The Planet Needs Solar Power. Can We Build It Without Harming Nature?

For pronghorn, those antelope-like creatures of the American West, this grassland north of Flagstaff is prime habitat. It gives the animals the food and conditions they need to survive fall and winter.

But for a nation racing to adopt renewable energy, the land is prime for something else: solar panels. The sun shines strong, the terrain is flat and high-voltage transmission lines are already in place from a decommissioned coal plant. Energy collected here could speed to major metropolitan regions across the West, part of a colossal wave of clean power needed to stave off the worst effects of global warming.

Animals need humans to solve climate change. But they also need places to live. Loss of habitat is the top driver of a staggering global decline in biodiversity, the variety of life on earth. The boom in solar, set to be the fastest-growing energy source in the United States, is predicted to fence off millions of acres across the nation, blanketing them in rows of glassy squares.

The good news for wildlife is that there are ways for solar developers to make installations less harmful and even beneficial for many species, like fences that let some animals pass, wildlife corridors, native plants that nurture pollinators, and more.

But at this pivotal moment, as solar farms sprout across the country, those measures often go unused. Among the reasons: a patchwork of local and state regulations governing large-scale solar, not enough research on how animals interact with it, and an absence of federal guidelines on siting or design.

“We’re faced with two truths: We have a climate change crisis, but we also have a biodiversity crisis,” said Meaghan Gade, a program manager at the Association of Fish & Wildlife Agencies. “We have to be mindful that there’s wildlife that are dependent on these habitats, and we have to be smart and thoughtful about how we’re doing this deployment so that we can hold both of those crises at the same time.”

Eighty percent of states rely on voluntary approaches to minimize impacts to species and habitat, according to the association. As developers race ahead, the decisions they make today will reverberate for decades.

On the grassland north of Flagstaff, a ranching family, solar developers and state wildlife biologists have come together to try out solutions on the fly. One sunny day last fall, a helicopter descended over a herd of pronghorn streaking across shrubby grasslands near the site of a planned solar farm.

Pronghorn are exceptional for their combination of speed and endurance. If there was a global mammal marathon, a pronghorn would probably win.

Even though they look like antelopes, they’re more closely related to giraffes. While Arizona’s pronghorn population is stable, it’s a small fraction of the species’ historic numbers.

A net shot from the helicopter, a buck fell and a wrangler jumped out. He tied the buck’s feet and a biologist blindfolded the heaving animal, hoping to calm him. Monitoring his temperature for signs of dangerous distress, they worked quickly to attach a tag to his ear and a GPS collar around his neck.

The collar will track how he responds to the solar farm, which will be broken up into sections. Fifteen corridors ranging from a quarter-mile to more than a half-mile will offer habitat and passage for pronghorn, mule deer and elk.

A moment later the pronghorn galloped away, an unknowing participant in an experiment in coexistence.

‘There’s Always Competing Interests Out There.’

On the surface, the most wildlife-friendly practice might seem obvious.

“If you start with a site that has really no conservation value — it’s cleared, it’s degraded, whatever — then everything you do at that point is a win,” said Liz Kalies, an ecologist who studies clean energy for the Nature Conservancy and works in North Carolina, where forests have been felled to make way for solar.

Pollinators like bees, for example, can benefit from solar facilities that replace crops treated with pesticides, especially when the new installations include native species (nearby crops can benefit, too). In Kentucky, a solar farm is going up at the site of a former coal mine.

But for developers, it’s not so easy. Getting permits and financing for work on former industrial sites can be tricky because of risks like leftover toxic waste. Rural communities sometimes oppose the conversion of agricultural areas to solar, arguing that arable land should be protected for food security and to maintain the economic health of farming towns.

And critically, developers need to be able to move the electricity, which makes the availability of transmission infrastructure paramount to any site.

“While it would be nice to think that there’s all of these low-conflict areas that developers could just go build on and everybody would leave them alone, in reality that’s not how things work,” said Tom Vinson, vice president of policy and regulatory affairs at the American Clean Power Association, which represents utility-scale solar developers. “There’s always competing interests out there.”

Potential solar sites are so ecologically varied that federal guidelines on wildlife and habitat wouldn’t be appropriate, he said. And solar developers already take precautions for animals and plants that are protected under the Endangered Species Act, the intensive care unit for wildlife.

Permeable Fences Make Good Neighbors

All kinds of energy development exact a toll on all kinds of plants and animals.

Oil and natural gas reduce habitat and can cause pollution, including catastrophic spills. They also drive climate change, which is expected to replace habitat loss as the leading threat to the world’s biodiversity in future decades.

Wind turbines come with bird and bat collisions, though many of those deaths can be minimized, and the infrastructure doesn’t take up much space. Anecdotes abound of elk and pronghorn strolling around turbines or napping in their shade.

Solar farms need a lot more land per unit of energy. While they’re projected to take up a tiny fraction of the area dedicated to agriculture, they come on top of that, and on top of land occupied by cities, towns, roads and all kinds of industries.

Up to a third of potential solar development in the United States could overlap with areas that have high value for wildlife movement, according to one study, as animals move to adapt to climate change. (Rooftop and other small-scale solar can go a long way to taking pressure off big installations, but U.S. energy demand would still require a surge in large-scale projects.)

One way to reduce solar’s damage is wildlife-friendly fencing.

National electricity codes require fencing to protect people from electrical hazards and infrastructure from damage. Simply replacing the conventional chain-link version with fencing that has wider gaps will let creatures like foxes scamper through. Raising the bottom of a fence off the ground, to offer a few inches of passage, accomplishes the same thing.

In Florida, a combination of four- and six-foot fencing allows panthers and deer to jump into many of Florida Power and Light’s solar facilities, said Jack Eble, a company spokesman. Wooden supports that shore up fences let medium-sized animals crawl over, and larger openings at the bottom give access to small animals.

“We have not experienced any issues with wildlife damaging solar panels or other solar-related infrastructure to date,” Mr. Eble said.

But so far, wildlife friendly fencing is not commonly used, according to Josh Ennen, a senior scientist at the Renewable Energy Wildlife Institute, a nonprofit collaboration that seeks to find solutions to wildlife conflicts and is mostly funded by industry.

Developers are often unfamiliar with the options for wildlife-friendly fencing, and it may not be easily available. Furthermore, many worry it will backfire if federally protected animals use the permeable fencing to wander onto the site. Suddenly, developers would have to worry about fines for driving over, say, a baby desert tortoise.

Regulations can get in the way, too. Around the country, solar facilities are subject to a disparate patchwork of local and state rules, some of which require specific kinds of fencing.

These challenges need to be solved quickly, biologists and wildlife advocates say.

“It’s not something we can easily retrofit,” Dr. Kalies said. “Developers don’t want to tear down a fence once it’s up.”

A Trade-Off for the Future

At Babbitt Ranches, the solar farm’s fencing will be raised off the ground for smaller animals like rabbits. Pronghorn, mule deer and elk will be kept out because of the developer’s concerns that they could damage equipment or hurt themselves. For those animals, they’re planning the corridors.

Long known for Hereford cattle and quarter horses, Babbitt Ranches stretches over 700,000 acres of private and leased public land. Transmission lines have drawn a crowd of clean energy developers, and the first wind turbines have already gone up.

Clenera, a solar developer, approached the ranch in 2018. For Babbitt’s president, Bill Cordasco, the idea of a large solar project was appealing both financially and morally. It would bring in revenue for the family business while helping reduce climate risks for future generations. But he knew the pronghorn relied on that land. Mr. Cordasco wanted to find a solution that would meet everyone’s needs, including the pronghorn.

“If you guys aren’t interested in working through this pronghorn deal, it ain’t going to happen,” he recalled telling Clenera during their first in-person meeting.

Clenera was interested.

State wildlife officials already had data from earlier GPS collaring, so they knew how pronghorn and mule deer moved through the area. A renewable energy ordinance passed by Coconino County gave additional teeth to the importance of maintaining wildlife linkages in solar facilities.

A back-and-forth over the site design led to adding migration corridors and closing off some dead-end areas where animals could have gotten trapped or disoriented. Developers and wildlife officials discussed the pros and cons of quarter-mile versus half-mile corridors. (Would the smaller ones be wide enough for the animals to use? Would the larger be worth a significant increase in the overall footprint?) In the end, everyone agreed on the range of different corridors, creating a kind of natural experiment.

The miles of additional high-voltage cable and the extra fencing required to break big sections of solar panels into smaller ones make the project more expensive, Clenera officials said, though they declined to say how much. Mr. Cordasco also asked them to help fund long-term studies on the impact of the solar farm on wildlife migration.

“It’s a lot of money,” said Tom Fitzgerald, vice president of development at Clenera. “That’s also the cost of getting all of the stakeholders to get behind you and to support your project, and to pay to be a contributing member of any community.”

Jeff Gagnon, a biologist with the Arizona Game and Fish Department who oversaw the collaring effort, was thrilled to have his agency’s advice taken seriously. He focuses on habitat connectivity, and while dozens of solar projects have come to his agency for review, he said, developers often disregard or minimize their recommendations.

“They can take it or leave it,” he said.

This time, he pointed out, Mr. Cordasco made sure things went differently.

Mr. Cordasco knows the pronghorn he loves could be negatively affected, but he believes the damage will be minimized and the trade-off will be worth it for generations of people and wildlife to come.

“When you make these bigger decisions,” Mr. Cordasco said, “you have to have a very long-term view.”