# where to put batteries and power house for solar powered house



## MrsRaspberry (Sep 21, 2004)

In final stages of site planning for new homesite. We hope to be off grid completely and are wondering where to put the components of our system. We have designed our home with passive solar in mind- no A/C for sure and wood heat back-up. We hope to have the panels mounted on the ground not the roof. We have plenty of room so that is not an issue. We will have a full basement. We'd like suggestions on where to put the other components. We have no attached garage and the other outbuilding is within 100 ft (I think). But is will be unheated and we get well below freezing here in SW WI. Also, we plan on a generator for back-up power. Thanks in advance for the help!


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## Nimrod (Jun 8, 2010)

I'm not a solar guru but have done some thinking on the special needs of a solar system in a cold climate.

Solar panels on a stand on the ground will be easier to clean the snow off of. Even a small area blocked by the snow reduces the output by a lot. 

Batteries lose up to 80% of their capacity in the cold and discharged ones can freeze. They need to be someplace warm but with a vent to the outside for the hydrogen gas they emit. 

A generator will start much easier if it's warm but the exhaust has to go outside. You want the generator to start when you need it.


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## TnAndy (Sep 15, 2005)

I'm working on a ground mounted 10kw system for guy now. Building the support out of 2" galvanized pipe ( two 'legs' in the ground, one sloping on the two legs. See photo below, this is another system I built using the same design.) I use 3/16"-2x2 galvanized angle across the top of the pipe to mount the Enphase inverters (pictured)(which you would NOT have in an off grid system), and also the panels themselves.










In the above, the ground sloped sharply UPHILL, (35-40 degrees) so the clearance under the panels is nearly the same as the slope of the panels. But in a level ground deal, you'd have a fair amount of room under the back of the upper end.










The fixed, ground mount panels (2500w) are grid tied only. The panels on trackers are grid/off grid, connected to a battery system, which is in that 'power house/greenhouse" you see the end of below the lower set of tracking panels. (Two different types of grid tie systems)

This current system, we're mounting the lower row of panels about 4' off the ground at the bottom edge. The slope of the racking is 45 degrees ( to give a better power factor in the winter....38 degrees is the year around recommended here). There will be three rows of panels in portrait layout, (versus the two rows in the photo above) each panel is 66" tall, so they are 16'6" up the 45 degree slope. That puts the back of the top row about 12-14' off the ground ( ground in this deal also slopes away to the back about 2' down from the front). 

This guy doesn't need one, since it is grid tie only but it would be plenty of room to put a small "power shed".....say 8x12..... under the panels mostly......which is how I would do it in your case. Keep the low voltage run from the panels as short as possible, put your charge controller(s), inverter(s), etc in that shed, along with the batteries and the generator. Insulate it WELL for you climate, put the diesel fuel or propane tank (for the generator) right outside the shed.

Thats my two cents worth.....


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## Bellyman (Jul 6, 2013)

Impressive, Andy!!

As for where to put the batteries, as near the panels as is practical. If you are running a long distance, there can be pretty serious line losses for low voltage. If running the panels in series for higher voltages, it gets easier. You probably already know all of that.

If I were building from scratch, I think I'd probably build in a place for the battery bank, charge controller(s) and inverter(s) in a "mudroom". Attached to the house, heated (at least to some extent) but with the batteries contained within their own box of sorts so that they could ventilate. It would provide for easy access when you need to service / clean / inspect your battery bank and would be a place you'd pass by all the time to remind you to do so. It would (hopefully) be in a place you didn't have to have a lot of stairs to go up or down if you needed to replace batteries (usually happens every so many years, usually sooner than you remember).

Another possibility that could be quite similar might be in a basement area if it were a "daylight basement"... you know, the kind of house where you walk in the front of the house on one floor but if you come around back, you can walk into the basement door without going down any steps... that kind of thing.

Just my thoughts.


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## Gray Wolf (Jan 25, 2013)

Our house has a 'daylight basement' that is at ground level on two sides. We have the battery / inverter room tucked back in a burried corner. Warmer than outside in winter and cooler in summer. Batteries are in a sealed box with hydrogen vent line up and outside - fresh air intake at bottom of the battery box. Louvered door on the battery room. 

I don't know if it is required but I put a lock on the door to keep unauthorized guests from playing with the gear. You might consider locking it all up too. Dangerous stuff in there.


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