Solar panels in a field at Knowlton Farm, Grafton, Mass. (Robin Lubbock/WBUR)

Paul Knowlton owns 300 acres of land in Grafton, and farms about 50. The farm has been in his family for five generation, ever since Knowlton’s great-great-grandfather settled in the Blackstone Valley in 1872.

These days Knowlton grows pumpkins, squash and corn. Up a gravel road, past the family cemetery, corn stalks are still standing from this year’s crop. “Considering the drought situation, we did fair,” Knowlton says.

Fickle weather and fluctuating prices make farming a risky business, so five years ago, Knowlton installed a new cash crop: solar energy. He turned 19 acres into two solar energy fields. “Doing the solar was very beneficial,” he says. “In the wintertime there is no revenue for a farm. It’s a tough game.”

Today, Knowlton’s 18,000 solar panels provide a steady income and enough renewable electricity to power nearly 1,200 homes. “Producing clean energy — there was no downside in my mind,” he says. “It was a go.”

Solar energy produces about 14% of Massachusetts’ electricity. That’s enough to power about half a million homes, and solar is growing rapidly — helping the commonwealth meet its clean energy goals.

But when it comes to energy generation, there’s no free lunch. Thousands of acres of Massachusetts forest and farmland have been turned into ground-mounted solar arrays. According to a recent Mass Audubon study, as much as a quarter of the land developed in recent years — like Knowlton’s field — has been converted to solar farms.

Read the rest of this story at WBUR’s website.