How does solar energy work in the winter?

Wind chills well into the negatives. Snow falling in April. It’s no secret that the Midwest has harsh winters — but no matter the season, Alliant Energy is committed to delivering reliable, clean energy to our customers. 

Soon, more of that energy will come from the sun. Over the next few years, we are adding nearly 1,100 megawatts (MW) of solar energy in Wisconsin. We also have plans to add 400 MW of solar energy in Iowa. Solar energy is proven to be a reliable and affordable clean energy resource, even during the cold, dark days of winter.  

You might be thinking, “wait a minute, you just said ‘dark days’. Aren’t we talking about energy from the sun?” While yes, the season does present challenges, like less daylight, our solar projects are built with this and several other winter weather misconceptions in mind. 

Can solar panels withstand the extreme cold? 

Solar panels produce heat when generating energy, which keeps the solar panels from freezing when the temperatures drop. So even during the harshest winters, our solar panels will be working efficiently to deliver the energy that keeps your home warm and cozy. 

Will the snow impact the solar panels? 

Snowy weather is no match for our solar panels — in fact, we welcome it. The panels we’re installing at our utility-scale solar projects are “bi-facial”, meaning they can absorb sunlight and generate energy from the front side and back side. When snow accumulates at our solar sites, it acts as a reflector, bouncing the sunlight back up from the ground to the back side of the panels.  

Additionally, most of our solar panels sit on a tracking system, which means they move with the sun during the day. Reaching a maximum angle of approximately 45 degrees, our solar panels will rarely sit horizontally, which makes it difficult for large amounts of snow to accumulate on the panel. Small amounts of snow or ice on the solar panels will melt quickly due to the panel’s ability to absorb heat.  

With so little daylight during winter, is solar energy even worth it? 

Alliant Energy knows that our customers’ energy needs don’t always match up with when the sun is shining, and the solar panels are generating energy – especially in the winter, when the sun is typically down during peak energy usage. 

That’s why we plan to implement battery storage technology. With battery storage, we can store the energy generated during the day and discharge it later when customers need it the most. That way, your energy is still powered by the sun – even if the sun is down.  

As we continue our transition to renewable energy, we’re keeping the needs of our customers at the forefront. Learn more about our plans to deliver reliable, clean energy to our customers by reading our Clean Energy Blueprint.