By Elizabeth Dunbar

MPR News/90.1 FM

The environmental benefits of Connexus Energy’s solar-plus-storage project are obvious enough, but this time of year, you’ll notice something more: prairie grasses and flowers planted under and around the sea of solar panels.

Pollinator-friendly plantings at large solar energy sites have become common in Minnesota in recent years. Not only do they provide habitat for the bee and butterfly populations people have been concerned about, but they also promote soil health and probably even boost the solar panels’ electricity output on warm days.

The National Renewable Energy Lab is using the Ramsey Renewable Station and a couple dozen other sites around the country to test that.

“Their hypothesis is that thicker vegetation under and around solar panels creates a cooler microclimate, which actually generates more electricity from the panels,” said Rob Davis, who directs the Center for Pollinators in Energy at the Minnesota advocacy group Fresh Energy.

The group has promoted pollinator plantings at solar sites for several years. It’s now become mainstream, with the state’s largest utility, Xcel Energy, saying it will require solar developers to include plans for plantings at proposed sites. The practice is common in the U.K., and Connexus was the first to try it in Minnesota with a small solar array at its headquarters in 2014, Davis said.

The project would have been covered with gravel, but Connexus staff intervened. In the years since the pollinator habitat was planted there, pictures of the site has been featured in publications such as National Geographic and Martha Stewart Living, Davis said.

Recently, researchers have found bee and butterfly populations are declining — a trend linked to disease, parasites, decreased biodiversity, agricultural practices such as row-cropping and pesticide use, and climate change.

In some parts of the world, the problem is so serious that work crews pollinate crops by hand.

“There’s so many pollinator-dependent crops that we all love and enjoy — blueberries and apples — but every single apple flower needs to be visited two to three times by a bee,” Davis said.

During a Connexus Energy open house on Wednesday, adults and kids planted milkweed along the fence line at the new solar-plus-storage facility in Ramsey.

“It’s neat to hear that the land is good for more than just the solar panels,” said Michelle Austin-Dehn, of Ramsey, who brought her two sons to the event in the family’s electric car. Last year, she said, the kids grew milkweed and collected caterpillars. They also compost and try to use environmentally friendly products.

“It’s important,” she said. “It’s one big planet and we’re all connected.”