Dual harvest: Power and produce straight from the farm

Massachusetts is known for its dedication to solar energy, as well as its efforts to increase the amount and availability of fresh local produce across the state. These two green goals, however, can sometimes end up as competing interests as energy companies eye large expanses of farmland for the installation solar arrays.

With farmers increasingly using land to harvest the sun where they once grew crops, the farm at the University of Massachusetts Crop and Animal Research and Education Center on North River Road in South Deerfield is offering proof that solar arrays and agriculture don’t have to be at odds, but can actually exist together within the same field.

It is called “dual use” and, according to Steven Herbert, professor of Agronomy with the Stockbridge School of Agriculture, who runs the research project at the farm, it is the only farm of its kind in the country.

“Our philosophy is that we can put solar panels out in a field to help support the economics of a farm, while still keeping productive land in agriculture,” Herbert said.

While some farms may grow certain crops near solar arrays, none actually grow food crops directly under the panels as they do at the South Deerfield farm, Herbert said.

At present, the dual use demonstration portion of the farm sports two long parallel rows solar panels roughly 9 feet in the air. Each row has 36 panels for a total of 72.

A variety of crops grow directly underneath the panels and the garden has successfully produced things like kale Swiss chard, lettuce, beans, broccoli and peppers for the past two years.

The project began to take shape in 2010.

Most large-scale solar installations are close to the ground, and site preparation can involve removing vegetation, re-grading and compacting soil. Here, the goal was different and simple: Build a solar array high enough to allow sunlight to reach the ground in order to facilitate growing crops and animal grazing.

“We had to start for scratch, because it hadn’t been done before,” Herbert said.

The installation began with 17-foot poles, eight inches in diameter, driven eight feet into the ground to save the space taken up by concrete footings.

The polls support a racking system for the solar panels, which are arranged on sliding bases in clusters of three.

This allows Herbert and his team to move the panel clusters in sections of two to five feet apart, test the amount of sunlight that gets through at different intervals, and how this effects the health and yield of various crops.

In the full-sun area in front of the solar array, the team has planted a control row of crops to compare with those grown under the panels.

“This is the second year that we have done this,” Herbert said, noting that during the first few years of the project the land was used to graze cattle.

“As long as we had a gap of three and a half to four feet between the panels, we had 90 to 95 percent of the yield that we had in full sun,” he said. “So if you are a cattle or dairy farmer, you could do this and have no reduction in yield.”

Information on the construction of the solar arrays, and crop data collected over the growing seasons can be used to assist farmers interested in investing in solar while maintaining the agricultural productivity of their land.

Herbert said that there are a few farmers in the area who are thinking about doing this on their land but to date, nobody has actually done it.

Gerald Palano, an engineer projects coordinator with the he Massachusetts Department of Agricultural Resources says he hopes a new agricultural grant program will encourage farmers to participate in dual use farming, and help inspire new and innovative solar applications for agriculture.

The Massachusetts Department of Agricultural Resources Agricultural Energy Grant Program funds agricultural energy projects in order to improve energy efficiency and the adoption of alternative energy by Massachusetts farms.

That department has partnered with the Massachusetts Department of Energy Resources, creating a new “special projects” grant issued for the first time in fiscal 2017.

The special projects program awards grants in six specific energy efficient and renewable energy categories, including “Dual Use of Land for Solar Photovoltaic” which has a maximum award of $100,000

“There are certainly a lot of farms that have taken land out of production for solar,” Palano said, adding that the financial benefit of doing so is sometimes the only thing that keeps a farm in operation.

“If a farm chooses to do that to keep their farm up and running, we respect that,” Palano said. “But we would also like to be able to give farmers the incentive to make dual use work.”

Massachusetts has a progressive solar energy program with a target of producing 1,600 megawatts of solar power by 2020.

The state also a has a Local Food Action Plan that was created in 2015 to increase the amount of food grown in the state, reduce hunger and food insecurity and make healthy food accessible to all residents.

Palano says that dual use is an excellent way to achieve both of these goals.

“The more we can do to use what we have, the more we can contribute to both agriculture and solar energy,” Palano said.

With more than half a million acres of farmland in Massachusetts, he says that the possible applications of dual use of agriculture and solar are exciting, as systems could be tailored to the needs of the farm and the crops that they grow.

“Farms are constantly rotating crops so we don’t want to come up with a system that works with just one crop,” he said.

Palano said that countries like Japan, France and Germany are already working on solar arrays designed for dual use situations,

“They are all making a go at it with similar styles, some 12 to 14 feet high and growing crops underneath,” he said.

Other innovations include single pole towers with 16 to 24 panels at the top of the pole.

As Massachusetts move forward with goals of agricultural land preservation and the production of solar energy, Herbert hopes that his research will help resolve what he calls the “ethical dilemma” of having to choose one over the other.

“We shouldn’t be putting solar up on productive agricultural land. Here we show that the two can coexist,” he said. “This is not the only way to do it, but it is a very simple way.”