for the house).

The tricky part is going to be coming up with the right way to control the charging of the "in-house" battery from so many AC sources.  Need to avoid having one or more substations sitting there "needing to be milked" so to speak, and wasting any energy they make, whilst some other station might be dipping into its reserves at the same time to supply the house with charging current and load current.

I plan to keep the KISS principle firmly in mind while I violate it to pieces.  I'm thinking that maybe the redundancy will make up for some of the complexity I'm adding.

I'm thinking the small amount of in-house storage (probably 4 8-D size batteries) will be housed inside a concrete block "vault" that is vented to the outside.  Anybody think that would be insufficient to contain an exploding 8-D battery?  I have no clue.  Maybe line the inside of the "vault" with quarter inch diamond plate.  Fuse the line inside the vault.

I know everyone who sees this will think "that's way too complex, it will never work".  I know, I know, but nobody has suggested another solution that will work well for distributed energy production.

jp

[satchel]

might be better off with plywood liner as concrete and steel tend to have a draw on batterys.this one i learned the hard way.had a fork lift battery on a cement floor,it was drained in 2 days.recharged it,held for 2 days.finally a freind saw what was happenig,and told me to put some boards under it,then it was fine.

[Waterfront]

I like your «vault» idea, seems pretty neat! Concrete isn't something you can just rip to shreads with the smallest force, so, I think it should make a good protection wall...

How exactly do you plan to vent it? Leave one face open??

[MountainMan]

Vent it by building it against an outside wall.  Hole covered with wire screen near top of vault and another one at the bottom of the vault.  If the walls are combustible material, would probably make sense to use a galv. steel pipe instead of a simple hole.

jp

[Bruce S]

MoutainMan;

 I like your idea of putting these up to AC so there's less voltage loss coming in.

There's a couple of things you could do to keep the monitoring items to a low count.

By using a good Linux program on a laptop you could build in monitoring for each of the power sheds. I am not good enough with Linux yet to program this, but there may be someone on here who is. I have a friend in OK that can , but he charges for his time.

You idea of distrubuted power is similar to what the big boys use, just that yours wont be choking the air.

To vent to into one of those real small low power computer fans. This will help create a stir in the air and if it dies from the fumes , they are pretty cheap. They can even be wired to a small solar lawn light to run the 12vdc ones will start to trun even with just 3vdc. Couple small NiCds worth.

As you go down the road and comfortable with a working setup you could always add feeding circuits between the sheds to keep the waste to a min.

Looking real good!!

Merry Christmas!!

Bruce S

[thirteen]

I plan on putting my batteries in a building that will be in a bank of dirt with a cement floor and insulated walls 80 feet from the house.  Be sure and seal everything off there is not much you can do to clean up a rat or mice that are toated with your system when they get in. The dirt bank is to have a constant SP tempature and I can be gone with no worry about freezeing tem.