Researchers at the Oregon State University in the US have ascertained that partial shading provided by solar panels can help in extending the timing of flowers blooming in a field which still brings in pollinating insects as it gives them food later in the season. This, they argue, will be helpful for local farmers and solar developers to maximize the use of available land.
Planting solar arrays with pollen and nectar producing plants creates a habitat for pollinating insects, according to the research. It may be helpful in protecting the declining habitat for pollinating insects due to urbanization, agricultural intensification and land development.
For their research, the team collected data from 48 plant species, 65 different insect species and broke the sites into 3 categories of full share plots under solar panels, partial shade plots under solar panels and full sun plots not under solar panels.
Their research found pollinating insects visited flowers regardless of the presence of solar panels, and that shading from solar panels altered the abundance and timing of floral blooms visited by pollinators and influenced the abundance, richness and diversity of pollinator community. The work recommends planting multiple and shade-tolerant plant species for such solar installations or those that can thrive in full sun. Microclimates with partial shading may provide additional benefits in drylands during hot, dry summers, it added.
"Unused or underutilized lands below solar panels represent an opportunity to augment the expected decline of pollinator habitat," said Faculty Research Assistant at Oregon State and Lead Author of the paper, Maggie Graham. "Near agricultural lands, this also has the potential to benefit the surrounding agricultural community and presents an avenue for future study."
She recommends pollinator habitat at solar PV sites as an option for solar developers, policy makers, agricultural communities and pollinator health advocates if they wish to maximize land-use efficiency, biodiversity and pollination services.
According to the university, this research is the 'first' to look at the impact of solar panels on flowering plants and insects. The US states of Minnesota, North Carolina, Maryland, Vermont and Virginia have developed statewide guidelines and incentives to promote pollinator focused solar installations.
The research team makes these assertions in their work titled Partial shading by solar panels delays bloom, increases floral abundance during the late-season for pollinators in a dryland, agrivoltaic ecosystem, published in the scientific journal Scientific Reports.
In an August 2019 published study, also by Oregon State University, a research team found solar PV panels and agriculture complementing each other, and saw croplands, grasslands and wetlands as best to promote agrivoltaics (see Farmlands Most Productive For Solar Panels, Claims Study).