Photos of ground-mounted solar farms often depict shiny panels staked in barren, brown ground. For communities hesitant to accept and support solar, these photos can leave the impression that solar causes damage to land.
“Images of California and desert-sited solar arrays are so common that many people begin to think, what did the PV solar arrays do to the ground?” said Rob Davis, director of the media and innovation lab at Fresh Energy, a Minnesota non-profit dedicated to speeding the transition to a clean energy economy.
But public opinion can improve when communities instead see images of solar farms framed by native flowers and short-growing meadow grasses.
Investing in pollinator-friendly native plants at solar sites benefits multiple stakeholders: installers, environmental advocates and communities. A new voluntary standard signed into Minnesota law in May 2016 was the first of its kind to set a precedent for pollinator-friendly native groundcover at solar farms.
The law says that owners of ground-mounted solar arrays may choose to use pollinator-friendly native plants underneath solar arrays and should use native plant species and seed mixes whenever possible. To claim that the site provides benefits to pollinators, gamebirds and songbirds, the site must follow the guidelines in the Board of Water and Soil Resources’ pollinator plan. The option to make the claim is voluntary, but it’s a good way to get community support for solar farms.
To officially designate a site as pollinator-friendly, installers must fill out a Solar Site Pollinator Habitat Assessment Form that requests information such as “percent of site dominated by wildflowers” and “seasons with at least three blooming species present.” Installers send the completed form to the Minnesota Board of Water & Soil Resources.
Pursuing native plant groundcover means more expenses up front, but less maintenance after establishment. It also comes with a wealth of other benefits.
Native, pollinator-friendly plants help the struggling bee population. Last year, the United States Fish and Wildlife Service listed a bumble bee species as endangered for the first time. A February report on North American and Hawaiian bees by the Center for Biological Diversity found that more than half of native bee species (with sufficient data to assess) are declining. The primary drivers of decline are habitat destruction and pesticide use.
Marla Spivak, PhD, a Minnesota-based entomologist whose TED talk on the importance of bees has been viewed more than 2.2 million times, helped to develop Minnesota’s pollinator plan along with conservation biologist and monarch butterfly expert Karen Oberhauser, PhD.
“It just seemed like such a great win-win, and that both of us as entomologists and conservation biologists would be able to be in a great position to suggest some flowers that could be put under solar sites that would beautify the site aesthetically but would also provide a lot of benefits to farmers,” Spivak said.
Audubon Minnesota supported development of the standard as well, since native vegetation supports hummingbirds and grassland birds that eat insects, like eastern meadowlarks and grasshopper sparrows.
Spivak said native vegetation is one way to make up for the inevitable environmental disturbance that occurs when installing solar farms. She said native plants have multiple, stacked benefits for conservation.
“It has so many benefits, not just to bees, which are directly tied to our food system through pollination services, but also improve soil quality, retention of nutrients and, ultimately, water quality,” Spivak said.
The potential for conservation efforts on solar sites is different from other types of power production plants. If pollinator plants are planted by a fossil fuel power plant, there’s potential for pollution in the soil, which then could harm the bees and other wildlife that pollinate the plant. But the soil under solar arrays would not carry that risk and can be a very nutritious and non-polluted habitat for wildlife.
“It really helps remediate soil, prevent runoff, improve water quality and it helps the productivity on their farm land,” Spivak said.
Healthy soil is especially helpful on farmlands where the next field over may be growing the community’s food.
Commercial solar installer SoCore Energy planted native pollinator plants at about a dozen of its solar sites in Western Wisconsin in the past year. They haven’t begun blooming yet.
“The alternative option that we would plant would be turf grass, and turf grass requires a lot of operations and maintenance,” said Laura Caspari, director of development.
Choosing pollinator plants for solar arrays requires more maintenance in the first three years, but much less after that point. The alternative, turf grass, requires endless mowing. Caspari anticipates pollinator plants will save SoCore O&M money in the long-term, which was motivation enough to pursue this unusual option.
“We were quite impressed when we saw the maintenance cost reduction after the establishment period, so I definitely would encourage people to look at that aspect of it,” Caspari said.
During the first three years, the biggest maintenance concern will be eradicating fast-growing invasive plants. They’ll need to be killed by mowing, herbicide or manual extraction. Once the native plants are established and their roots have grown to the average 10 to 15 ft, they’ll do a good job of crowding out any weeds or invasive plants themselves, with the occasional need for human intervention. Caspari said SoCore carefully selected low-growth plants appropriate for a solar farm, but if anything grew too high they would require trimming.
While the upfront cost of native, pollinator-friendly seeds will be higher than turf grass seeds, the cost of ongoing maintenance will be much lower. Management and maintenance costs of a low-growing native meadow habitat are roughly half that of turf grass mowing and maintenance.
Another benefit of native grasses for contractors is within the permitting process. Installers must obtain permits for storm water runoff that vary state by state. When contractors use turf grass under arrays, the storm water runoff is greater due to the small grass’s small roots not soaking it up. When contractors use native plants instead, less runoff is produced since the root systems are much deeper and better at soaking up the rainwater.
“There’s not only an environmental benefit there, but it makes the permitting process for storm water go more smoothly,” Caspari said.
Forbes reported that siting solar and other renewable energy power projects can be challenging. Although state governments have the final say in whether new power production plants are permitted, local communities carry lots of sway in the debate.
Residents who think solar damages land can put pressure on town councils that can halt renewable energy development. So how can solar advocates win over the locals?
Native plants are one way. Caspari said when SoCore Energy proposes projects without native plants, the community response is less favorable.
“We’ve definitely found a better reception when we come in with a native vegetation and pollinator plan,” Caspari said. “The farming communities do typically understand the benefits of pollinators and the storm water benefits.”
Davis has no doubt native vegetation helps solar contractors get community buy-in. “They know that they can go into these rural communities and talk about agricultural values. And actually have the backup of folks like Marla, saying, ‘Oh yeah, this isn’t just window dressing. This is real acreage that’s going to really benefit pollinators.’”
Integrity is key
When consumer demand for organic food first hit the market, companies were labeling foods as “organic” arbitrarily until the FDA set a standard for the term. Fresh Energy’s Rob Davis wants to make sure companies are being true to their word when they claim a solar site is “pollinator friendly.”
Although Maryland unanimously passed a statewide standard based on Minnesota’s standard, most states do not yet have pollinator-friendly standards. Davis said installers in other states should look to the Minnesota standard if they want to go the pollinator-friendly route. SoCore Energy agrees.
“We’re not talking about just a narrow row of native vegetation by the front gate that makes it look like a project is pollinator-friendly,” Caspari said. “Just putting a row of pretty plants along the front fence doesn’t achieve that. That’s why the Minnesota standard is so important, because it provides a benchmark.”
Davis said pollinator-friendly solar projects are now being proposed and built in Iowa, Maryland, Nebraska, New York, North Dakota, Vermont and Wisconsin.
Taking it to the next level
Connexus, a co-op in Minnesota, earned a perfect score on the Solar Site Pollinator Habitat Assessment. Now it’s taking the conservation commitment a step further: It partnered with local beekeeping company Bolton Bees to set up 15 beehives on its solar farm.
“To us, bee hives at a pollinator-friendly solar garden seem like the natural next step,” said Samantha Neral, Connexus spokesperson, in a press release.
The beekeepers have even created a new name for honey produced from apiaries on or adjacent to a pollinator-friendly solar arrays. It’s called “Solar Honey.”
If more installers take up the pollinator-friendly initiative, the future may look sweeter for bees.