Solar Collectors Melt off snow

Despite over 18″ of snow landing just the day before, a little bit of sunshine melts the snow off our Portland office’s solar collectors just fine.

To follow up our report a few weeks ago that solar hot water collectors still generate heat – even when buried by snow – we’d like to remind people that even after serious snow storms you don’t need to worry about getting the snow off your panels.

While it’s true that for short periods of time the snow may reduce your solar gain, the risk of damaging panels, and more seriously, yourself, while scrambling around on your roof far outweighs a minimal boost in performance.

Generally speaking, if there’s not enough sun to melt off the snow, there’s not enough sun to harvest for hot water or electricity.

Since your solar panels are conveniently pointed towards the sun and facing south, on the next sunny day after a snow storm the sun should do its job and melt off the snow (which will tend to slide off anyways), allowing your system to get back to making hot water or electricity!


Christof says:

While I’m all for safety, the question of snow and power production loss is actually a lot more complicated than this entry makes it out to be. Roof pitch, panel pitch, type of panel, outdoor temperature, cloudiness, system size, amount of snow, type of snow (will it blow off, etc.) — are just a few of the many variables that can really change the equation in terms of just how much power production you will lose if you let snow sit on your system.

In fact, I am sweeping our system in Colorado this year, and am keeping track of what the power production savings are.

Fred says:


Appreciate your comments and link, and fair enough – our post is intended mostly for our customers, where we’ve considered the implications of snow load in the design of the system.

Generally we try to ensure there’s enough room for snow to slide out from underneath collectors so it discourages serious accumulation. And we definitely discourage people from trying to clear off the collector itself!


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