Does solar power make sense in Southern Wisconsin?

From homes to businesses and even schools, southern Wisconsin is in the midst of a palpable power shift.

Solar power is getting its time in the sunlight.

“It’s growing at about 30 percent per year,” explained Greg Nemet, professor of public affairs at the University of Wisconsin-Madison. “There are studies that say solar could be 50 percent of our electricity within 10, 15 or 20 years.”

Nemet has been studying solar energy for 20 years. He says the reason for the spike in demand for solar is that costs keep coming down.

“In the last couple of years, people are starting to install solar because it is a cheap way of producing electricity,” Nemet said.

Madison Mayor Satya Rhodes-Conway agrees.

“The economics of solar make sense to almost anyone,” Rhodes-Conway said.

Madison officials plan to install one megawatt worth of solar panels on city facilities by next year. They’re also working with MG&E to purchase five megawatts of power from a local solar farm that will meet about 20 percent of the city’s electricity load.

For Rhodes-Conway, investing in solar isn’t just about economics. It’s about environmental impact, too.

“Everything that we can do at the city level and here in Madison is important. Solar is a huge part of reducing emissions.”

Madison, however, can often suffer from a lack of sunshine. For reference, from January through September of 2019, less than one out of every five days featured clear skies.

Nemet says southern Wisconsin already comes into the fight with a costly disadvantage.

“Just because we’re living farther north and in a cloudy place, solar is twice as expensive here compared to Phoenix, Arizona or some other sunny place.”

“On a cloudy day, you already have less than half of the electricity that you’d have on a sunny day,” Nemet added.

Some are concerned that the recent cloudy trend will continue in Madison in the future.

Jonathan Martin, meteorology professor at the University of Wisconsin-Madison, said a warmer world due to climate change will definitely mean more water vapor will be available in the atmosphere. This will translate to more frequent heavy rain events across southern Wisconsin. However, it’s unclear what that will mean for sky conditions.

“That’s a big question right now in climate science: what will the role of clouds be?” Martin said.

“We don’t really know yet, in terms of cloudiness, what we’ll get in the future,” Nemet added.

Nemet said while he’s keeping an eye on climate trends, he doesn’t view the potential for more cloudy days as a big risk. However, a sudden change in sky conditions-because of a thundercloud, for example-is a different story, and can have a major impact on energy output.

“If you have a big solar farm, and say a thundercloud in five-10 minutes covers it up, and the output goes from 100% to 25%, all of a sudden that’s 100 megawatts of electricity that you don’t have that needs to be made up elsewhere,” Nemet explained.

While it’s manageable, Nemet said the grid needs to deal with changes in power output due to Mother Nature more effectively than it does now.

Despite these challenges, experts say solar is here to stay in southern Wisconsin. With dozens of projects either already online or in the pipeline, southern Wisconsin will be chasing the sun for years to come.

“Solar is for real now and … people are installing solar because it’s the cheapest way to make electricity, even in a place like Wisconsin. I would expect to see more of that.”

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