Wind, solar impacts on rural land

WASHINGTON — Solar and wind farms have become a regular part of the rural landscape and a new report documents the impact the energy sources have on farmland.

The U.S. Department of Agriculture’s Economic Research Service issued a report May 21 that examines land cover and land cover change associated with utility-scale solar and wind development in rural areas from 2009 to 2020.

Widespread expansion of utility-scale renewable energy development in the United States began with growth in the wind energy sector in the 1990s, followed by solar in the mid-2000s.

In 2020, wind-generated electricity was the second largest source of renewable energy after hydropower, comprising 8.4% of total electricity generation. Solar power was third with 2.3%, according to the U.S. Energy Information Administration.

Utility-scale solar and wind projects were located predominantly in rural areas and often on lands used for crop production or animal grazing.

As of 2020, 99.8% of utility-scale wind turbines and 74% of utility-scale solar installations were in rural areas.

“Although there is less solar than wind capacity, solar is growing at a faster rate and is expected to comprise nearly three-quarters of the growth in renewable generation beginning in 2025,” according to the report.

“Further, policies, including the Inflation Reduction Act of 2022, are expected to lead to a more rapid expansion of solar and wind development.

“Despite the growth in solar and wind projects, the cumulative amount of land in rural areas that is directly affected by the development is small relative to the amount of farmland. Still, rural landscape changes and the socioeconomic effects in local communities from nearby solar and wind development may be substantial in some areas.

“After installation, solar sites more commonly changed land cover than wind, including shifts away from agriculture. Wind sites maintained agricultural land cover. This suggests that wind is compatible with agriculture and that land-use competition exists between farmland and solar farms.”

Footprint

In 2020, the estimated footprint of solar farms was approximately 336,000 acres; the footprint of wind farms was approximately 88,000 acres.

For comparison, there were approximately 897 million acres of land in farms in 2020, so the estimated footprint of solar and wind combined was approximately 0.05% of farmland acres, according USDA’s National Agricultural Statistics Service.

Nearly 80% of the estimated footprint in rural areas was from solar projects, which provided 27% of the capacity.

This footprint does not capture additional physical structures, including transmission lines, which are required to transport the generated electricity.

Typically, a wind farm is spread over a much larger land area than a solar farm. Wind turbines must be spaced apart to maximize wind flow.

However, estimates suggest that 96% to 99% of the land in a wind farm does not contain any permanent physical structures.

The direct land cover impact of a wind farm is limited to the relatively small area on which service roads, turbine pads and other infrastructure are constructed.

Alternative land uses, such as farming or ranching, are typically maintained on the land within the wind farm.

In solar projects, spacing between panels is limited, and the land cover in the area beneath the solar panels is removed prior to development, leaving bare soil on which the solar panels are constructed.

While solar farms tend to be smaller than wind farms, the direct land cover impact of a solar farm — the area beneath solar panels and other infrastructure — typically extends throughout a larger portion of the solar farm.

Data Details

Here are some other findings.

• 43% of solar farms were installed on land that was in cropland and 21% were installed on land that was pasture-rangeland prior to development.

• Wind turbines were predominantly installed on land that was classified as cropland, at 56%, and pasture-rangeland, at 36%.

• Solar projects were more commonly installed on nonagricultural land, at 17%, than wind turbines, at 3%.

• In the Midwest, 66% of solar farm sites were characterized as cropland prior to installation. In the Plains and the West, most solar sites were pasture-rangeland, at 60% and 51%, respectively.

• 93% of wind turbine sites in the Midwest were classified as cropland prior to installation. In the Plains, 45% of turbine sites were pasture-rangeland, and in the West, 65%.

• Land cover changed at 26% of solar sites, but only 5% of wind sites; 15% of solar sites shifted out of agriculture after installation; for wind, it was less than 1%.

• Typically, solar sites that were categorized as cropland prior to installation remained in the same land cover category after installation, at 82%. For wind turbines, the share was 99%.

• 73% of solar sites and 92% of wind turbine sites that were categorized as pasture-range prior to development maintained the same land cover category after development.

• For sites categorized as continuous cropland prior to installation, a higher share of solar sites, at 36%, was fallow, or uncultivated, in at least one of the three years after installation, compared to wind’s 7%.