Bees, sheep, crops: Solar developers tout multiple benefits

MONTICELLO (Minnesota) - Silflower was a native plant that covered the vast North American prairie before settlers built cities and farms. The long-stemmed cousin to the sunflower, which is now confined to ditches and roadsides, may soon be making a comeback thanks to solar energy.
Nine solar farms in Minneapolis are home to silflower, which is being grown by researchers to test its potential as an oil-seed crop. This perennial with deep roots provides forage for livestock as well as habitat for bees and butterflies.

Ebony Murrell, a crop scientist at The Land Institute, a non-profit research organization, stated that silflower effects on pollinators can only be measured using a large number of plots. The solar industry is interested to restore pollinator habitat. This partnership seemed like a good fit.

The sun is a renewable energy source which can be used to reduce the use of fossil fuels that emit greenhouse gases. It could also benefit the environment, economy and other areas not well-known.

Critics claim that solar arrays will spread across millions of acres (hectares), thereby wasting farmland as the industry grows. Advocates see potential to diversify crop production, increase landowner income, and repair ecological damage to the ground that has been plowed or paved over.

There are many places where solar can be integrated with innovative uses of land. Brendan O'Neill is an environmental scientist at the University of Michigan who's studying how carbon is stored in Cadillac's new 1,752-panel facility.

Solar installations also house sheep, which reduce the need to mow. Researchers are also exploring the possibility of crop growth under solar panels.


The U.S. Department of Energy funds a search for the best land uses around solar farms. InSPIRE is a project that involves the National Renewable Energy Laboratory, Argonne National Laboratory, and other partners. It's currently being conducted at 25 locations across the country.

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According to the Energy Information Administration, the United States has approximately 2,500 solar operations that are connected to the electric grid. Most of these generate one to five megawatts. For a five-megawatt facility to be operational, it would need 40 acres (16 ha). Although some installations are located on former industrial sites and take up space that was once used for row crops, larger ones often take up space previously used for other purposes.

An analysis by Argonne showed that depending on how fast the country switches to renewable electricity by 2050, more solar land could be required than the combined areas of New Jersey and Massachusetts.

Researchers and solar developers hope that projects with multiple uses for land will reduce opposition from rural residents who don't want their farmland to be destroyed or see solar panels as a nuisance.

We need healthy communities of farmers, but we also require renewable energy, according to Jordan Macknick, InSPIRE's lead analyst on renewable energy labs.


Cascadilla Community Solar Farm, upstate New York: Here, sheep eat grasses between solar panels. While bees and butterflies collect pollen of native flowers at the farm, Cascadilla Community Solar Farm.

Niko Kochendoerfer, a Cornell University researcher, says that initial data from her three year study has shown that light grazing is good for wildflowers and bees. It also keeps plants from being shaded. Rare bee species are starting to emerge.

Kochendoerfer and Lewis Fox, her partner, own about 400 sheep. Farmers can graze their sheep at solar sites for $300 to $550 per annum. This increases farm income and saves them money on renting or buying pasture. She said that grazing is cheaper than traditional site management.

Fox has sheep at the solar sites in southern Pennsylvania and Vermont.

He said that there will be certain times in the year when the sites will look like a butterfly house at a zoo, with butterflies all around.

According to Lexie Hain (director of the American Solar Grazing Association, Fox's business partner), sheep are now eating at solar farms in over 20 states. It is also occurring in Australia, the United Kingdom, Uruguay, and other parts of Europe.


Jack's Solar Farm in Longmont, Colorado is another example of solar and agriculture meeting. The farm's 24 acres, or about 10 hectares, now house 3,276 solar panels. This generates enough power to power approximately 300 homes. They also grow tomatoes, squash and kale, as well as green beans.

Researchers compare vegetables grown under panels at six to eight feet (6-8 m) above the ground with those in open sun. The results were mixed in the recent initial season, but the shaded plants showed a longer growth season.

Owner Byron Kominek stated that we don't need to leave the soils beneath our solar panels in our country uncultivated or to weeds. The panels can be raised slightly to create agricultural jobs and more opportunities for the landowners.

Experts at the University of Arizona's Biosphere II laboratory have found that Agrivoltaics, or growing crops beneath panels, is particularly promising in hot and arid areas. They have also planted peppers and cherry tomatoes beneath them.

According to team findings, these crops often outperform those grown in traditional environments. They also lose less water through evaporation when they are in less direct sunlight. This reduces irrigation demand. The plants also keep the panels cool, which increases performance.

It remains to be seen how widespread such farming will occur, according to Greg Barron-Gafford (a biogeography professor at Arizona). Large-scale agriculture will require mechanized harvesting and planting, which might prove difficult under panels.

Barron-Gafford stated that the majority of farms in the country are small and are either losing money or breaking even. He also suggested that leasing land for solar energy could be a way to generate income while still growing food.


Although commercial prospects for agrivoltaics remain unknown, scientists believe that solar grounds can be used to grow native grasses and flowers that attract pollinators. Many of these species are in danger of extinction.

Maggie Graham, an Oregon State University researcher, reported that bees and other insects visited plants partially or completely shaded by panels. They may also pollinate nearby crops, increasing yields.

A recent Argonne study found that solar sites with native pollinator-friendly vegetation could provide three times more habitat quality than farmland. It found that pollinator-friendly sites have nearly two-thirds the carbon storage potential of traditional farmland, and almost one-fifth less runoff. There would also be 95% less soil erosion.

Because plants for pollinators can be more costly than grass at many locations, some solar developers resist this idea. However, this is offset over time by lower maintenance, according to Reed Richerson chief operating officer at U.S. Solar, a Minneapolis developer.

Walmart is attracted to the cause of saving butterflies and bees by its purchase of power from many pollinator-friendly U.S. Solar installations.

There are more than 12 states that have established standards or guidelines. These guidelines are based on quality such as ground cover diversity and density, and the amount and size of the land involved.

We didn't want to greenwash the process by planting some petunias, clover, and other flowers and then saying, "Theres my pollinator friendly contribution," said Michael Noble, director at Fresh Energy in Minnesota, which helped create the standards.

As global warming and species loss accelerates, more nature-based solar gardens will be needed, stated Rob Davis, spokesperson for Connexus Energy.

He said that three years ago, one of the Minnesota cooperative's solar projects was at risk of being rejected by a suburban planning board. But supporters raised the pollinator benefits as well as their visual appeal.

Davis stated that the technology of solar energy was unfamiliar and foreign to him. However, everyone knows what a meadow looks like.


Tammy Webber reported in Fenton, Michigan. Brittany Peterson, AP video journalist, contributed from Longmont Colorado. Follow @JohnFlesher on Twitter and @twebber02. Follow APs climate coverage at


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