Illuminate Home
Drone photo of worker walking through Kohler Solar Field in Kohler, Wisconsin.

Solar in the summer: Does more daylight mean more energy generation?

As summer heat increases, so does electricity use. Air conditioners work hard to cool homes and businesses to allow us to live and work comfortably.

On really warm days, when everyone needs electricity at the same time, this can strain the energy grid. Luckily, the time of peak demand generally coincides with peak solar energy production. That allows us and other utilities to provide the reliable service customers expect.

Sunlight is available for longer periods of time in the summer. From the winter solstice (December 21) to the summer solstice (June 21), the sun shines a few additional minutes each day.

Wisconsin and Iowa will see between 15 and 15.5 hours of sunlight on June 21 this year. That means a solar project can generate about three and a half times more electricity in June or July than in December.


The average kilowatt-hours generated by a solar energy project (vertical axis) by time of day (horizontal axis).

As we continue to put more solar energy on the grid, with 250 megawatts (MW) already and nearly 600 more we expect to be in service by the end of the year, we’ll see big benefits of longer days and more sunshine.

All the electricity we generate from the sun is zero-fuel-cost energy, and it helps us avoid running our fossil-fuel facilities for longer periods of time. The bottom line: It all adds up to savings that we pass on directly to our customers.

And this is just part of why we’re so excited about the progress we’re making in solar energy. Check out additional information through our Iowa and Wisconsin Clean Energy Blueprints.

Chris is a Communications Partner specializing in Alliant Energy’s renewable investments. Coming from a journalism background, he’s excited to tell the story of Alliant Energy’s Clean Energy Blueprint and other renewable trends in new and exciting ways.

Recent Stories