The Wind Regime 

AMC Outdoors, September 2007

Its energy drives boats and spins turbines, shapes trees and blasts them to bits. From the shores of Boston Harbor to the top of Mount Washington, come ride the atmosphere on a journey of escalating power.

I can see it from here. There in the distance, rising above Boston Harbor, the blades of a wind turbine steadily twirl. The atmosphere is moving today, flowing with energy, as we sail from Winthrop and set course for Hull. The canvas billows overhead as we glide across the bay, a sliver of fabric by the wind.

Though we do not directly sense it, air has mass. At sea level, 14.7 pounds of atmosphere—the equivalent of a column of water 34 feet tall—are bearing down on every square inch of your head. If all the air were sucked out of your body, it would instantly implode. Not because of the inward sucking pressure of an internal vacuum, but because the weight of the surrounding atmosphere would crush you. Fortunately air surrounds us, fills us up, and essentially supports itself, allowing us to exist without fear of an atmospheric crunch.

But when air starts moving, all that weight begins to exert significant force on obstacles in its path. And the faster it moves, the more powerful it becomes. As wind speed rises, the force it generates increases exponentially. A 40 mile-per-hour blow is four times as powerful as a 20 mph wind and 16 times as powerful as a 10 mph breeze—which is more than sufficient to power our 22-foot sail-boat across Boston Harbor today. This is the first leg of my journey through the wind spectrum, an exploration of rising atmospheric power and its effects on the Northeastern landscape.

We glide by Georges Island and past views of Boston Light, cruising toward the Hull Gut, a narrow passage between Peddocks Island and the tip of the Hull Peninsula. Surfcasters sit on the cobblestone shore, stalking striped bass. A short distance away, adjacent to the squat brick buildings of Hull High School, perched on the farthest promontory of land, sits the gleaming white wind turbine.

The blades of the turbine cut through the air above my head. I’ve returned to the site early one Monday morning to meet with Andrew Stern, one of the principal movers behind Hull’s wind efforts. A volunteer with the non-profit Hull Wind, Stern arrives off the ferry from Boston, clad in knee-length shorts, flip-flops, and a bright blue Hawaiian-style shirt. His enthusiasm for alternative energy—“I once built a solar-powered car and raced it from Orlando, Florida, to Detroit, Michigan”—is immediately apparent.

We stand at the base of the 164-foot tower, which rises from an octagonal concrete pedestal surrounded by flowering purple clover. “This is what clean energy looks like,” Stern says, craning his neck upward. The noise from the whooshing machine barely registers and we talk at a normal level; the sound of ankle-high wavelets lapping on the adjacent beach is more audible than the spinning blades overhead.

A small oval door is sealed off at the tower’s base, providing access to the six wrist-thick cables that deliver electricity to a small adjacent transformer box. Stern points across the sandy high school football field toward a utility pole, the start of a string of power lines headed south. “Over there. That’s where it pipes electrons straight into the grid. Not to be soapboxy, but you can read all the windmill stories you want. This is real.”

The blades on the 660-kilowatt turbine are 47 meters in diameter. This particular model—a Vesta V47—is a fixed rpm machine. No matter how hard the wind blows, it always spins at the same speed; the individual blades rotate and feather to compensate for increased velocities. At 6 to 7 mph, wind begins to generate enough force to spin the propeller, Stern explains, though this produces minimal electricity. When the wind reaches 12 mph, the turbine produces at 40 percent capacity. Output increases until the wind reaches an optimal speed of 20 to 22 mph. Little to no additional energy is produced at higher speeds. At a certain point, around 45 mph, the wind becomes too potent and the turbine automatically shuts down.

Installed in 2001 at a cost of $753,000, the turbine, known as Hull 1, generates approximately 1,600 megawatt-hours annually, enough to power about 150 households. Farther down the peninsula sits Hull 2, the town’s second wind turbine. With a blade diameter of 70 meters, it is “a newer, bigger model, with three times the capacity without being three times as large,” Stern enthuses. Together, the two turbines provide 11 percent of the town’s electricity needs.

But overall, Stern is unimpressed. “Two machines up in 10 years? I don’t think it’s a success. We gotta put more of these things up.” To that end, the town is developing a plan to install four 3.6-mega-watt wind turbines just off its northern shore. Once operational, the combined turbines would produce enough juice to power the entire 11,000-person community.

Such projects will shape the skyline in years to come, a highly visible manifestation of wind’s influence on the Boston landscape. But Hull is fortunate, its seaside location providing the consistent breezes needed to make these efforts viable. Farther inland, dense forest and a rumpled topography slow down air flow into an irregular and temperamental force. Here wind’s power is not evidenced by man-made structures; it’s in the trees overhead.