Do Solar Panels Perform In Winter?

When I heard that the Colorado government was offering incentives to any resident homeowner that installed solar panels, I was beyond excited., then monstrously skeptical. My partner and I are gearing up to buy our first home and like many first time buyers WE WANT EVERYTHING. Everything includes sleek solar panels. As I looked into the incentives being offered, I watched the blizzard by my window unfold. I started with weather concerns. The longevity of solar panels in sporadic and harsh conditions made wonder if that’s why our government was offering tax incentives.

What Do They Mean By ‘Sunshine’ Anyway?

From sudden hailstorms to unpredictable winters, are solar panels worth the investment? More sun, more energy, equals more energy and savings right? It’s common gossip that Colorado gets 300 days of summer but Colorado State University’s Nolan Doesken says it just gossip.

“This is a question that comes up several times per year. You will find in many Chamber of Commerce publications from all areas of Colorado that we get at least 300 days of sunshine each year. The only problem is, there is no official definition of “days of sunshine” so there is no data set that you can easily turn to.

Have you ever wondered if anyone actually keeps track of stuff like this? It turns out that for many years, three locations in Colorado have operated an instrument called a ‘sunshine switch’ — Pueblo, Denver and Colorado Springs. If this instrument is cleaned and perfectly calibrated (which it rarely is), it can tell you minute by minute each day when the sun was shining. We did a study over ten years ago based on these three stations and found that for Denver if you count every day when the sun came out for at least one hour, that then you could come up with an average of around 300 “days of sunshine” each year.

But my assumption is that most people, if they heard “day of sunshine” would assume that meant it was a sunny day. The National Weather Service did establish a criterion for determining clear, cloudy and partly cloudy days based on sky cover. Any day, with an average skycover of 30 percent or less was considered a clear day, while if the sky cover was 80 percent or more, (averaged from hourly sky condition reports between sunrise and sunset), it was considered a cloudy day. Anything in between counts as “partly cloudy”. Based on this definition, there are 115 clear days, 130 partly cloudy ones and 120 cloudy days, on average, each year. Over in Grand Junction the number of clear days is great (137) but the number of cloudy days is almost the same (121).

But the fact is, here in Colorado and much of the Rocky Mountain region, there are relatively few totally clear days but a whole lot of days when the sun peeks out at least a little. Therefore, we tend to brag about our sunshine — but mislead folks along the way.

Of course the answer will differ from one location to another in Colorado with the most sunshine occurring down around Alamosa with the least around Boulder and in the northern mountains of the state. In the Denver area there are probably only 30-40 totally overcast days per year, and some of them are even fairly bright — about 300 days would have at least one hour of sunshine sometime during the day, but only about 115 days per year fit the classic definition of ‘clear’.”

Taken from an interview in the Westword.

Hail Hell?

Newer solar panels are built to be ‘hail resistant’. This make me shudder as I glance out to the states of my cars hood. My doubt was cleared up by consistent evidence of structural integrity and replacement/repair policies.

Solar panels, across the board can take a fairly heavy beating and keep rolling. Anything under a golf ball or baseball (depending on the model and size), and your panel will keep operating. Every company offering solar panels have pretty reasonable replacement/repair options. Some companies can even do it for free.


The temperatures don’t affect the efficiency of panels. Availability of sunlight will always be the most deciding factor. As snow covers and builds on panels, that light is blocked. I imagined having to go outside to knock off the snow. I imagined that I wouldn’t be a fan.

Most home panels are angled to be at an optimal ray absorbing angle. As snow builds, it gets heavier and often gravity will take it off for you. It isn’t recommended to push or rake the snow off yourself. the potential for injury or accidental damage to the panels is too high. There is an option to call a professional to take care of it.


Jeff Wilson
Author: Jeff Wilson

Jeff is one of the owners of GayDenver and one of its writers. He is a Denver transplant who loves the city and the proximity of the mountains. He is happily married to his husband and loves thinking with his furbaby Thayella.

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