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Dual-use solar farms welcome nature back to the land

Downsville, Wisconsin Dairyland solar farm

The Downsville solar project in Wisconsin is one of 18 pollinator gardens covering almost 250 acres at solar projects in the Dairyland system.

Engie

Most ground-mount solar projects built in the United States are on gravel, turf or dirt.

And therein lies the Catch-22 of solar projects. The draw of solar is its ability to provide clean power that preserves beautiful landscapes that are in danger from coal mines, oil wells and fracking.

But mounting solar on gravel, dirt or turf ruins the natural ecosystem anyway. When solar was first starting, many engineers didn’t think about birds, bees and butterflies and why they are important. Now, businesses, cities and farmers are trying to do better.

"We shouldn’t be using land management practices with renewable energy projects that degrade natural ecosystems, like using gravel under solar panels instead of native plants," said Elysa Hammond, senior vice president of environmental stewardship at Clif Bar. 

The birds and the bees ... and the panels 

Surrounding Clif Bar’s 300,000-foot bakery in Twin Falls, Idaho is a five-acre solar array. Instead of gray stones, brown dirt or a green so neon it looks fake, the panels are surrounded by yellows, pinks and lush natural hazels. The reflective solar panels are nestled in a bed of native flowering plants that support pollinators, conserve water and store carbon in the healthy topsoil. This is the emerging model for ground-mounted solar, one that welcomes nature back to the land. 

Clif Bar honey from bees kept at its solar farm

That nature is vital to the longevity of our non-natural agriculture. The decline in pollinators is on the verge of creating a massive food shortage and supply chain problem for humans. The absence of bees would wipe out soy, coffee, apples, almonds, tomatoes, cacao and many more common crops.

In China, human hands with feathers have replaced bees for pear tree pollination. In the United States, the United States Department of Agriculture awarded over $900,000 in grant money to a "robotic pollination system," i.e. drone pollination, to the Washington State Department of Agriculture.

"I just think the technological solution is so high cost compared to the very affordable solution of just planting more flowers," said Rob Davis, director at the Center for Pollinators in Energy at Fresh Energy.

The extra costs associated with pollinator-friendly solar panels include the original seed and raising the panels from 12 inches to 48 inches off the ground. While some developers hem and haw, Davis confidently referred to these startup expenses as "budget dust."

While Clif’s pollinator-friendly solar array powers its own bakery, BlueWave Solar is connecting independent farms with pollinator-friendly solar projects to revitalize their land.

"We don't regard solar development as permanent conversion," said Drew Pierson, director of sustainability at BlueWave Solar. "Hopefully, the way that we've stewarded that land over time is allowing [the land] to be more productive at the end of the project."

By introducing native, non-profit-earning plants to re-enter the soil while still providing a revenue source for the farmer, the soil has time to heal from decades of single-crop abuse, according to BlueWave.

The solar projects protect the soil if the farmers want to turn it back into farmland later. And then there are the multiple benefits of allowing natural grazers such as sheep and goats onto the land around the panels. Natural grazing practices encourage grass to grow, increase soil health and also avoids mowing.

"When you quantify the costs of mowing a solar project six times a year for 30 years — the gas, the labor and then how many times a mower is going to strike a solar panel," Davis said. "The mower introduces a lot of risk and effort."

We shouldn’t be using land management practices with renewable energy projects that degrade natural ecosystems, like using gravel under solar panels instead of native plants.

Dual-use solar has potential beyond sustainability benefits. According to a United Nations report, transitioning to a more sustainable economy could create 24 million new jobs.

Businesses have found that even on an individual level, its sustainability projects lead to job creation and even to a profit-making product. Clif Bar’s pollinator-friendly solar array on a soy farm in Iowa supports a beekeeper as the bees flit between the flowers under the solar panels to the hive, making honey. That honey is sold for $10 a jar at the Clif Family Farm and Winery under the label "solar-grown honey." 

The grass is greener on the underside 

According to the USDA, the United States in 2018 had almost 900 million acres of farmland. Experts and businesses see a world of possibility for sustainable dual-use solar projects on farms. States such as Massachusetts created subsidies and extra compensation in their renewable energy plans for projects that allow for dual usage.

BlueWave Solar is developing 10 agrivoltaics projects and has completed 135 megawatts of solar projects in Massachusetts. Its arrays directly integrate into the community electricity grid and provide farmers with an alternative revenue stream. Residents and small businesses can subscribe to the community solar project to earn solar credits and decrease their electricity bill

At the University of Arizona, an ongoing research project part of the Department of Energy’s InSPIRE has pulled the solar panels from just 3 feet off the ground higher into the air. Underneath, crops that normally would bake to a crisp in Arizona’s heat are finding new life — chiltepin peppers, jalapeños and cherry tomatoes.

The solar-shaded plants produce two to three times as many fruits because they are spared direct sunlight during the day and the heat is trapped during the cold desert nights.

According to Pierson, solar technology is moving towards panels that will be better suited for dual-use while also collecting more power. Single axis tracker solar panels, as one example, physically tilt and move throughout the day to follow the sun’s rays, collecting between 10 and 20 percent more electricity than a standard solar project. Because of the movement, the panels have to be spaced further apart to avoid shading and collisions, coincidentally providing optimal spacing between the panels for the plants underneath to get sunlight.  

"There's a lot of really natural alignment," he said. "You might need to be a little more strategic and precise about the methods of farming but it actually naturally dovetails with elements of regenerative agriculture which focuses on minimizing land disturbance and promoting diversity."

Editor's note: This article was updated June 11 to remove  the reference to a planned BlueWave dual-use solar farm in Knowlton, Massachusetts.

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