In 2022, moving solar panels shielded French apple trees from extreme sun, cutting sunburned fruit from 13% to 2%

In 2022, sunburn threatened 13% of the apple harvest in a French field trial. That same season, researchers tested whether panels installed above a separate set of trees, shading them during the sun's most intense hours, could reduce that damage. A field study shared in the AgriVoltaics Conference Proceedings showed that the shaded trees had just 2% sunburned fruit, compared to 13% on the unshaded control trees grown right alongside them.

Why apple sunburn is a bigger deal than it sounds

This skin damage lowers the apple's visual quality and market grade, which can reduce its value in the fresh produce market. The fruit may no longer be suitable for fresh-market sale. As a result, growers often sell the fruit cheaply, usually for juice. That matters because apples take a full season to grow. Early-season and prolonged heat waves are becoming more problematic for growers in apple-growing regions.


How the French researchers tackled the problem

Shading the trees is straightforward in principle. Doing so without harming the tree is another matter. Scientists at Sun'Agri used an agrivoltaic system in the study. The system placed solar panels above the tree canopy. These panels adjust their positions throughout the day. The panels rotate to block the strongest sun and then turn away to let light through.

What the two-year data showed

Scientists compared shaded trees with unshaded control trees over two growing seasons. According to the AgriVoltaics Conference Proceedings study, sunburn damage in 2022 measured 13 percent on control apples compared to 2 percent on apples grown under the shading panels. The difference was unlikely to be due to chance alone. In 2023, sunburn damage was minimal in both samples. The shaded fruit was also cooler, with maximum surface temperature up to 3.3 degrees Celsius lower than the unshaded fruit. One other finding stood out. The apples' size remained the same for both samples. Shading the trees did not reduce crop size, avoiding one problem while addressing another.

Why federal researchers are paying attention

This is not limited to one French orchard. The U.S. Department of Agriculture's Climate Hubs has found that agrivoltaic systems, which are panels that are raised six feet above crops like apples, berries, and grapes, can be very helpful. These agrivoltaic systems can reduce how much sun crops are exposed to and protect them from severe weather. The agency says that we still need to do research to see if this works everywhere, but so far it looks like these systems could be very good for food and energy security. Funding reflects that interest: the USDA's Economic Research Service reports that the agency provided $10 million for agrivoltaics research in 2021 through its National Institute of Food and Agriculture, plus another $2.2 million in 2022 through the Partnerships for Climate-Smart Commodities program, bringing the total to roughly $12.2 million as of that 2022 report; additional funding may have followed in the years since. Together, these programs aim to learn more about agrivoltaic systems and how they can support food and energy security.

The same idea is now being tested on US soil

The federal government is also paying close attention to orchard-based agrivoltaics. According to WSU Insider, Washington State University's Institute for Northwest Energy Futures received a $2.4 million grant from the Washington State Department of Commerce to fund the project. The grant will help build an orchard at the Sunrise Research Orchard near Wenatchee. The orchard will combine solar panels and apple trees on the same site. WSU is working with a company called Sun'Agri on this project. The team wants to see whether panels over trees can prevent sunburn, as in the French test. The trial will test whether the approach works in the Pacific Northwest.

Cornell University is running a similar project in New York. The project plans to install a 300-kilowatt solar array over about 1,100 apple trees, but researchers are first testing shading methods using cloth, at different heights, to work out the right approach before the solar panels themselves go up. They want to see whether the system can protect trees from heat and hail. They are using cloth to shade the trees and testing how it performs at different heights.

Why this should matter beyond the orchard

For shoppers in US supermarkets, this study may be more relevant than it first appears. Climate change threatens affordable apple supplies, and sunburn can push good fruit out of the fresh-market supply chain into cheaper juice sales, raising prices for the apples that do make it to store shelves. Agrivoltaics can help orchards preserve crop quality while generating additional revenue from electricity.

This technique is not a universal solution for orchards worldwide. Installing solar panels requires significant investment, and results vary by region and apple variety. In addition, most pilot projects in the US, including those in Washington State and New York, are still underway and have not yet reported results. The French study provides concrete figures rather than promises. The key question is whether US orchards can reproduce these results under local conditions.