Solar panels were, are, and will always be associated with the sun. Because of this, it’s natural for just about every homeowner to think solar panels perform at peak efficiency and produce the most electricity during summer, the sunniest time of the year.
Even major solar companies across the nation spread the message through advertisements, sales pitches, eBooks, blogs, and consultations that summer is the best time to go solar! But is that really true? Should homeowners associate the winter with low solar production, efficiency, and savings?
Well, in today’s post we’ll be looking at the truth behind going solar in the winter.
Do Panels Perform Better in High or Low Temperature?
We all know that winter equals cold weather. The national average temperature in January of 2020 was 35.5 degrees Fahrenheit. For most states, the difference between average summer temperature and average winter temperature can be more than 45 degrees! But what do all these temperature statistics mean for a homeowner considering solar?
While it may seem counterintuitive, high temperatures can cause solar panels to be less efficient because of the law of thermodynamics. Just like a computer or phone, solar panels can overheat. This means that the hotter the temperature the worse the panels will perform. Thus, panels are actually more efficient during the colder fall and winter months.
But how much of an effect do temperatures have on overall panel efficiency?
Well, the solar industry typically tests its panels as if they were in a 25 °C or 77 °F environment. The average panel will drop by about 0.05 percent for every degree Celsius over that tested temperature. If panels reach an internal temperature of 35 °C (95 °F), they will produce power with .5% less efficiency than their original grade.
For most states, this decrease in efficiency only occurs during the summer months, meaning that panels are technically more efficient during the winter. Temperature plays the biggest effect in hot states like Arizona, California, Florida, or Nevada, where panel temperatures can exceed 95 °F for almost half the year. During the winter, all solar owners will avoid any losses to solar panel efficiency and monthly electricity bill savings independent of the state they live in.
Originally, solar panels performed poorly in freezing temperatures. However, the solar industry was quick to develop a layering design to protect solar panels’ internal temperatures from getting too low.
Through the use of tempered glass, aluminum casing, and a steady back sheet, solar panels can stay at the ideal internal temperature of 40 to 55 degrees Fahrenheit even during the coldest winter storms. However, scientists have yet to discover a way to keep panel’s internal temperatures cool during the hotter summer months.
Thus, the winter months should not scare homeowners away from going solar, since lower temperatures are actually ideal.
Panels Don’t Produce Energy in Cloudy Weather…
Well, if cold temperature doesn’t play an effect on solar panel efficiency, clouds from winter storms must, right? It’s a common misconception that solar can’t produce energy when sunlight is blocked by clouds.
However, just how you can get sunburned on a cloudy day, solar panels still produce energy when the sun isn’t beaming bright. This is because solar panels don’t require direct sunlight to produce energy. Unfortunately, indirect sunlight is not as effective as direct sunlight, which means that solar panels will produce 10-25% less electricity on a day that has a large quantity of cloud coverage.
Despite this unfortunate truth, there are some situations in which clouds can actually increase solar panel energy production. Some winter days are filled with individual clouds that pass slowly in the open sky. These lone clouds reflect direct sunlight, causing more of a higher concentration of light to hit nearby solar panels. Thus, for a brief amount of time, a residential solar system can produce a burst of extra electricity. This is called the cloud edge effect and commonly occurs during colder fall and winter months of the year.
Although homeowners should never depend on lone clouds to boost their energy output, they can have peace of mind knowing that clouds don’t always have such a negative effect on solar production!
Does Snow Block Production?
Dozens of states are accustomed to winter storms that can dump inches and even feet of snow in less than a day’s time. When the snow from a storm builds up on a roof, any solar panels are covered in a blanket of snow. This external covering is one extra layer for the sun to pass through and will even reflect a good portion of sunlight that will never reach the panels. Depending on the depth of snow, panel production typically sees a 20-30% loss when covered in snow. That is a massive amount of savings being lost, especially if you live in a place where it snows throughout the winter.
Luckily, the surface of solar panels tends to heat up throughout the day. This causes any built-up snow to melt quickly and disappear throughout the day. In some locations, snowfall might be high enough that solar panels do not have enough time to melt all that snow buildup.
In these locations, we suggest that homeowners buy the appropriate tools that allow them to safely remove excess snow from the solar panels. All in all, snow shouldn’t have a long-term impact on the effectiveness of your panels.
About Shop Renewable Energy
Shop Renewable Energy started because of a simple question: Which company should we go solar with? As we navigated going solar for our own roofs, we discovered that there were dozens of local and national companies offering different discounts, solar panels, ownership agreements, and more. With hours of research, we made our decision, but we recognized that many homeowners are choosing their solar installers blindly. That’s where we came up with the idea for Shop Renewable Energy. As a small business, we look to improve the lives of our customers by making the solar journey more simple than ever. We do this by connecting homeowners with the best local solar companies in your neighborhood. We hope that you can utilize our business to shop for the best renewable energy in your area!