Snow-covered solar roof

Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall. 

Today, we have a question from a listener. Margret Bulmer wonders whether solar panels still work in the winter when they’re covered with snow.

We had Maddy Adams and Luci Jones from our Possibly Team look into this question. Welcome, Maddy and Luci! 

Maddy Adams: Hi, Megan!

Luci Jones: Hey!

Megan Hall: how does snow affect solar panels?

Maddy Adams: It’s a good question, and we needed some help to answer it.

Luci Jones: So we spoke with Andrew Gabor. He works for Brightspot Automation, a company that makes equipment to test how well solar panels are working. 

Maddy Adams: He told us solar panels are pretty low maintenance.

Andrew Gabor: It’s really elegant, there’s no moving parts, it’s just this black box, you stick out in the field and, and convert sunlight to electricity and can do that for 30 years with no problems.

Megan Hall: That sounds easy enough!

Luci Jones: And he says, solar panels actually work pretty well in the winter… 

Andrew Gabor: In wintertime the panels get cold. So some people think, oh, that could be a problem. And it turns out, it’s not. 

Maddy Adams: Andrew says solar panels are actually MORE efficient in the winter.

Megan Hall: Really? Why? 

Maddy Adams: Well first of all, solar panels create energy from the light of the sun, not the heat of the sun. 

Luci Jones: Meaning… you don’t need to live in a hot place for your solar panels to work well.

Megan Hall: Got it.

Maddy Adams: But there’s another reason too… Bear with us here, it’s gonna get a little technical… 

Megan Hall: Ok…

Luci Jones: Solar panels work to produce electricity, which is the flow of tiny charged particles called electrons. 

Maddy Adams: Electrons resting in a solar panel get excited when they’re hit with sunlight 

Luci Jones: and the difference between their resting energy and their excited energy is what produces power.

Maddy Adams: when it’s hotter outside, the electrons already have a higher resting energy… 

Luci Jones: so when they’re hit with sunlight, there’s less of an energy difference between their resting and excited states.

Megan Hall: So, a warm electron that gets hit with sun creates less energy than a cold one that gets hit with sun?

Maddy Adams: Basically. Or, close enough for us non-physicists.  

Luci Jones: That means, solar panels don’t just work well in the cold, they thrive in the cold!

Maddy Adams: It’s pretty cool (pun intended). 

Megan Hall: But what about Margaret’s question- do solar panels still work when they’re covered with snow? 

Maddy Adams: Andrew says, not really. 

Andrew Gabor: Their efficiency will be very low when they’re covered with snow. They can work a little bit if there’s a thin dusting of snow, some sunlight can get through it. 

Luci Jones: But if there’s no light hitting the panel, it can’t generate electricity.

Maddy Adams: Still, this isn’t usually a big problem. Solar panels are often installed on an angle to get the most direct sunlight.

Luci Jones: So, if a panel has snow on it, with a little help from gravity, the snow slides off. 

Megan Hall: When do solar panels work their absolute best?

Luci Jones: Andrew says it’s a combination of factors:

Andrew Gabor: When the sun is shining the brightest, when the panels are pointed most directly at the sun, and when the temperature is coolest. 

Maddy Adams: Overall, the amount of sunlight is the most important, so summer months are still when solar panels produce the most electricity. 

Luci Jones: But don’t shy away from getting solar panels just because you live in a snowy, cold place! 

Maddy Adams: And over a year, if you have enough solar panels in the right location, you can  produce more electricity than your house needs. 

Megan Hall: Great! Thanks, Maddy and Luci!

That’s it for today. For more information, or to ask a question about the way you recycle, use energy, or make any other choice that affects the planet, go to the public’s radio dot org slash possibly. Or subscribe to us wherever you get your podcasts. 

Possibly is a co-production of the Institute at Brown for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio. 

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