Some use the water, sun, and wind for adventure. Others turn these forces into electricity. A small elite do both.
By David Ferris
Research Associate PRofessor, University of Maine
Photo by Trent Bell
The largest whirlpool in the western hemisphere lies in a channel on the coast of Maine and does curious things to the water. Ferocious tides race over deep outcroppings, causing the smooth surface to suddenly rip apart or to issue rude burps. The whirlpool is known as Old Sow, and its eddies are called piglets.
It was probably a piglet that grabbed Gayle Zydlewski's research vessel one afternoon in June 2010 and spun it silently on its keel. The anchor line wrapped itself around her bundle of underwater sensors. Then the aluminum arm that held them to the boat started bending and warping like tinfoil. "Cut the mooring line!" she yelled to the skipper. He hesitated. She added, "This gear is worth $100,000!" The skipper cut the line.
That day's rescue of a sonar camera and a single-beam fish finder allowed Zydlewski to continue a five-year exploration of what lies below the surface of Cobscook Bay. Her quest has far-reaching consequences for the capture of tidal energy. Last September, the Ocean Renewable Power Company became the first to deliver tidal power to the U.S. grid when it bolted a 98-foot-long turbine, shaped like a set of old-school lawnmower blades, to the estuary floor. Zydlewski's job is to find out what happens to the fish when you do that.
She is well suited to the task. In her spare time she has battled six-foot sailfish off the coast of Florida and teased golden cutthroat from a Yellowstone stream with a fly rod. For work, as a fish ecologist at the University of Maine, she eavesdrops on sturgeon as they migrate from the Penobscot River to the ocean.
Nothing defines Cobscook Bay like its tides. Rising and falling about 24 feet, a larger swing than anywhere else in the United States, it exchanges vast quantities of phytoplankton with the sea through its narrow mouth. Generations of Americans grew up on Cobscook Bay sardines. There were always jobs on the fishing boats or in the canneries, at least until the 1970s, when the fisheries crashed. Now, there is hope that a thriving industry of tidal turbines could replace the jobs that left with the fish. And of course, everyone would prefer that the underwater foils create carbon-free electricity without altering the bay's herring hatchery. Zydlewski wants her observations to determine how many turbines can be safely placed in the estuary. Even more important, she wants to establish techniques that scientists can use to evaluate the impact of turbines on other bodies of water.
During the first-ever fish survey of Cobscook Bay, Zydlewski's team took six-hour-long shifts wading in 47oF water with a seine to catch a few rainbow smelt. I joined them as they boarded a trawler that dragged the ocean bottom with a net. The dripping contents were dumped on the deck, where researchers sorted halibut from sculpin and pawed through piles of scallops, which clattered like poker chips.
The most important data come from those devices that Old Sow almost claimed. A graduate student spends all night on board a ship recording the acoustic blips from a fish finder. Reading piscine behavior in a swift tidal current, at depths of more than 80 feet, is like pointing through fog with a flashlight.
After three years of collecting data, Zydlewski can report that even in fast-flowing currents, fish tend to swim around the turbine during the day, and that those under 10 centimeters long are more likely to swim through the turbine's foils. "It's amazing the things we don't know still," she muses.
Mechanical Engineer, Makani Power
Photo by Mitch Tobias
Wing 7 crouches, a black, fearsome-looking thing 25 feet long with propellers lashed down and wires sprouting from its brain console. Technically speaking, it's a kite, but it looks like a wing that scurried from a stealth jet and grew two arms, four props, and a tail.
Makani Power's Johnny Heineken points out the motor pylons, the arms that hold the propellers in place. They were hard for him to prototype, he explains, because they had to be asymmetrically foiled to counteract the inertial forces of the motors. I struggle to square his technical lingo with his sun-bleached good looks. Heineken, 25, is tall and lean, with a mop of curly blond hair you might expect on someone who shares a name with a crisp Dutch lager.
"There's tons of intricacies to make this thing controllable," Heineken says, and right then the wing's ailerons twitch, as if we had startled it. "This is when we hope they don't have the high voltage on," he adds.
By day, Heineken machines the parts for an intelligent, autonomous, energy-generating carbon fiber kite that Makani believes can harvest wind power more cheaply than the giant horizon-altering wind turbines we use today. On evenings and weekends, Heineken is one of the world's fastest kiteboarders. He won the world championships for course racing in 2011 and again in 2012.
To turn wind into electricity, Makani starts with a Ford F-650 truck whose bed holds a tower of strange machinery. The kite hangs from the tower, and when wind conditions are right, the propellers buzz to life and the wing lifts off like a helicopter to an altitude of 400 meters, a tether unspooling behind it. There it catches the crosswind and flies in giant circles. The propellers cease using power and start generating it instead, sending electrons down the tether line to a bank of batteries. Using a fraction of the materials of a big steel wind tower, the wing can catch higher, stronger winds.
Wing 7 produces so much lift that it requires the entire 26,000-pound weight of the truck to stay anchored to the ground. Yet it is just a prototype of a commercial model that Makani hopes will produce 20 times as much power and have the wingspan of a Boeing 737. An even larger model is planned for installations at sea. Google likes the idea so much that in May the search engine giant acquired Makani.
Heineken takes me to Crissy Field in San Francisco, the center of the Bay Area's kiteboarding scene. It neighbors the St. Francis Yacht Club, where Heineken raced sailboats starting at age 12. In 2009, while getting his mechanical engineering degree at the University of California, Santa Barbara, Heineken tried kitesurfing and realized that by eliminating the boat, he could sail 10 knots faster. He loved, he says, "the logistical ease of doing something so fun and free-feeling."
Kiteboards come in many shapes and sizes, meant to catch big air or rip along in high winds, but the one Heineken has designed, with three long pectoral fins, is purposed for maximum speed in any wind. It is suited to course racing, which requires a kiteboarder to navigate a three- to five-mile course, much like the sailing races he grew up with.
Lines braced to his waist, Heineken sends his green kite aloft. He dances across the sand to grab his board as it hits the water, then rockets off toward a buoy and doubles back. At the moment when it seems that he will run aground, he prances around his board like a spider and zooms off again, until he is a dot racing toward the Golden Gate Bridge.
David Ferris is a frequent contributor to Sierra.
This article was funded by the Sierra Club's Climate Recovery Partnership.
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