Shed

Re: Shed

What you're thinking about is what I did in 2007. But being near the ocean, I suspect our temperature range is less than yours. That said, we do have -20c temps here, and with my batteries insulated for Winter (which I skipped the last 2 years) their temp seldom drops below 0C.
I built the shed especially for this and one of the great beauties of the settup is that I located the panel rack on the South wall, hinged at the top, up next to the roof. In Winter, with the sun low in the sky, I drop then down to the vertical position, no snow collects on them, and the light reflected off the snow adds to the normal sunlight, really increasing output. Then come Spring, the panels are tilted up from the bottom for best Summer power harvest. Another advantage is that if there were some unfortunate happening that burned the house, my solar system would be spared. Likewise the other way around. Inverters and all are in the shed and only the 120 VAC is fed underground to the house. Very happy with it.

Re: Shed

Just a heads up, if you are unable to tilt your panels to the vertical for the snow season, it's going to be a real pain in the butt trying to keep them clean. Been there, done that, and now except for the Spring and Fall tilt change, they are out of sight, out of mind and there's no way I'd want to go back tot he way things were.
Batteries by the way, do create heat within themselves during charging and discharging, so if well insulated, that heat does tend to help keep their temp from going too low.
Good luck in whatever you do.

Re: Shed

not the shed, the panels....there are some pictures here on the BB of panels that must be 15 - 20 feet in the air during the summer and snow level in winter.. don't remember where though, maybe BB or Niel??

Re: Shed

My family has a cabin with solar in Northern Michigan (sort of curious how far away you are from me) and I've learned a few things. First off, even in an insulated garage the batteries will average about 30-35°F most of the winter. This isn't too bad but you'll give up about 40-50% of the capacity. This appears to be greater than Bill's chart but that's because of the afternoon overcast skies we seem to get being near L. Superior. Sun until 11am and then clouds. At least at this time of year that is finally starting to turn around.

Lack of good sun + cold is a big issue. A battery will charge around 90% efficiency from 0-79% SOC or so but after than the efficiency drops off dramatically. At 90% SOC half the energy being put into the battery is wasted. It you have solar that's fine - trickle charge the battery until it's full. In winter with a generator it's not that easy. So now it's cold, batteries lost capacity and you can only really charge to about 85-90% of cold weather SOC before you're wasting gas. Winter can be tough. Just be aware that a generator is a requirement and it's use is highly dependent upon the weather.

The panels are mounted on a pole and have about a 45° tilt. Very very rarely is there an issue with snow sticking. We also put an 1.5 inch gap between the panels to allow for snow to melt without icing up and cracking the frames (not sure if that is a real concern - but why risk it). We never really considered a roof mount because we couldn't figure out how to mount the panels in a way that allowed the gratuitous amount of snowfall to play nice with panels - ice dams, where would the snow go when it melts, would the snow drift on the roof and cover the panels, etc...

Take a look at my family's set up and drop a comment or question - I'm more than happy to explain why I did something the way I did and to help out another off-gridder.

Re: Shed

One thing you might consider is installing a solar hot water panel (2X8 ft.) on the South side of your shed about midway up the wall. Inside place a 55 gal. drum of antifreeze as to allow natural convection from panel. Elevate your batteries to allow the same convection to take place. Place a single PEX pipe around the outside parameter of the batteries. On some here at timberline in the mountains of CO. we have had to run a water line at the bottom of the water solar panel to keep the snow depth from burring the panel. The winter temps range as low as -40 degrees or so. Partial cloud cover and wind snow drift is usually a daily occurrence effecting solar isolation. Most of these systems are for repeaters etc. They must work 24/7. A greenhouse wax vent system controls any chance of excess heat on the batteries. Battery temps usually range 50 degrees or higher. The object is to have full avibality of storage capacity. We tilt these water panels 15 degrees as our summer temps are often below freezing at night. All solar electric panels are installed on poles and above snow and rubbing animal levels. The expense of the heating system costs less than one battery. Remember if at your location you are getting to much heat you can partially block the panel.

Re: Shed

Jungle Jim wrote: »

Hi Bill
Thank you for the warning about a generator fire taking out the whole system. I am in the middle of planning our off-grid farm's power supply system and should have realized that I was putting all of my eggs in one basket. Now i think we will build a seporate shed for the 20kW Detroit 3-53 and its fuel tank.
Dennis

My battery inverter shed is seperate from the generator shed for the same reason. Hopefully, there will never be a fire, and if so, we could get it out in time.

Re: Shed

westbranch wrote: »

not the shed, the panels....there are some pictures here on the BB of panels that must be 15 - 20 feet in the air during the summer and snow level in winter.. don't remember where though, maybe BB or Niel??

no it wasn't myself or bb, but i believe you are referring to dave sparks if i remember right and occasionally i do.:-)

Re: Shed

i can picture what pics you are referring to in my head, but if it wasn't dave sparks then i'm drawing a blank. sorry.

Re: Shed

Here is a "Tuff Shed" from Home Depot.

I helped a DIY do this upgrade from a 25 year old system. The 3 panels on the roof are new and run into the MPPT. The 12 on the ground are old and run into a PWM Tristar at 24 volts. The ones on the roof would shed snow quite well, though this site will probably never get more than 12"

The house is in the woods +/- 460' down a north slope from this power room. The inverter monitor still works at this distance too. (Magnum ME-ARC/BMK) The array on the roof can be tilted from 30-60 deg +/- .


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Re: Shed

niel wrote: »

solarevolution,
would those older pvs happen to be solarex?

Yep. Good eye! Still producing. They could be 30 years old.

The other old ones are SP75 "hurricanes"

Re: Shed

Solar Dave, I burnt a 56 buick with an electric fuel pump. The cam that was suposed to operate the fuelpump had the lobe wore off. Luckily the fire dept disconnected my battery cable and I could still run it after I replaced a couple wires.I connected it to the ignition switch so pump wouldn,t run. My wife got out of the car without turning off the ignition switch. :Dsolarvic:D