A victory for clean energy and biodiversity

Lee Walston (left) a landscape ecologist, with students during a plant survey at the Ramsey Renewable Station in Ramsey, Minnesota. — ©2024 The New York Times Company

IT’s not your average solar farm. Amid the meadow of wildflowers swaying in the breeze, bursts of purple, pink, yellow and white scatter through the landscape beneath shimmering glass panels.

Insects, bees and butterflies like the monarch flutter among the blossoms.

As dragonflies zip past and birds chirp, this solar farm in Ramsey, Minnesota, stands out for more than just producing clean energy – it also addresses another pressing issue: biodiversity loss.

Solar farms have increasingly spread across the United States, covering vast areas to meet the growing demand for renewable energy.

Yet as these projects expand, they take up land once home to wildlife.

In response, scientists, environmentalists and solar developers are working together to reimagine solar farms as both energy producers and habitat for pollinators like bees and butterflies, which play an essential role in maintaining ecosystems.

As solar farms cover more land in the coming decades, they have the potential to be part of the solution to both climate change and ecological decline.

Addressing dual challenges

“We have to address both challenges at the same exact time,” said Rebecca Hernandez, an ecology professor at the University of California, Davis.

As solar farms multiply, they also occupy land that insects and other wildlife depend on for survival. This loss of habitat is a significant contributor to the global biodiversity crisis, particularly for pollinators.

Insects, which pollinate crops and provide food for other wildlife, are facing alarming declines.

Pollinator-friendly solar farms are part of a growing strategy to combat this issue.

By incorporating native plants beneath and around solar panels, these farms can offer insects food and shelter. These plants can also help reduce erosion, nourish the soil, and even store carbon. For nearby farmers, the increase in pollinators can improve crop yields, making it a win-win.

Pollinator habitat

However, not all solar projects are created equal when it comes to supporting biodiversity.

Scott Black, executive director of the Xerces Society for Invertebrate Conservation, notes that some solar projects are only making minimal efforts to create pollinator habitats.

“It’s not fair if some people are truly stepping up to do this right and another company is barely doing anything and saying they’re pollinator-friendly,” he said.

Many solar farms limit pollinator-friendly vegetation to small corners of the site, providing little ecological value. This has led to accusations of greenwashing – misleading claims about the environmental benefits of a project.

Certification efforts are under way to bring more transparency.

Black’s organisation is working on a programme to certify solar sites for their ecological value.

However, much of the solar industry is still figuring out how to balance the need for renewable energy with the need to preserve biodiversity.

‘If you build it, will they come?’

At the Ramsey solar farm, biologists are conducting research to understand how effectively solar farms can support pollinators.

Lee Walston, a landscape ecologist from Argonne National Laboratory, has been studying insect populations at solar farms throughout the Midwest since 2017.

On a recent morning, he led students through knee-high plants at the 7.2ha site, counting bees, moths, and other insects.

“If you build it, will they come?” Walston asks in his research.

The answer, so far, is yes – if the right plants are grown.

In a study published last year, Walston’s team found that insect abundance tripled over five years at two Minnesota solar farms. The abundance of native bees grew 20-fold.

This is especially significant at a time when many insect species, including monarch butterflies and North American birds, are in steep decline.

Acoustic monitoring at the Ramsey site has identified 73 bird species, many of which were likely attracted by the seeds and insects the plants provide. Some even build nests in the structures supporting the solar panels.

Larger mammals, such as foxes, have been spotted on trail cameras, although creating wildlife-friendly solar farms for large animals remains a challenge for developers.

Pollinator-friendly solar

In Minnesota, the success of pollinator-friendly solar farms has sparked interest from developers.

The key to success at the Ramsey site is the height of the solar panels, which allows for taller and more diverse plant species to grow underneath.

This increases the site’s ecological value while reducing long-term maintenance costs.

“We’ve calculated and ran the numbers, and there’s significant savings,” said John Gantner, director of engineering at Engie, the company that developed the Ramsey site.

The investment in taller panels and native plants was “insignificant to the overall project cost”, he said, and over time, the company saves money by needing to mow less frequently.

However, many large-scale solar projects are not following this model.

The upfront costs of taller panels and native vegetation can be prohibitive for utility-scale solar farms with tight profit margins.

This limits the ecological potential of these projects, with many developers opting for lower-growing plants like clover, which offer some benefit to pollinators but are far less valuable than a mix of native species.

Striking a balance for the future

As solar energy continues to expand, finding ways to protect biodiversity while meeting energy demands will be critical.

“On one side, we want to protect biodiversity and pollinators.

On the other side, we need the most efficient way to get kilowatt-hours to customers,” said Jessica Fox, a conservation biologist working on the new certification.

By incorporating native plants and improving standards, solar farms could become a vital tool in addressing two of the most pressing environmental challenges: climate change and habitat loss. — ©2024 The New York Times Company