A five-year field study by Argonne and NREL finds that strategic planting of native grasses and flowering plants at solar sites promotes vegetation growth that attracts insect communities #solar #ActOnClimate
Click the link to read the version on the Argonne National Laboratory website (Margaret Hopper):
January 17, 2024
Two solar installations built on farmland rehabilitated with native plants have been restored. Argonne researchers note that pollinators are thriving.
Bumblebees buzz from flower to flower, pausing for a moment under the clear blue Minnesota sky. Birds are singing, and tall grasses are blowing in the breeze. This is not a scene from a nature reserve or national park. It is located between photovoltaic solar panels on rehabilitated farmland.
Researchers at the U.S. Department of Energy’s Argonne National Laboratory and the National Renewable Energy Laboratory wanted to understand the environmental value of solar PV sites planted with native grasses and wildflowers. They studied how vegetation was created and how insect communities would respond to newly created habitats. The five-year field study looked at two solar sites in southern Minnesota operated by Enel Green Power North America. Both sites are built on retired farmland.
Smart land use choices provide multiple benefits
Insect biodiversity has declined globally due to habitat loss, pesticides and climate change. Restoring insect habitats coupled with smart land use changes toward renewable energy development could help reverse the course.
For example, as a carbon-neutral source of electricity, scaling up solar PV is crucial to mitigating climate change. According to the Department of Energy’s Future of Solar Energy study, nearly 10 million acres of land in the United States will be needed for large-scale solar development by 2050 in order to meet grid decarbonization and climate change goals. But some lands are more suitable for solar PV development than others. Disturbed land such as former agricultural fields are ideal locations to hold arrays of solar panels compared to land that has not been disturbed before.
More strategies can be added to this winning combination to support insect conservation. Agrivoltaics is a combination of solar energy production and agricultural and vegetation management practices. One type of agricultural solar energy focuses on creating habitat for insect pollinators and other wildlife that can provide important ecosystem services, such as pollination. Pairing solar facilities on previously disturbed lands with habitat enhancement seems like a logical win-win strategy to address energy and biodiversity challenges. However, to date, there is little field data available to document the feasibility and environmental benefits of this new land use approach.
If you build it, will they come?
The two solar sites studied were planted with native grasses and flowering plants in early 2018. From August 2018 through August 2022, the researchers conducted 358 observational surveys of flowering plants and insect communities. They evaluated changes in plant and insect abundance and diversity with each visit.
“The effort to obtain this data was significant, as we returned to each site four times a summer to record pollinator numbers,” said Heidi Hartmann, director of the Land Resources and Energy Policy Program in Argonne’s Department of Environmental Sciences, and one of the study’s co-authors. Authors. “Over time, we have seen the numbers and types of flowering plants increase as the habitat matures. (ed. focus mine) Measuring the corresponding positive impact of pollinators has been very interesting.
By the end of the field campaign, the team observed increases in all metrics of habitat and biodiversity. There has been an increase in the diversity of native plant species and abundance of flowers. In addition, the team observed increases in the abundance and diversity of native insect pollinators and agriculturally beneficial insects, which included honeybees, native bumblebees, wasps, hornets, hoverflies, other flies, moths, butterflies, and beetles. The types of flowers and flowering plants also increased. Total insect abundance tripled, while native bees showed a 20-fold increase in numbers. The largest insect groups observed were beetles, flies and moths.
In an added benefit, the researchers found that pollinators from the solar sites also visited soybean flowers in neighboring crop fields, providing additional pollination services.
Benefits of solar pollinator habitats
“This research highlights relatively rapid insect community responses to habitat restoration at solar sites,” said Lee Walston, a landscape ecologist at Argonne and an ecologist who was the study’s lead author. “It shows that if properly sited, habitat-friendly solar can be a viable way to protect insect populations and can improve pollination services in nearby agricultural fields.” Walston also serves as Division Chief for Environment, Natural Resources and Managed Systems in Argonne’s Environmental Sciences Division.
The research results point to two important implications for environmentally friendly solar energy. The first is that habitat-friendly solar sites can play an important role in preserving biodiversity. Large amounts of ground-mounted solar are expected to be developed in the future, but if properly located, environmentally friendly solar can offset losses in natural areas to provide biodiversity benefits. Second, green solar sites can help mitigate land use conflicts associated with converting agricultural land for solar energy production. Since nearly 80% of future ground-mounted solar development could take place on farmland, proper siting of environmentally friendly solar on marginal farmland can not only preserve prime farmland, but also make land Major agricultural crops are more productive through pollination services provided by environmentally friendly solar energy.
Overall, more research is needed to understand the feasibility of using habitat-friendly solar energy in different regions and to achieve different ecological goals such as the conservation of target insects or wildlife species.
Funding for the InSPIRE project was provided through DOE’s Office of Energy Efficiency and DOE’s Office of Solar Energy Technologies.