The Future of Solar: Can Crops and Solar Panels Coexist?

Jan 30, 2025

By Michelle Lotker

By splitting sunlight, NC State researchers hope crops and solar panels can thrive together

Generating electricity from the sun is efficient and renewable. Solar installations, however, can take up a lot of land, and often the best sites overlap with prime farmland.

“Typically, they have a comfortable slope and level,” Ricardo Hernandez, associate professor at NC State, shares. “They typically are very clear, and they’re always full exposure to the sun.”

Ricardo and fellow researchers of the NCSU-CEA (NC State University–Controlled Environment Agriculture) Coalition (of which Ricardo is director) are concerned about keeping that farmland in agricultural production.

“That farmland is needed to produce food, and if we remove the capability of producing food in these farmlands, we have removed our ability to feed the population in the world. So, there is a conflict,” Ricardo explains.

That conflict could be resolved by combining solar energy generation with farming through something called agrivoltaics. Ricardo is working with collaborators at NC State and in Israel to develop new variations in solar panel design that will allow solar energy and crop production to happen on the same land.

“The idea behind it is, ‘Can we use the land for dual purposes? Can we grow crops in the field, in soil, and can we harvest the solar energy to generate electricity?’” Ricardo asks. “Great idea, but there [are] some challenges around it.”

Competing for sunlight

Solar panels and crops in the same field compete for sunlight because solar panels harvest the same light that plants need to grow. The challenge is how to design a way for plants and panels to share the sunlight.

Ricardo is part of a multinational team working to solve this by splitting sunlight between solar panels and the crops around them.

Sunlight can be broken down into different types of radiation based on wavelength, ranging from 320 nanometers all the way up to 3,000 nanometers. And a small portion of those wavelengths (ranging around 380–750 nanometers) is what we call visible light.

“Our eyes can detect that light. A similar range is also [used by] the plants to do photosynthesis,” Ricardo explains. “If you deploy these panels, you’re going to be removing those essential wavelengths, and the plant will actually have a big penalty in yield. We don’t want to penalize the production of food or the production of plant growth, because we already don’t have enough farmland in the world to grow crops. We want to prioritize plant growth. So in order to do that, we’re trying to actually split the sun.”

Splitting the sun

A key component to splitting the sun is a rather ordinary looking, very thick piece of glass that’s actually two sheets of glass glued together.

“This piece of glass has optics in the middle,” Ricardo explains. “It’s a film, and this film is what causes the reflection of absorption of specific wavelengths.”

Glass like this is often used in office buildings, where architects want to reduce the sun’s heat coming into the building without reducing natural light. They use glass designed to let visible light through while reflecting radiation with a longer wavelength, like infrared light.

Ricardo and his team are hoping to use similar glass to let plants get the spectrum of light that they need to grow while harvesting the rest of the sunlight’s radiation for solar energy production.

In a greenhouse on NC State’s campus, Ricardo propped up the sheet of glass with the wavelength-blocking layer and used sensors above and below the glass to show what light it reflects.

The glass blocked about half the total light or solar radiation in the greenhouse and a slightly lower percentage of photosynthetically active radiation, which is what plants use for photosynthesis.

“We want to maximize the amount of light that reaches the plant,” Ricardo explained. “We want to reduce the amount of light that is reflected or absorbed by the optics. There are still some inefficiencies, so that’s an improvement that we can [achieve] through research.”

A spectrum radiometer measures what parts of the spectrum are present and what parts are reflected by the glass. After taking a reading above the glass, Ricardo put the sensor below the glass to take another reading. Instantly, the shape of the rainbow-colored bell curve on the radiometer changed. The peak became sharper because less high and low wavelength light was present below the glass.

“You can see how we actually remove some of those wavelengths that are closer to the infrared,” Ricardo says.

This sensor shows us that the wavelengths of light reflected by the glass are mostly useless to plants, especially the wavelengths that just make them “hotter and thirstier.” But those wavelengths could be harvested for solar energy production.

New panel designs

To use this glass with solar panels, some changes have to be made to the traditional photovoltaic panel setup. In the model they’re testing, Ricardo’s team is orienting a double-sided photovoltaic panel vertically and angling the glass 45 degrees on both sides to bounce sunlight back at the panel while letting light through to crops underneath.

To test how much impact new solar panel designs might have on crops, the team uses mathematical models with information about how lettuce or tomato plants react to things like less light to predict the crops’ yield in different scenarios.

Shade-loving crops like lettuce only need a few more days in the field to have the same yield. But for sun-loving crops like tomatoes, the penalty is much higher, up to a 25%–30% reduction in yield. So there’s still room for improvement.

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Video: Can Gene Editing Give Seeds a Stronger Start?

Reagan Reed has a way of describing his research that might make a plant breeder pause.

“I’m the sort of person who likes to break things to understand them,” he says.

What he breaks are genes involved in seed germination. Reed, a Ph.D. candidate at the University of California, Davis, is investigating whether changing those genes can help seeds establish healthy plants under a wider range of conditions.

Reed recently attended the National Association for Plant Breeding meeting in College Station, Texas, as an NAPB Borlaug Scholar. His work speaks to a question that matters well beyond a research lab: what does it take for a seed to get a crop off to a strong start?

A seed that germinates quickly, alongside the others planted with it, spends less time vulnerable to stresses before seedlings become established.

“If you’re able to bridge that gap between germination to stand establishment, then that’s going to give you the highest probability of having a solid yield that year,” Reed says. “There’s a bunch that can go wrong after that, but it maximises your yield from the start, at least.”

Reed works in Dr. Imtiyaz Khanday’s lab at UC Davis, where his research focuses on seed quality in tomatoes and potatoes. He brings an unusual academic background to the work: at Skidmore College, he studied both biology and Latin.

Reed believes that combination prepared him for research. Translating an ancient text means studying each word, weighing its possible meanings and using context to reach the best interpretation. There is rarely a way to know with complete certainty what an author intended. Science, he says, requires a similar willingness to work through uncertainty.

“Attention to detail and comfortability working with uncertainty,” is how he sums up what Latin taught him.

In the lab, uncertainty can produce a surprise. Reed describes changing one gene and seeing little effect. Changing a second gene also appears to do little. Put both changes in the same genetic background, though, and the result can be substantial.

“I break this gene, nothing really happens. I break this other gene, nothing really happens. I combine them into the same genetic background, and now there’s a massive effect,” he says.

Those interactions matter as researchers gain the ability to edit multiple genes at once. They also complicate any simple account of how a trait works: improving a seed may depend on understanding what several genes do together.

For Reed, the question is whether that knowledge could help seeds germinate reliably when conditions are difficult. Some of the genes he studies prevent germination under certain conditions. That response may serve a plant well in one setting while limiting its usefulness in agriculture. He wants to learn what happens when those genes are changed, and whether the result improves establishment.

Yet a discovery that works in a lab still has a long way to travel before it reaches a field. Reed argues that agricultural biotechnology faces an economic challenge as well as a scientific one. New tools can create value for farmers, he says, but developing them requires a way to support the work in an industry where margins can be thin.

His fellowship with Flagship Pioneering gave him a view across AI, agriculture-related work and human health research. It also reinforced the importance of bringing people with different expertise into the same conversation—a benefit of gatherings such as the NAPB meeting.

“You need to have a team of people with different backgrounds who are willing to work together and approach the same problem in different perspectives and different ways,” he says.

That thinking connects the different parts of Reed’s path. Latin taught him to examine details without expecting a perfect answer. Gene editing lets him test what individual genes do—and what happens when their effects combine. Working with people beyond his own field helps him ask what those findings could become.

He came to agriculture because of its reach: the possibility that work by a small group of researchers could eventually make a difference on a much larger scale. His immediate focus is smaller and more precise. He wants to understand what helps a seed get through its first days and become a healthy plant.