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Comment by briHass | Hacker News Reader

At least around here, backup generators are for outages that happen when solar would be mostly useless: heavy storms or during Winter.

Cheap and safe batteries paired with solar will help, but the capacity will likely still be an issue for extended outages.

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An islanding solar system with storage is not useless during storms or the winter, it still generates during the day. Not sure where your "around here" is, though.

Do solar panels ever get trapped under large amounts of snow the day after a strong snow storm?

Sure, but with a couple inches of snow on them, mine still generate power. And in areas which regularly receive snow, roof pitches are generally steep enough to encourage it to slide off else the building would suffer overloading. Worst case a push broom or squeegee with a very long handle works wonders.

Also fairly trivial to rig up a resistive heating system for melting the snow in cases where the above isn't possible. Even possible to automate it based on time of day and expected power input.

> Also fairly trivial to rig up a resistive heating system for melting the snow

Couldn't you just run power through the solar cells as if they were giant LEDs? Or don't they like that?

It is possible to back-feed power through a solar cell such that it emits photons (or maybe just heat - I'm not entirely clear on that). But all solar panels include diodes to prevent this and provide protection from hooking them up in reverse.

Ah, makes sense. As you mentioned though, easy enough to fit some thermal heating foil on the backside unless you're using bifacials.

It does happen occasionally, but it's rare that my panels are covered for more than a day or so. Heavy snows almost always slide off within 36 hours - sometimes a light snow (~3" or so) can cover it for a while because it's not heavy enough to slide off from gravity. The panels are very low friction compared to a normal roof.

Yeah - When covered in even a moderate amount of snow, output drops almost all the way off. I had thought that being black, they would melt off quickly, but that doesn't appear to be the case. As an aside, my daughter's neighbor has solar and after a big snowstorm, a foot of snow slid off his panels, right into the side of her house destroying a basement window and blowing shattered glass 5 foot into the basement.

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