Clear the Snow Off Your Solar Panels, or, Don't Believe the Salesman -- Who Knew?

Take this as clear evidence that if you have solar panels in a snowy climate, remove the snow as soon as possible.

Although, as I’m always willing to give others the benefit of the doubt, maybe we had meteorological conditions conspiring against us.

So, about a week ago, we got about two inches of snow. This being Idaho in December, we should have seen it coming.

With the snow came a week of below average temperatures, with mornings in the single digits or below zero, and afternoons rarely peeking over 20 degrees. Naturally, that meant the snow on the 16 panels on the roof of our two-story house didn’t melt off. In fact, it crusted.

Now, before we had the panels installed, snow was my first question: Do we have to clean the snow off of them in the winter?

You might, the salesman said, if you get a really good storm. Otherwise, the panels “run hot,” and the snow will melt off.

Haven’t seen that happen yet. But, again, I have to lay some of the blame with the cold temperatures.

Clearly, you can see after we got up on the roof Saturday to clean the panels (using a roof rake with a pool noodle attached as a squeegee) we got significantly more power generated than with the snow still in place. Of the methods I saw for snow removal, this seemed to be the one that promised the most return for the time invested.

(The method I’m most dubious about is spraying the panels with water. Maybe I’d try it once, but given we’ve got a two-story house, it’d be messy and difficult and I’m not sure I want all that excess water up there, even if most of it drips off.)

A friend who had panels installed at about the same time said his salesman said other wavelengths of light would get through the snow and help generate power – something his monitoring and customer service showed did not come to pass. We saw the same with our own monitoring, as the graphs show.

So, if you want maximum power, be prepared to clean the snow off. Or pray for wind to come with the snow.

Can you guess at about what time we cleared the snow off the panels?

Clearly, removing the snow was a good thing.

It snowed two days later. And will snow again tonight. But tonight's snow should be accompanied by 25 mph winds, so hopefully the snow will fly off.

I expect, given the scarcity of sunshine, that December will be our worst month for electricity generation. Knowing we’re getting more power with the snow gone is a bit more solace than listening to the salesman can provide.

Overall, we’re still pleased. Last month, we paid about $22 for electricity from the grid. Same billing period last year saw us pay $66. That still means with a payment of $90.11* for the panels, plus applicable fees and taxes, electricity still cost us more this month than it would have otherwise, but we’re looking long-term. It’ll be interesting to see where we are a year out from having the panels installed (and working at full-throttle, we had a month last year just after the panels were installed that things were pretty glitchy).

So, should YOU clean the snow off your panels?

If you’re looking at a string of cold weather, definitely. The snow will not disappear on its own if meteorological conditions aren’t conducive to melting, and your power generation will suffer.

If the snow comes with wind and is then followed by more moderate temperatures – here I’m guessing in the high 20s to low 30s, without the intervening below zero – maybe waiting a day or two for natural melting will pay off. You’ll have to decide the benefits of snow removal versus the expenditure in time (and, in our case, a climb up to our second-story roof). I’ll let you know if this pans out after our next storm, which is set to arrive later this week.

*Mileage may vary. Right now, Blue Raven is sending us a check for $90.11, a deal that’ll last for the first 18 months, and we’re turning that right around with additional cash on the loan, so the math is a little off.