Solar Farms Shine a Ray of Hope on Bees and Butterflies

A trend of planting wildflowers on solar sites could maintain habitat for disappearing bees and butterflies

By Jodi Helmer 

Image of solar workers standing amidst wild flowers planted under a solar array.

The tidy rows of gleaming solar panels at Pine Gate Renewables facility in southwestern Oregon originally sat amid the squat grasses of a former cattle pasture. But in 2017 the company started sowing the 41-acre site with a colorful riot of native wildflowers. The shift was not merely aesthetic; similar projects at a growing number of solar farms around the country aim to help reverse the worrying declines in bees, butterflies and other key pollinating species observed in recent years.

Up to $577 billion in annual global food production relies on pollination by insects and other animals such as hummingbirds and bats, according to the United Nations. But more than half of native bee species (pdf) in the U.S. have seen their numbers drop sharply since 2005, with almost 25 percent now at risk of extinction. Meanwhile the North American monarch butterfly population has declined 68 percent over the past two decades, the nonprofit Center for Biological Diversity says. Suspected factors include climate change, pesticide use and parasites—along with shrinking habitat, largely blamed on natural landscapes (such as scrublands or wetlands) being converted for agricultural use.

And as pollinator habitat wanes, solar installations are taking up ever more land. The U.S. is expected to convert six million acres of land to such facilities before 2050, according to the National Renewable Energy Laboratory (NREL). Some researchers see this as an opportunity to reclaim land for pollinating species by replacing the usual grass or gravel at these sites with wildflowers that need insects to pollinate them, and that produce the nectar those insects eat. “If we can create some habitat where there wasn’t habitat before, like on solar farms, we can likely have a positive impact,” says Scott McArt, an entomologist at Cornell University.

BOOST TO FARMS AND BUSINESS

When solar developers consider planting pollinator habitat, they also look at the bottom line, notes Lee Walston, an ecologist at Argonne National Laboratory outside Chicago. Despite a higher upfront cost to purchase and plant seed mixes, Walston contends this can actually offer long-term savings. For example, a field of wildflowers requires less mowing and pesticides than conventional grass does. And gravel absorbs heat whereas plants can help keep panels cool, improving energy efficiency.

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