Wisconsin Utility Plans Solar Farm Where It Once Dumped Coal Ash

​It’s not just more Wisconsin homeowners that are putting up solar energy panels — some Wisconsin power companies are too.

A project planned by Alliant Energy near Beloit would be the largest utility-operated solar project in the state, with about 7,600 panels on top of a closed coal-ash landfill.

Geoffrey Underwood, of the South Korea-based Hanwha Corp., discussed the project recently while hiking on top of a gently sloping hillside that’s covered with grass and weeds. The south-facing site in the Town of Beloit sits next to a shuttered coal-fired power plant operated by Alliant. By next year, it might hold 20 acres of sun-tracking solar panels capable of generating about 2 megawatts.

Hanwha is developing the solar installation for Alliant and will sell the power to the utility for the next decade, at least.

Underwood said putting solar above a closed coal ash landfill makes perfect sense.

“Solar projects in general are an excellent re-use for landfill Superfund sites, brown field sites, in that, one, the length of the projects and the long life of these projects in the 20- to 40-year range give the land additional time to settle and cure,” he said. “But also (they) make re-use where it wouldn’t be possible to create a commercial, recreational or other habitats.”

Underwood said on firmer terrain, his company would drive piles into the ground to support the foundations for the solar arrays. But on ground made of ash from the plant nearby, Hanwha will build or cast concrete footings that will only go into the ground a little ways. He said the panels will still be able to withstand high winds and the weight of snow and ice.

Alliant project manager Kim Halvorsen said building on the coal ash landfill should also help with financing the project

“We’re not cutting down a forest, we’re not taking away habita. And also we own the site already, so that further reduces the cost,” he said. “This project is really about how far can we go with solar for the lowest cost per kilowatt hour.”

The hillside is just above the Rock River, with a stormwater retention pond between the river and the landfill. Rock County has already extended shoreland zoning for the company.

Dennis Mack, of the Wisconsin Department of Natural Resources, said it appears the solar panels won’t make the landfill unstable and that any problems could be easily fixed. Unlike other kinds of installations, said Mack, the panels will be on top of the landfill and easily accessible.

Alliant isn’t just developing the 7,600 panel solar farm because it wants to explore the solar market. Under an agreement with the Environmental Protection Agency aimed at reducing air pollution, Alliant has expanded its efforts with alternative fuels.

That said, the company said the 2 megawatt solar farm exceeds the deal with the Obama administration.

These solar panels may appear non-controversial, but elsewhere on Alliant’s Town of Beloit property, there is some dispute: Alliant is looking to expand a natural gas-fired facility and, if state regulators approve that expansion, the company plans to build a second solar farm to help power the natural gas units.

Michael Vickerman, of the group RENEW Wisconsin, said making more solar dependant on use of more fossil fuels is not the way other utilities are going.

“Our view is that solar can stand alone all by itself. It does not need to be put inside a large central station generating facility,” said Vickerman. “Dairyland Power has issued a solicitation looking for 25 megawatts of stand-alone solar. Northern States Power, Xcel Energy is also looking for 25 megawatts of stand-alone solar.”

Vickerman said Alliant’s natural gas expansion in the Town of Beloit may not be approved. While that plays out, the company hopes to get started on the solar farm on the coal ash landfill later this year.