Two solar farms in southern Minnesota have demonstrated that renewable-energy sites can deliver an unexpected environmental benefit. Over five years, researchers observed a dramatic increase in insects living among and around the solar panels.
Total insect abundance approximately tripled, while native bee numbers increased roughly twentyfold. Beetles, flies and moths were among the most commonly recorded groups, and the variety of flowering plants also expanded as the sites matured.
The panels themselves were not attracting insects. The transformation occurred because the land beneath and between the arrays had been planted with native grasses and flowering plants instead of being covered with gravel, maintained as short turf or repeatedly treated with herbicides.
The findings suggest that carefully managed solar developments could generate electricity while restoring habitat in agricultural areas where insects have lost much of their food and shelter.
Researchers Followed the Sites for Five Years
Scientists from Argonne National Laboratory, the National Renewable Energy Laboratory and collaborating organisations studied the Minnesota facilities from 2018 through 2022.
The peer-reviewed research, published in Environmental Research Letters, examined changes in flowering plants, insect abundance, insect diversity and pollinator activity. It also investigated whether insects living inside the solar sites visited crops in neighbouring fields.
The complete study, titled “If You Build It, Will They Come?”, describes the sites as solar-pollinator habitats because grasses, wildflowers and other flowering plants were intentionally established among the photovoltaic arrays.
Researchers repeatedly surveyed the same areas during the growing seasons. As the vegetation became established, flowering-plant richness increased, more insect groups appeared and native bee abundance rose particularly quickly.
The response occurred in fewer than four years, showing that insect communities may return relatively rapidly when suitable habitat is created within an otherwise intensively farmed landscape.
Native Bees Experienced the Most Dramatic Increase
The twentyfold increase in native bees was the study’s most striking result. Native bees differ from managed European honeybees because many live alone, nest in soil or plant material and rely on nearby flowers throughout their active seasons.
A conventional agricultural field may provide abundant food while a crop is flowering, followed by very little nectar or pollen for the rest of the year. A diverse mixture of native plants can provide blooms at different times, creating a more continuous food supply.
Solar sites can also remain relatively undisturbed for decades. Once construction is complete, the ground between the panels may experience less ploughing, harvesting and heavy machinery than surrounding farmland. That stability can give ground-nesting bees and other insects opportunities to reproduce.
The Argonne National Laboratory summary of the Minnesota research reported that flowers and flowering-plant species increased alongside the insects. It also identified beetles, flies and moths as the most numerous insect groups observed during the project.
The Benefits Reached Nearby Soybean Fields
The insects did not remain entirely within the boundaries of the solar farms. Researchers also observed pollinators visiting soybean flowers in adjacent agricultural fields.
Bee visitation near the solar-pollinator habitat was greater than visitation in the interiors of soybean fields and beside roadside areas. It was comparable to visitation near established grasslands enrolled in the federal Conservation Reserve Program.
This matters because solar development is sometimes presented as competing directly with agriculture. The Minnesota results show that the relationship can be more complex. A solar facility may occupy part of an agricultural landscape while providing habitat that supports ecological services beyond its fence.
Soybeans can reproduce without insect pollination, but bee visits may still improve aspects of production under certain conditions. More broadly, pollinator habitat near farms can support insects that visit fruits, vegetables and other crops that depend more heavily on animal pollination.
The U.S. Department of Energy’s explanation of pollinator-friendly solar notes that pollinators contribute to about 35% of global food-crop production. The department has been funding research into how solar arrays, agriculture and habitat conservation can operate on the same land.
Not Every Solar Farm Automatically Helps Wildlife
The Minnesota findings should not be interpreted as evidence that installing panels alone causes biodiversity to increase.
A solar facility covered with gravel, non-native turf or bare soil may offer little food or shelter for insects. Poorly planned development can remove existing habitat, fragment wildlife corridors or disturb sensitive ecosystems during construction.
The positive results came from deliberate habitat restoration. Native grasses and flowering plants were selected, established and managed beneath and between raised rows of panels. The sites were also located in agricultural landscapes where the previous land use offered fewer diverse floral resources.
Vegetation management remains critical after planting. Native seed mixtures can take several seasons to mature, while invasive plants may require control. Mowing schedules must account for flowering periods and insect nesting, and excessive pesticide use can undermine the purpose of creating the habitat.
The outcome therefore depends on where the solar farm is built, what existed there previously and how the land is managed throughout the project’s operating life.
Panels May Create a Useful Microclimate
Solar arrays can change conditions at ground level by producing alternating areas of shade and sunlight. They can affect soil temperature, evaporation and moisture availability, potentially allowing different plant species to occupy different sections of the site.
During hot or dry weather, partial shade may help some vegetation retain moisture. Other plants may perform better in the open strips between panel rows. That variation can produce a more complex habitat than a uniformly managed field.
The effect is not automatically beneficial for every plant or insect. Dense shading may suppress certain species, while panel height, spacing and orientation influence how much sunlight and rainfall reach the ground.
For that reason, pollinator-friendly solar design must consider both electricity production and ecological performance. Sufficient space may be needed for vegetation management, plant growth and access by maintenance teams.
Solar Farms Could Support Dual Land Use
The practice of combining energy generation with agriculture or ecological activity is commonly known as agrivoltaics. Depending on the project, the land beneath solar panels may support crops, livestock grazing or pollinator habitat.
The Department of Energy has estimated that large areas of agricultural land near existing or planned utility-scale solar development could potentially benefit from habitat established within solar facilities. It has also noted that well-designed perennial vegetation may reduce long-term mowing and herbicide requirements.
For solar developers, native vegetation can contribute to soil stability, water infiltration and erosion control. For neighbouring farmers, it may provide habitat for pollinators and other beneficial insects. For local communities, it offers a way to make energy infrastructure contribute more visibly to the surrounding landscape.
These advantages require investment during planning and establishment. Native seeds can cost more than basic grass mixtures, and ecological management may require specialised knowledge. However, longer-term maintenance savings and environmental benefits could offset part of that initial expense.
The Study Has Important Limitations
The results are encouraging, but they do not establish that identical increases will occur at every solar farm.
The research followed two Minnesota facilities, meaning climate, soil, landscape and management conditions were geographically limited. Insect numbers can also vary with rainfall, temperature and seasonal conditions.
Because the project tracked changes as newly planted habitats matured, it demonstrated a strong association between restoration and increasing insect activity. Broader studies across more locations would help determine how consistently the approach works in different regions.
The research nevertheless provides valuable real-world evidence. It did not rely only on models predicting that pollinators might benefit. Researchers repeatedly visited functioning utility-scale solar sites and recorded how the vegetation and insect communities changed over several years.
Clean Energy and Biodiversity Do Not Have to Compete
The unexpected insect boom in Minnesota offers a practical lesson for future solar development. Land beneath photovoltaic panels does not have to become unused industrial space.
When native plants replace heavily disturbed or biologically simple ground cover, solar farms can become pockets of habitat within agricultural landscapes. Those areas may support bees, moths, beetles, flies and butterflies while continuing to produce electricity.
The most important finding is not that solar panels somehow attract insects. It is that the land surrounding energy infrastructure can be designed to serve more than one purpose.
Minnesota’s solar farms produced electricity as expected. With thoughtful vegetation management, they also helped rebuild an insect community far faster than many observers might have anticipated.
