Environmentalists usually love solar panels. But are they quite as lovable if you cut down a tree to put one up?
That's what's been happening in Massachusetts. The state Department of Energy Resources estimates that approximately 2,500 acres of trees — equal to the size of 50 Boston Commons — have been cut down to put up solar panels in the last 10 to 15 years.
The trend is particularly pronounced in the western part of the state, where some residents and environmentalists are worried the demand for cleaner energy is destroying some of their beloved forests.
Earlier this week, Barbara Stringer and her neighbor Bill Mara walked through the woods behind their Pittsfield homes. Tall trees all around them were just starting to bud. These woods have been proposed as a site for a new solar energy farm.
As they walked, Mara pointed to a spot in the woods. "That yellow stake over there," he said. "That's where the panels will start."
The plan would clear about half of the 57 acres.
"Imagine cutting down all these trees," Stringer said. On top of the fact that the proposed project is right behind their houses, Stringer says it would destroy wildlife habitat here. "I'm all in favor all of alternative measures of energy," she said. "But there's a right and wrong place for it. And I just feel this is not the appropriate spot."
The company that has proposed the project, Cypress Creek Renewables, said it's trying to address the neighbors' concerns — setting the project further back from their properties and taking steps to preserve the ecosystem with fencing that would allow wildlife to pass through and vegetation that pollinators like.
And, the company says, the solar project would provide clean power to about 700 homes. It's that demand for clean power that's leading to an environmental dilemma.
Michael Judge, who directs the Renewable and Alternative Energy Division at the state Department of Energy Resources, says Massachusetts has aggressive goals for reducing carbon and other greenhouse gases, and solar is a big part of the state's plan.
"We are very heavily forested in Massachusetts," he said. "I think it's something like 60 to 70 percent of our land is covered by forests. So when you start trying to site projects for solar, you're going to find that a lot of those products are going to end up in forested or partially forested areas."
"The idea that cutting down trees to put up solar panels is a net positive is just ridiculous," said Jane Winn, the executive director of the Berkshire Environmental Action Team. "Once every rooftop and parking lot is covered with solar, then we could see considering where else we might want to put [panels]."
On a breezy, sunny afternoon this week, Palmer Moore, a vice president at the solar energy company Nexamp, walked around an array of about 8,000 solar panels in Monson. These panels are on an old farm, so he said they didn’t have to cut down trees. But they have for other projects, and Moore said sometimes that's because private landowners reach out to companies like his.
"I think the reality is, is if that person's out looking for something to do with their property, they're gonna do something with it," he said. And solar panels, he added, are a much better option for the environment than alternatives like residential developments.
But when it comes to fighting climate change, which is better: solar panels or trees?
John Reilly, co-director of MIT's program on the science and policy of global change, did the calculation. He looked at how much power you’d generate if you clear-cut one hectare — or about 2.5 acres — and put up solar panels. He figured out you’d make up for all the carbon stored in those trees in just 46 days, if you were preventing that same amount of energy from being generated by carbon-emitting coal, or 23 days, if you were offsetting natural gas.
"There is a carbon loss from the trees, but it's made up fairly quickly," he said. "You're going to operate that solar panel for 20 years."
But trees offer a lot more than just storing carbon, and Massachusetts is trying to discourage clear-cutting.
The state’s solar program pays solar companies less for power that’s generated by panels sitting on land that used to be forested. But environmental groups say the regulations don’t go far enough to protect forests.
That could change. This spring, the state Department of Energy Resources plans to review the solar program. And its director said they'll be looking at how to stop solar panels from threatening forests.
Correction: An earlier version of this article incorrectly stated the size of one hectare. One hectare is equal to 2.5 acres.