In the past, building solar on farmland has generally meant taking fields out of production, replacing crops with solar panels. Dual-use developments, however, call for solar panels built at a significant height above the ground – Massachusetts policies call for a minimum elevation of 10 feet – and spaced farther apart than in conventional arrays. The added space under and around the panel is intended to allow in enough sun to grow crops for harvesting or for animals to graze.

Solar developers and other experts familiar with the Massachusetts program attributed the low adoption rate to a combination of factors. They include a lack of familiarity with the concept among farmers, as well as the state’s relatively strict definition for which projects qualify, which some say is too narrow and conservative. 

“They’re being very careful about how they’re qualifying projects,” Winter said.

The program’s rules also had to be tweaked several times to answer questions and smooth out issues that cropped up as the first projects rolled in. While that process was necessary, developers say, it also made it more difficult to reliably plan and budget projects. 

The state solar incentive program has allocated 80 megawatts of its capacity to agrivoltaic developments, providing a higher incentive rate to these projects. The rules require solar panels to shade no more than 50% of the growing area and have strict rules regarding elevation. These guidelines apply regardless of a field’s soil type, what plants will be grown, or whether the land will be used for crops or grazing. 

A better approach might be to focus less on prescribing the specifications of the array and more on outcomes, Winter said. Some places in Europe, for example, have a production threshold that requires dual-use farmland to achieve a certain percentage of its previous productivity.

The novelty of dual-use arrangements can make it tricky for farmers and developers to get a reliable handle on how a new system will work. It can be difficult to predict results in a system as complex as farming, said Dwayne Breger, director of the Clean Energy Extension at the University of Massachusetts Amherst. Variations in crops, soil type, and farming techniques can all change the outcome. And changes in weather patterns from year to year mean the results from one year offer only limited information. 

“There’s an issue with regard to the uncertainty,” Breger said. “It’s hard to come up with definitive information because there’s so many parameters.”

There is also a lack of widespread understanding about dual-use strategies among farmers, Marley said. Farmers operate on tight margins, so taking a leap into a new approach can be daunting without more familiarity with dual-use and its results. And so far there are only a few examples to look to in Massachusetts. 

“Once there are more results, I think there will be more acceptance,” Marley said. 

Despite these obstacles, it is widely agreed that progress is accelerating in the dual-use space.

Breger helps the state review predetermination applications for the dual-use incentive, a step that helps developers spot potential problems and work them out before a formal application is submitted. Over the last few years he has seen an uptick in the number of these predetermination requests coming through. In the last few years, he said, there have been roughly 30 projects that have completed this early review and there are another dozen in progress. 

The frequency of rule changes has also leveled out, leaving developers with a much better ability to plan projects, said Nick d’Arbeloff, vice president of commercial business for SunBug Solar.

“They polished the policy in a good professional fashion,” he said. “We can now build a system with good confidence that everyone understands how it works.”

The dual-use projects that are operational in the state show promise. In western Massachusetts, Nathaniel Tassinari worked with SunBug to build a 250-kilowatt array on the family farmland he owns in the town of Monson. The project, a community solar development dubbed A Million Little Sunbeams, came online in 2020. The system uses a single-axis design and panels that track the sun throughout the day. The array is elevated above fields where the farm grows hay as fodder for dairy cows. 

So far, the panels are outperforming the modeled expectations by some 15% and there has been no noticeable impact to the hay, Tassinari said. 

“We can’t really see a discernible difference between underneath and not underneath,” he said.

The project is already serving as inspiration for others interested in the concept. Tassinari estimates he gets about 100 “solar tourists” each year, many of whom are solar developers or farmers trying to get a better feel for how the idea works in real life. 

The concept is also gaining traction outside of Massachusetts. The largest dual-use development in the country, a 4.2-megawatt array erected above blueberry fields, debuted in Maine last year. New Jersey has launched a dual-use pilot program and conversations are heating up in states like Pennsylvania, New York, and Illinois, Ward said. 

In 2020, the U.S. Department of Energy awarded $7 million in grants to four projects across the country investigating aspects of combining solar panels and active agriculture. Breger’s team at the University of Massachusetts was awarded $1.8 million to conduct ongoing research at eight pilot sites, including the country’s first solar installation over a cranberry bog.

Current climate and economic conditions may also help push more farmers to consider agrivoltaics. As hotter, drier summers become more common, the shading provided by the panels might actually be beneficial to some crops, Breger said. At the same time, rising fossil fuel and electricity prices could make solar energy even more attractive than it is already, D’Arbeloff noted. 

And agrivoltaics advocates are determined to push through the remaining obstacles, Ward said. 

“We’re not letting it fail,” he said. “We’re pushing the envelope on acceptance of this.”

This article first appeared on Energy News Network and is republished here under a Creative Commons license.