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.
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.
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.