Solar panels soon may power, protect apple orchards

A small experimental apple orchard at Cornell's Hudson Valley Research Laboratory may soon be topped by solar panels - which would not only track the sun to capture energy but provide a warm canopy on cooler spring days and shade the trees from excessive heat.

The research lab proposes to install a 300-kilowatt solar arrangement next spring to cover about 1,100 apple trees. The single-axis movable energy array 12 feet above the ground to take advantage of the land by producing food and power.

"Nobody in North America has ever covered an apple orchard with solar panels," said Jared Buono, director of the laboratory, located in Highland, New York. "This is all about farm viability."

Agrivoltaics - the idea of growing viable crops while concurrently harnessing the sun's energy with solar panels - is not a new concept. Buono and his colleagues aim to demonstrate how the panels can be used to protect growing apples from extreme weather, including hail, in a changing climate. To simulate solar panel conditions, for now, the researchers have installed agricultural mesh at three different heights to learn how the young, densely packed dwarf trees and fruit respond.

By next summer, with an installed array centered over the high-density orchard, Buono can examine how varieties and rootstock react to covered or uncovered conditions.

"We'll track the sun," he said. "When we want to let sunlight in, we'll be able to anti-track the panels. When we want to keep the sun off the trees - apples can get sunburned - we'll be able to cover them."

Through New York's Climate Leadership and Community Protection Act, signed into law in 2019, the state aims to reduce greenhouse gas emissions by 40% by 2030 and then 85% by 2050 from 1990 levels. Science and agriculture are looking for ways to help achieve those goals.

"This research could help New York meet climate goals while keeping farmers farming and keeping the food system vibrant," Buono said. "We have options. This research is providing possibilities for growers while we produce sustainable renewable energy."

Meanwhile, at a solar farm project in Ravena, New York, extension associate Caroline Marschnerhas planted a fall crop of lettuce, spinach, radishes and raspberries under a large commercial array of tilting, single-axis solar panels.

She received permission to plant in late August, but it took a few weeks to get the ground tilled and prepared.

This Cornell Agrivoltaics Research program - led by Marschner, Toni DiTommaso, professor in soil and crop sciences (CALS); and Steve Grodsky, assistant professor courtesy in natural resources and the environment (CALS) - is funded by New York state to assess how crops can flourish under existing panels.

"In a short period of time we've learned a great deal about issues that producers will face farming crops in an existing solar facility," Marschner said. "There are wires carrying electricity everywhere. There are insurance matters to understand. There are entrance and safety requirements when working around high-voltage electricity."

In western New York, Cornell students under the guidance of Max Zhang, the Irving Porter Church Professor of Engineering, in the Sibley School of Mechanical and Aerospace Engineering, found that agrivoltaics in Concord grape vineyards could create mutual benefits for growers and solar developers, while accelerating power grid decarbonization. Their research is expected to publish later this fall.

"We're studying all aspects of agrivoltaics so that farmers and policy makers can make informed decisions," DiTommaso said. "It's a different ecosystem from all perspectives, like pest management and weeds. We've got these solar panels, so rain will be concentrated and air movement changes. Agrivoltaics farming is so new, I have no other comparison to this system."

DiTommaso and Grodsky are faculty fellows, and Zhang is a senior faculty fellow at the Cornell Atkinson Center for Sustainability.