Solar-Powered Farming

There is a dark side to commercial solar farms, one that Michael Bendok, ’25, says is rarely discussed openly in the industry. Because crops and solar panels thrive in similar conditions—wide, sunny fields—much of America’s best farmland is being turned over to utility-scale photovoltaic operations.

It’s a move that can permanently alter the land that feeds us, as well as destroy valuable ecosystems.

“That’s why we want to come in and be a voice for nature, if you will, to solar developers,” says Bendok, CEO of Fundusol, a startup that hopes to facilitate the dual use of land.

He is part of a team of co-founders, all juniors, three from Stanford and one from Carnegie Mellon University in Pittsburgh, who in 2021 became spellbound with the idea of agrivoltaics, the thoughtful integration of solar energy production within farming.

“Agrivoltaics has the potential to change how we use our land,” says Peter Westbrook, ’25, co-chief officer of research and development at Fundusol.

The American Farmland Trust estimates that without policy intervention, 83 percent of new solar energy development is likely to take place on farmland, with half of that being on the nation’s prime land for producing food and other crops.

“Land is something that, as our society develops, we won’t get any more of—in fact, we could get a little bit less of it as the oceans rise,” Westbrook says. “So the ability to innovate on our land use is going to be really important to us as a society moving forward.”

Sunshine and shadows

It is perhaps no coincidence that three of the Fundusol co-founders grew up in sunny Arizona, where in Phoenix the thermometer surpassed 110 degrees Fahrenheit every day last July.

“It’s really hot, especially in the summer, and our summers are just going to get hotter and hotter,” says Esteban Herrera-Vendrell, ’25, co-chief research and development officer.

This home-state connection is what initially linked two of the co-founders during those early days of freshmen year when anything felt possible. One late night in September, Bendok rode his bike over to Herrera-Vendrell’s dorm to hang out at Stanford for the first time after connecting during orientation.

Somehow they started talking about high school research. Bendok mentioned his stint as a solar power intern, and what he learned about agrivoltaics. Herrera-Vendrell shared about a physics project where he modeled the temperature of an asteroid at any given point in its orbit.

“To do that, I had to consider the shadowing that the different parts of the asteroid surface produce on other parts of the surface, the incoming lights, and the actual thermal physics of the asteroid itself,” he explains—and that’s when it all clicked.

“Although it sounds like a completely separate problem, in agrivoltaics, it’s very important to consider how the placement of these photovoltaic systems affects their temperature,” he says.

Shadows can reduce the efficiency of PV panels, but so can too much heat. Solar panels lose productivity on the truly scorching days, with residential systems beginning to fail at 104 degrees and utility-scale systems at 122 degrees.

Agricultural crops also have a preferred range of temperature and sun exposure, which, in the right setting, can pair in a virtuous cycle with the microclimate created by solar panels.

“Could you write an algorithm for that shadowing?” Bendok wondered out loud.

Their conversation went on for four hours, well past midnight. And the next morning, it seemed less like a crazy idea and more like an actionable one.

Bendok, who came to Stanford with entrepreneurial ambitions, started putting the project in motion. They invited Peter Westbrook, from Kansas, to join them and shore up the computational and business side of the team. What about a computer scientist? Bendok said he knew someone too, and called Luca Borletti at Carnegie Mellon, a friend he’s known since seventh grade.

Even Herrera-Vendrell, who had never considered a startup before that fateful conversation, jumped in.

“It was just too good of an idea to say no to,” he says.

How it works

Over the past two years, the Fundusol team has built a platform to help farmers and ranchers optimize across multiple systems: electricity, irrigation, and the crops or livestock that they are in the business of raising. It’s not a one-size-fits-all approach.  

“It allows you to simultaneously optimize a design over these axes and get the best of both worlds according to whatever the farm’s needs are,” says Westbrook.

Luca Borletti, chief technology officer, says he was immediately drawn to the complexity of the problem.

“Agrivoltaics is the co-location of these really complicated systems, those being photovoltaics and crops—and biology is about as complicated as you can imagine,” he says.

In utility-scale operations, PV panels are usually installed low to the ground and in dense formations, maximizing the amount of land for converting the sun’s energy into electricity for the grid.

Agriculture is harder within this design—but not impossible. Farmers can underplant solar panels with wildflowers for honey bees and other pollinators, or allow smaller livestock like sheep or goats to graze on pastures beneath and around them.

Yet researchers are beginning to pilot other solar panel configurations that allow for the mutual flourishing of crops or cattle alongside renewable energy. Panels can be spaced at wider intervals and taller heights to permit livestock to pass underneath or to let rows of leafy vegetables catch more rays of the morning sunshine.

Agrivoltaic technology is a harder sell in northerly climates like New England, the Pacific Northwest, or the United Kingdom. But in the arid desert of the Southwest or in California’s Central Valley, solar panels can serve as an afternoon parasol of sorts to protect crops from the scorching sun.

Researchers from the University of Arizona found that the production of heat-sensitive cherry tomatoes doubled under PV panels, and the production of chiltepin peppers, a native spicy pepper that in the wild grows underneath trees, could triple under solar panels.

Ranchers can also benefit from agrivoltaics, as shade from solar panels can keep animals cool and less stressed. In both scenarios, the PV panels create growing conditions that are more temperate and, importantly, generate electricity to help power the farm or offset expenses.

Agrivoltaic installations on U.S. farmland are producing more than 7,000 megawatts of electricity on roughly 47,000 acres, according to the National Renewable Energy Laboratory (NREL) InSPIRE project—but this is only a fraction of what could be. One study identified over 860,000 acres that could benefit from agrivoltaics.

Energy extracurriculars

The Fundusol team says that managing a startup alongside their classwork is challenging, but that external support has validated their path.

In early 2024, the team won $10,000 from the U.S. Department of Energy through the Power Up Contest, a prize to support new and diverse entrants to the solar energy field. In 2023, Fundusol was awarded an Innovation Transfer Grant from the TomKat Center for Sustainable Energy. 

“Without the TomKat funding, my personal view is that we would not have the motivation to continue pushing forward,” Bendok says, pointing to how, especially as undergrads, there’s an opportunity cost to forgoing summer internships with other firms.

Fundusol will use the grant awards to attend the Agrivoltaics World Conference 2024 in Denver this summer, as well as the Solar Farm Summit in Chicago. With a growing client base, they hope to expand their team this year.

“My vision is that in the short-term, we can create a service that solves the hardest problems in energy with respect to solar,” says Bendok.

Fundusol is currently recruiting for summer 2024 internship and fellowship positions.  Stanford undergraduate students should apply for the opportunity to join them in expanding deployment of agrivoltaics.

This article is part of the TomKat Center Spotlight series designed to highlight the impact and trajectory of the work of faculty and students who received funding through our Innovation Transfer Program, TomKat Solutions, and Graduate Fellowships. Stanford University does not endorse any non-Stanford entities, programs, products, or services listed in the article.