UMass prof: farmland, solar arrays can co-exist

Monday, July 21, 2014
SOUTH DEERFIELD — What if you could use open space to generate solar electricity and farm it at the same time?

Stephen Herbert, a professor of agronomy at the University of Massachusetts Amherst, says this is more than a pipedream.

A demonstration plot at a research station in South Deerfield is doing just that.

“We have shown that we can get 90 percent of the yield of a pasture with solar panels compared with not having them as long as we leave enough space between clusters of panels,” he said.

Cattle and sheep graze beneath them. The animals also benefit from the shady spots the panels create.

The initial installation was 70 panels, which generate 26 kilowatts of electricity on less than a quarter acre. They are seven feet off the ground and are mounted on individual posts. The wiring connecting them is above ground.

Herbert said the demonstration plot experiments with spacing and configuration to find the sweet spot that allows maximum sun to reach the ground so the vegetation gets what it needs while the rest is captured for generating electricity. He also experiments with ways of driving poles into the ground to support the panels while minimally disturbing the soil.

“It’s a simple thing, but nobody is doing it,” according to Herbert, who said the demonstration plot, which has been up for almost four years, is the only one of its kind in the country.

Herbert believes that ideas like this one will get more attention in the years ahead as dilemmas around the balance between using land to grow food while generating significant amounts of alternative energy become more acute.

“My position is that we should make solar panels compatible with agriculture,” said Herbert. He thinks that in the future we will see dual use solar installations that can also be used for growing vegetables.

According to a description of this work on Herbert’s website, “only solar has the potential to substantially power the state while only using a reasonable amount of the state’s landmass.”

Herbert said he understands the benefits to farmers of leasing out land for a couple of decades to host solar arrays on fields they might otherwise sell to developers.

But he doesn’t think growing crops and generating electricity should be mutually exclusive.

“We don’t have 20 years to waste,” he said.