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.

Josh Richardson, of Prairie Restorations Inc., waters Daniel Dehn's milkweed plant at a Connexus Energy event on Wednesday. Prairie Restorations Inc. helped kids plant a variety of pollinator-friendly plants at the event. Evan Frost | MPR News

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.

Native pollinator plants grow in between rows of solar panels at Connexus Energy in Ramsey, Minn. on Wednesday. Evan Frost

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."

Patricia Rosales was there with some of her English language students from Otsego Elementary, who learned about the importance of pollinators in school.

"It's their future, and they know if something happens to bees, what would happen, if we didn't have fruits and vegetables and how the grocery store would look without all the things that are pollinated by bees," Rosales said.

Under a tent next to the Ramsey Renewable Station, Connexus CEO Greg Ridderbusch described the project to a few dozen people — many of them members of the electric cooperative.

From left, Santiago Lopez-Ramos, 8, Daniel Dehn, 7, and Sebastian Lopez-Ramos, 9, plant milkweed and other pollinator-friendly plants at a Connexus Energy event on Wednesday. Evan Frost | MPR News

"We all know we need to get to higher and higher levels of carbon-free electricity on the grid, he said, "so our strategy is, if we can find projects that will both save us money and green the electricity that we're adding to the grid, those are good projects."

Ridderbusch added on sunny days, power from the panels costs less than power from the electricity grid. In addition, the power saved in the batteries helps the co-op rely less on the grid at times when wholesale electricity is most expensive — at peak times, like when everybody gets home from work and school and turns on the air conditioning.

"Over the next 25 years, the plantings that will be here will improve the soil, and it will be a habitat for pollinators — we actually have a farm next door," Ridderbusch said.

That farm grows pumpkins and melons. Those plants, plus the pollinator habitat planted alongside the panels make it a good spot to make honey. Connexus is working with Minneapolis-based Bare Honey, which has placed bee hives on the site.