Minnesota solar farms planted with native habitat see native bees multiply 20-fold

Overview

Updated Oct 26

In 2018, Enel Green Power seeded two retired farm fields in southern Minnesota with native grasses and wildflowers beneath its solar panels. By 2022, native bee numbers had grown 20-fold, total insects had tripled, and flowering plant species had increased sevenfold.

The five-year study, led by Argonne National Laboratory and the National Renewable Energy Laboratory, found insect communities responded within four years of planting. Bee visits to soybeans next to the solar sites ran well above those at field interiors, a finding that drew new attention in August 2026.

Why it matters

Solar is spreading across farm country. Planted with native habitat, those acres can restore insects and boost pollination for adjacent crops.

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Key Indicators

20-fold

Native bee abundance increase

Native bee numbers grew 20-fold over five years at the two solar sites, with most gains after Year 2.

7-fold

Flowering plant species richness increase

Average flowering plant species richness rose sevenfold within the habitat transects.

3-fold

Total insect abundance increase

Total insect abundance tripled, led by beetles, flies, and moths.

2.5x (the 2.5x ratio is kept; a 2026-08-23 Iowa Soybean Research Center article describes the gap as twice as many visits)

Bee visitation at solar-adjacent soybean fields vs. interiors

Bee visits to soybean flowers within 15 meters of solar habitat ran about 2.5 times higher than at field interiors.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Lee Walston

Lead researcher, landscape ecologist at Argonne National Laboratory

Active at Argonne, publishing on solar-pollinator habitat and agrivoltaics

Organizations Involved

Argonne National Laboratory

US Department of Energy national laboratory

Led the five-year field study

Argonne is a US Department of Energy national laboratory that led the solar-pollinator habitat study.

National Renewable Energy Laboratory (NREL)

US Department of Energy national laboratory

Co-led the study

The National Renewable Energy Laboratory co-led the study, contributing expertise on solar site design and land-use trade-offs.

Enel Green Power North America

Renewable energy company

Operated the two solar sites studied

Italian utility Enel's North American renewables arm operates the two southern Minnesota solar facilities where the study was conducted.

Timeline

March 2018 January 2024

5 events Latest: January 2024

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January 2024
Study published in Environmental Research Letters
Latest Publication

Peer-reviewed paper reports that all habitat and biodiversity metrics increased each year, with native bee abundance rising exponentially after Year 2.
January 2024
August 2022
Field campaign concludes
Research

After 358 surveys, researchers document sevenfold increase in flowering plant species, tripled insect abundance, and 20-fold rise in native bees.
August 2022
July 2019
Soybean field pollination surveys start
Research

Researchers begin observing pollinator visitation in nearby soybean fields during July bloom periods, comparing solar-adjacent, CRP-adjacent, roadside, and field interior transects.
July 2019
August 2018
Five-year survey campaign begins
Research

Argonne and NREL researchers begin 358 observational surveys of flowering vegetation and insect communities at both sites.
August 2018
March 2018
Native habitat planted at two Minnesota solar sites
Habitat Restoration

Enel Green Power seeded native grasses and wildflowers at two southern Minnesota solar facilities built on retired farmland.
March 2018

Scenarios

More states pass pollinator-friendly solar laws

Possible Resolves by Q2 2028

Discussed by: Clean energy policy trackers including the NC Clean Energy Technology Center; Minnesota, Michigan, Vermont, Maryland, and Illinois already have certification laws

The study gives state lawmakers a measurable return on pollinator-friendly solar: insect numbers tripling and native bees multiplying 20-fold within five years. The evidence could push additional states, especially in the Midwest where solar is expanding fastest on farmland, to pass certification standards requiring native habitat under new utility-scale arrays.

USDA or DOE launches a dedicated solar-pollinator program

Possible Resolves by Jan 31, 2028

Discussed by: The study itself, which frames the spillover effect as a food-security benefit; Argonne's own coverage highlights the soybean pollination findings

The 'spillover' result is the policy hook: bee visitation at soybean fields adjacent to solar habitat matched Conservation Reserve Program grasslands and ran 2.5 times higher than field interiors. That gives federal agencies an argument that pollinator-friendly solar supports crop production. A dedicated program would surface in USDA or DOE funding announcements rather than as a budget line item.

Solar industry adopts pollinator habitat as default design

Unlikely Resolves by End of 2028

Discussed by: Trade organizations like the Solar Energy Industries Association (SEIA), which track land-use practices and community acceptance of utility-scale projects

Solar developers face local opposition on farmland, and pollinator habitat converts the 'solar sprawl' objection into an environmental benefit. If SEIA or a top developer formally commits to native plantings as standard design on new utility-scale projects, the practice becomes the default without legislation. That outcome is the least certain because it depends on voluntary adoption and landowner cooperation.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

1985–present

Conservation Reserve Program (1985–present)

The 1985 Farm Bill created the Conservation Reserve Program, paying farmers to convert erodible cropland back to grass. It became the largest private-lands conservation program in the US, covering tens of millions of acres at its peak.

Then

Millions of acres of cropland returned to grassland, reversing erosion and creating wildlife habitat across the Great Plains and Midwest.

Now

CRP grassland became the de facto benchmark for farmland habitat quality. The Minnesota study used CRP-adjacent soybean fields as its comparison for pollinator visitation.

Why this matters now

Solar-pollinator habitat matched CRP grassland for bee visitation in this study. That means solar arrays on farmland can slot into the same conservation framework as the country's largest habitat program.

2010s

Monarch decline and the pollinator crisis (2010s)

Monarch butterfly populations fell sharply in the 2010s as milkweed disappeared from farm country, and conservation groups petitioned the federal government to list them as endangered. States responded with voluntary monarch protection plans, and researchers targeted agricultural land as potential habitat.

Then

The US Fish and Wildlife Service launched a monarch conservation fund, and states from Minnesota to Texas developed voluntary habitat plans.

Now

The crisis normalized the idea that working agricultural land can double as habitat, opening the door for solar arrays to be designed as pollinator habitat.

Why this matters now

The Minnesota study demonstrates a concrete mechanism for offsetting farmland habitat loss: instead of bare gravel under panels, native plantings that support bees, butterflies, beetles, and flies.

1992–present

Tallgrass prairie restoration at Neal Smith National Wildlife Refuge (1992–present)

The US Fish and Wildlife Service began restoring thousands of acres of tallgrass prairie on former Iowa farmland at Neal Smith refuge. It was slow, deliberate work: careful seed mixes, repeated planting, and decades of prescribed burning and weed control.

Then

The refuge rebuilt a functioning tallgrass prairie ecosystem on retired cropland, demonstrating restoration is feasible on degraded agricultural soil.

Now

Prairie restoration projects established the techniques and timelines for rebuilding native grassland, including the seed mixes used at solar sites today.

Why this matters now

The Minnesota study shows insect communities responded within four years of planting, far faster than full ecosystem recovery. Solar projects, with their multi-decade lifespans, can host restoration that keeps compounding.