Will my system survive winter?

[Bhilton]

Hi All!

I built a small cabin 16x22' this summer and insulated the walls with R20, floor with R28 and ceiling with R28.

I installed a Growatt 3500 US with an SOK 48v 100ah. I insulated the battery with 1" rigid foam (R6 I believe) but I did not insulate the Growatt, it's hanging on the wall temporarily for now. I couldn't get the cabin interior done and it's boat access so right now I'm stuck waiting for the lake to freeze before I can get back to it (6 hour drive away).

System is fed by 5x 405W Canadian Solar all-black panels in series. I left their angle set for that region's winter sun and they are pointing due south with direct sun most of the day (excluding ~first hour in the morning and ~last hour in the evening)

All summer the system worked great, running my medium size fridge 24/7.

I have not been there since October 20th and temperatures have stayed above freezing until now. Temperatures next week: Daily highs around -6C/21F and lows -16C/3F.

I left the system connected and running, I'm hoping the constant ~1Amp the Growatt draws and the insulated battery inside an insulated cabin will keep the battery above zero and functioning. All appliances are off, including the fridge.

As soon as the ice freezes, I plan on going to check the cabin and system out.

What do you all think is it going to be working when I go there next?

Anyone with a similar experience, can you share how it worked out for you?


Thank you!

-Bill

 

[Daddy Tanuki]

Has it snowed in the area of the Cabin? (covered panels). The SOK has low temp shutdown so worse case you have to warm up the battery before it can charge. nothing should be damaged at worse you have a low temp/low voltage shutdown.

do you have a method to heat the cabin other than via electricity? as long as you can warm it up it will accept charge form the panels.

I bet you arrive and its sitting around 75% with no issues but have no proof, just my thoughts after watching my DIY system for a couple of years

 

[seneysolar]

Hi All!

I built a small cabin 16x22' this summer and insulated the walls with R20, floor with R28 and ceiling with R28.

I installed a Growatt 3500 US with an SOK 48v 100ah. I insulated the battery with 1" rigid foam (R6 I believe) but I did not insulate the Growatt, it's hanging on the wall temporarily for now. I couldn't get the cabin interior done and it's boat access so right now I'm stuck waiting for the lake to freeze before I can get back to it (6 hour drive away).

System is fed by 5x 405W Canadian Solar all-black panels in series. I left their angle set for that region's winter sun and they are pointing due south with direct sun most of the day (excluding ~first hour in the morning and ~last hour in the evening)

All summer the system worked great, running my medium size fridge 24/7.

I have not been there since October 20th and temperatures have stayed above freezing until now. Temperatures next week: Daily highs around -6C/21F and lows -16C/3F.

I left the system connected and running, I'm hoping the constant ~1Amp the Growatt draws and the insulated battery inside an insulated cabin will keep the battery above zero and functioning. All appliances are off, including the fridge.

As soon as the ice freezes, I plan on going to check the cabin and system out.

What do you all think is it going to be working when I go there next?

Anyone with a similar experience, can you share how it worked out for you?


Thank you!

-Bill

I suspect you will return to a shut down system. Not enough sun, nobody to brush snow off the panels, temps below the bms cutoff, and cumulative inverter idle consumption.

Black frames do shed snow pretty good when theres sun. Ultimately my bet is mother nature wins.

When you go back, bring a small generator and a 48v battery charger.

 

[Daddy Tanuki]

I suspect you will return to a shut down system. Not enough sun, nobody to brush snow off the panels, temps below the bms cutoff, and cumulative inverter idle consumption.

Black frames do shed snow pretty good when theres sun. Ultimately my bet is mother nature wins.

When you go back, bring a small generator and a 48v battery charger.

he should have his inverter LBCO set high enough that it will shut down prior to the BMS shutting down if he set it up correctly.

 

[Bhilton]

Has it snowed in the area of the Cabin? (covered panels). The SOK has low temp shutdown so worse case you have to warm up the battery before it can charge. nothing should be damaged at worse you have a low temp/low voltage shutdown.

do you have a method to heat the cabin other than via electricity? as long as you can warm it up it will accept charge form the panels.

I bet you arrive and its sitting around 75% with no issues but have no proof, just my thoughts after watching my DIY system for a couple of years

Thanks! I have a Williams direct vent propane furnace installed, tested and ready. I have a generator ready too. Heating up the cabin shouldn’t be an issue.

I hope to get there in first half of January.

 

[Bhilton]

I suspect you will return to a shut down system. Not enough sun, nobody to brush snow off the panels, temps below the bms cutoff, and cumulative inverter idle consumption.

Black frames do shed snow pretty good when theres sun. Ultimately my bet is mother nature wins.

When you go back, bring a small generator and a 48v battery charger.

Thanks! I know it could go either way, I am totally experimenting. Generator is there and ready. Propane direct vent furnace ready.

Angle of panels is about 70 degrees, optimal for the area is 68 over the winter. I was hoping the snow won’t stick to them too much.

It has snowed a foot and a half up there, but had rain and some above zero days too, so I don’t know how much accumulation is there.

48v charger is a great idea!

 

[Bhilton]

he should have his inverter LBCO set high enough that it will shut down prior to the BMS shutting down if he set it up correctly.

Lbco is set at 48.6v i think, I had set it the highest the growatt would let me.

 

[Bhilton]

Here are some photos.

 

[Daddy Tanuki]

Here are some photos.

View attachment 262872View attachment 262873View attachment 262874View attachment 262875View attachment 262876

Our Canadian cousins get all of the nice things dammit!

 

[Madcodger]

First, great looking "camp", as we call them in Maine. We have many similar places near us, and I'm looking for a new one myself after selling our full time island home this year. I'll be interested to see how things fare so please do keep us updated.

I think snow building up at the base of the panels will be your biggest problem. I have two ground arrays and find that I need to clear the snow away regularly to avoid creation of an ice dam at the bottom. The snow melts off fairly well, but then it compacts at the bottom and over even a few days it turns to a solid block that just gets bigger and bigger unless you remove the snow soon after it falls. If you wait until it freezes it's going nowhere until it melts in the spring I'm actually thinking about moving those panels to a new, much higher rack next summer for just this reason.

 

[Brucey]

May want to consider going fully vertical at least for winter snow shedding. I get build up on the base of mine but a quick blast with backpack leaf blower scours that right out. But I'm here every day.

 

[Daddy Tanuki]

May want to consider going fully vertical at least for winter snow shedding. I get build up on the base of mine but a quick blast with backpack leaf blower scours that right out. But I'm here every day.

that or build the array a little bit higher. think of it like the snow parks and ski resorts, they build infrastructure to match the average height of the snowpack... that why in the winter the artificial snow makers and lifts seem like they are at the perfect height, but int he summer they are about 12 to 16 feet above the ground.

 

[Bhilton]

that or build the array a little bit higher. think of it like the snow parks and ski resorts, they build infrastructure to match the average height of the snowpack... that why in the summer the artificial snow makers and lifts seem like they are at the perfect height, but int he summer they are about 12 to 16 feet above the ground.

I will definitely consider going a bit higher. The pictures don’t do it justice, the panels have 2’ of clearance below them to the ground, and the slope of the shore is quite steep right beneath them, from what I have learned ot is not likely to get much more than 2’ of snowpack, but I didn’t consider the melting running off and creating ice buildup and thus the next snow storm has a solid base to form on, can’t wait to go check it out. Almost 2 months since I was there last. My only peace of mind is that I ran that system from May to October (with panels in a worse location) and every time I went up, the battery was full and the system it never acted up or anything!

Battery low temp cutoff is the only thing I am think will end up happening. But fingers crossed, just maybe my insulated cabin and insulated battery will win! Haha

 

[Bhilton]

First, great looking "camp", as we call them in Maine. We have many similar places near us, and I'm looking for a new one myself after selling our full time island home this year. I'll be interested to see how things fare so please do keep us updated.

I think snow building up at the base of the panels will be your biggest problem. I have two ground arrays and find that I need to clear the snow away regularly to avoid creation of an ice dam at the bottom. The snow melts off fairly well, but then it compacts at the bottom and over even a few days it turns to a solid block that just gets bigger and bigger unless you remove the snow soon after it falls. If you wait until it freezes it's going nowhere until it melts in the spring I'm actually thinking about moving those panels to a new, much higher rack next summer for just this reason.

I will update this thread once I get there and come back. For sure.

 

[Daddy Tanuki]

dude that is like perfect... you could cast a line from your front door and haul lunch or dinner in.

 

[Bhilton]

Update, ice is 5 to 8” and camp my neighbor checked things out. Panels not doing great but system is still alive! Photos below. I will be going up there in January and I will update this thread after that.

The SOK 48v 100ah battery, sandwiched in 1.5” rigid foam panels, inside a well insulated airtight cabin, is holding on! Night time has been kissing -20C lately and day time -15C. Forecast for next couple weeks is around zero C during the day.