Inside Clean Energy: Yes, There Are Benefits of Growing Broccoli Beneath Solar Panels

New research shows that the shade from solar panels leads to a brighter green color for broccoli crops, reduced evaporation and increased income for farmers.

National Renewable Energy Laboratory researcher Jordan Macknick carries a tray of seedlings for crops being planted at a testing site in Colorado, part of a study on growing plants alongside solar panels. Credit: Werner Slocum / NREL
National Renewable Energy Laboratory researcher Jordan Macknick carries a tray of seedlings for crops being planted at a testing site in Colorado, part of a study on growing plants alongside solar panels. Credit: Werner Slocum / NREL

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Despite being “yucky” according to some picky eaters, broccoli is well-suited to grow alongside solar panels, according to a new study.

The research from Chonnam National University in South Korea is part of the growing field of “agrivoltaics,” in which agronomists and energy experts look for opportunities for solar power and agriculture to exist on the same land in an effort to meet the world’s needs for both energy and food.

The findings, published in the journal Agronomy, show that shade provided by solar panels helps to make broccoli a deeper shade of green, which makes the vegetable more appealing for grocery stores and consumers without a significant loss of the crop’s size or nutritional value.

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But the greatest financial benefits for farmers come from producing energy. Income from solar was about 10 times the income from broccoli, which indicates that farmers already growing the vegetable are missing out on an opportunity by not having solar panels in the same fields, according to the study. The authors include Kang Mo-Ku, a horticulture professor.

The paper is “a great case study,” said Jordan Macknick, a lead analyst at the National Renewable Energy Laboratory in Colorado, whose work deals with agrivoltaics.

His main caveat is that the results only apply to one crop being grown in one region. He said the paper provides evidence that should encourage additional research in other places and with other crops.

He would know. His team at NREL has several projects involving solar alongside carrots, chard, kale, peppers and tomatoes, among others.

One of the problems with agrivoltaics may simply be the term “agrivoltaics,” which can sound off-putting to some people, especially those who aren’t energy researchers or in energy industries.

Macknick hears this a lot.

“It sounds sort of jargony, and it sounds a little intimidating,” he said. “And, Microsoft Word doesn’t recognize the spelling of it or think it’s a real word.”

But the underlying concept—that farms can produce energy and food on the same acres, as opposed to having to choose one or the other—is vital for the transition to clean energy, he said. 

So far, combining solar and agriculture has worked best with solar arrays of just a few acres, with the electricity mostly consumed by the farm. It doesn’t yet make sense economically in super-sized projects that take up hundreds or thousands of acres.

Researchers are looking at ways to expand the crops that can be grown with solar, and the scale on which solar and agriculture can coexist.

But those efforts won’t matter much unless researchers can sell farmers on the merits of solar and crops working together. And that could be a tough sell. For example, maneuvering farm equipment between rows of solar panels can be complicated, Macknick said. Also, the income from solar is so much higher than the income from most crops that many farmers may not want to bother with crops on land with solar at all.

But there are exceptions, like organic produce sold at farmers markets and restaurants, which sell for higher prices than crops sold to food companies.

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Jack’s Solar Garden, near Boulder, Colorado, has become a leading example of a business that combines solar and agriculture, with partners that include NREL. Jack’s gardens include areas for growing wildflowers and other plants that help foster a habitat for bees, which is a common area of focus for several of the pioneering agrivoltaics businesses.

Macknick has learned from working with Jack’s and others that the crops that work best with solar can vary a lot depending on the local climate.

So, farmers may be able to grow big green heads of broccoli under solar panels in South Korea, but tomatoes may work better in Colorado; researchers and farmers are working together to figure out what works where.


Other stories about the energy transition to take note of this week:

Climeworks Building Giant Carbon-Sucking Plant in Iceland: Climeworks AG has begun construction on what may be the largest “direct-air capture” plant in the world, a facility that sucks carbon dioxide from the air and stores it underground. The plant in Iceland will be online in 18 to 24 months and have capacity to remove 36,000 metric tons of carbon per year, Kate Abnett reports for Reuters. The capacity is 10 times that of the company’s existing plant in Iceland, which is currently the world’s largest. Climeworks, based in Switzerland, is one of the leaders in a growing carbon-removal industry.

Offshore Wind Installations Surged Threefold Last Year: In 2021, countries connected 21.1 gigawatts of offshore wind energy to the grid, which was triple the amount in 2020, according to a new report from an industry group. The growth in offshore wind is happening as countries adopt clean energy policies to support development and as equipment costs decline, as Maria Gallucci reports for Canary Media. The growth in 2021 brought the cumulative total to 56 gigawatts, less than 1 percent of which is in U.S. waters. China was the leader in new construction last year, while the United States has many big projects in various phases of development, but has yet to complete any of them. 

The Netherlands Bets on a Nuclear Revival: The Netherlands plans to build at least two nuclear reactors in the near future, an approach to energy and climate change that is in contrast to its neighbors Germany and Belgium. Leaders in the Netherlands view nuclear as an important part of making a transition away from fossil fuels and while also meeting the needs of the population, as Alexander C. Kaufman reports for HuffPost, a story that also touches on the global debate over the safety and affordability of nuclear power.

Rooftop Solar Incentive Is Expiring in Indiana: Solar net metering is about to expire for Indiana consumers served by the state’s regulated utilities, which reduces the financial benefits of rooftop solar. The July 1 expiration means that rooftop solar owners will get a lower rate for the excess electricity that they sell back to the grid, as Sarah Bowman reports for The Indianapolis Star. The policy change is the result of a 2017 state law that began a phaseout of net metering in response to concerns from utility companies that the growth of rooftop solar would lead to a shift in costs of maintaining the grid to non-solar customers, since solar customers are paying much lower bills. The law affects customers who are newly installing solar panels, since people who already have solar will continue to receive the previous rates. Clean energy advocates say the new rules will not kill the solar market, but they will make rooftop solar less affordable for consumers.

Inside Clean Energy is ICN’s weekly bulletin of news and analysis about the energy transition. Send news tips and questions to dan.gearino@insideclimatenews.org.