Alliant Energy has installed a battery station in Decorah to store solar power generated in a neighborhood where several customers have solar panels that produce excess energy. Todd Olinsky-Paul of the Clean Energy States Alliance was in Decorah today for a ceremonial ribbon cutting.

“In terms of physical size, it looks like basically a couple of shipping containers with some other metal boxes mounted around it on pads of the kind your see in substations,” he told Radio Iowa.

The unit will store enough power being generated by nearby Alliant customers with solar panels to provide electricity to about 2000 homes for over an hour.

“The reason that it’s here is because of the high number of solar panels in this area. This is saving money because it’s a lot cheaper than rebuilding the local grid,” Olinsky-Paul said.

The Decorah customers with solar panels are all on the same circuit, according to Alliant Energy, and the utility’s president said the project fits with the company’s goal to expand its use of clean energy. An official from the US Department of Energy said what’s happening in Decorah will become “a model” for the rest of the country. The agency provided $250,000 and state officials awarded Alliant a $200,000 grant for the project.

Olinsky-Paul said the key is that the battery absorbs solar power generated at midday and distributes it in the evening when the sun is setting — and electric demand rises.

“You can’t turn the sun on and off with a switch the way you can with a fossil fuel generator,” Olinsky-Paul said. “…Energy storage added to solar makes the solar more dispatchable and thereby increases its value to the customers, to the utility, to the grid.”

Alliant’s battery installation in Decorah will be a research site, too, for contractors from the US Department of Energy as well as from Iowa State University’s Electric Power Research Center. Alliant has been operating two other battery units, storing energy from its solar garden in Marshallown and from customers near Wellman.