The world's leading source of technology news and analysis
Search Spectrum IEEEXplore Digital Library Submit
Font Size: A A A
IEEE
Home [Alt + 1] Magazine [Alt + 2] Bioengineering [Alt + 3] Computing [Alt + 4] Consumer [Alt + 5] Power/Energy [Alt + 6] Semiconductors [Alt + 7] Communications [Alt + 8] Transportation [Alt + 9]

Wind Power in Paradise Continued By Erico Guizzo

First Published March 2008
emailEmail PrintPrint CommentsComments ()  ReprintsReprints NewslettersNewsletters

Photo: MARTIN BERNETTI/AFP/GETTY IMAGES

sinking ship: In 2001, the Ecuadorian tanker Jessica ran aground near San Cristóbal, the Galápagos’s easternmost island, spilling more than half a million liters of fuel.

ON A SERENE afternoon last September, I head to the highlands of San Cristóbal with Jim Tolan, an American engineer who, along with Vintimilla, manages the project.

“The place we’re going, it’s called El Tropezón Hill. I think that means ‘big stumble,’ so watch out,” Tolan quips as we hop into a Chevrolet pickup. “Oh, and grab your rain jacket.”

We drive up a dirt road, and the coast’s arid, volcanic landscape metamorphoses into steep, grassy hills dotted with Miconia robinsoniana, a leafy shrub with purple flowers that you won’t find anywhere outside the Galápagos. A dense white mist suddenly engulfs our vehicle. The blue sky disappears, as do the road and the hills. It’s like riding through a cloud. Tolan explains that this is the garúa season: cold winds and ocean currents cool the air, and a heavy fog and drizzle—the garúa—forms in the highlands.

We park, and only after I get out of the truck do I realize we’re standing next to a steel tower as tall as a 15-story building, topped by a three-bladed rotor. Two identical towers perch nearby. Erected a month ago and now beginning operation, they are state-of-the-art wind-power turbines imported from Spain. Through the dense fog, I can barely make out the blades—each about the length of a jumbo 747 wing—but I can hear them turning with a thunderous, cadenced whoosh.

The presence of massive wind turbines in the Galápagos may sound incongruous, but as any visi­tor quickly realizes, the islands are no longer the deserted paradise that first captured Darwin’s imagi­nation more than 170 years ago. Today the archipelago, which consists of 13 main islands and numerous islets and rocks, is home to more than 20 000 people, most of whom work in tourism or subsist on fishing and farming. An additional 120 000 visit annually, and that number continues to swell each year.

One result of all this human activity is a higher demand for electricity. The diesel generators on the four inhabited islands burn some 13 600 L every day. The fuel for the generators, and also for cruise ships and auto­mobiles, arrives by oil tanker from mainland Ecuador. Over the past decade, the number of tankers coming to the islands has jumped from a few per year to a few per month now. For years, conservation experts dreaded an oil spill. On 16 January 2001, it happened.

That night, the Ecuadorian tanker Jessica took a wrong turn near San Cristóbal’s harbor, rammed into a reef, and ran aground, leaking more than 500 000 L of diesel and bunker fuel. The spill dirtied sea lions and tortoises and killed a handful of pelicans and seagulls. Only a sudden change in ocean currents, which washed the oil out to sea, prevented the spill from becoming an even bigger ecological disaster.

The incident served as a wake-up call. Not long after, the Ecuadorian government decided to invest in renewable energy for the archipelago, and it teamed up with the United Nations Development Programme and the e8—an international consortium of electricity companies that supports energy projects in the developing world—to launch the US $10.8 million San Cristóbal Wind Project.

The goal of the project is to build a 2.4-megawatt wind system that will supply 52 percent of San Cristóbal’s annual electricity needs, on average. It might not seem like much, but that means reducing the amount of diesel burned by 950 000 L and preventing 3000 metric tons of carbon dioxide from being dumped into the atmosphere every year. “More important, it should reduce the number of tankers coming to the island,” Vintimilla says, “and so, the risks of another spill.”

I’M INSIDE WIND TURBINE NO. 1, ascending a narrow ladder that stretches upward for 50 meters. Inside this giant white-walled tube, with the fluorescent lights flickering, I almost forget I’m in the Galápagos. It’s more like being in a spaceship.

Looking up, I see a pair of legs belonging to José Moscoso, the site’s operations manager; below me is Tolan. At the top of the ladder, we unhook our safety harnesses and squeeze through an opening to get inside the nacelle, the turbine’s uppermost structure, which houses the generator and holds the blades. Powerful motors can rotate the nacelle so that the blades always face the wind. Made of fiberglass and polyester resin, the 29.5-meter-long blades sweep an area of 2700 square meters in a single rotation, the equivalent of six basketball courts.

The three blades spin at relatively low speeds of up to 25 revolutions per minute. A ­gearbox ups that rotation to between 750 rpm and 1650 rpm, to drive the 800‑­kilowatt generator, the heart of the machine. “That’s what makes everything possible,” Tolan says, pointing to a massive piece of steel and iron the size of a Volkswagen Beetle. “The flow of air becomes the flow of electrons.”

The generator produces alternating current whose frequency depends on how fast the wind is blowing and turning the blades, he explains. The electricity then flows into a cable that runs down the tower. Near the bottom, a rectifier converts the ac to dc, which then goes into an inverter for conversion back to ac at the desired frequency of 60 hertz. Finally, a transformer boosts the voltage to 13.8 kilovolts.

Moscoso opens a small hatch in the ceiling of the nacelle and takes a peek outside. How’s the view? “Está toda nublada,” he says. “It’s all cloudy.” Tolan tells me that on a clear day you can see almost the entire island and the deep blue Pacific all around. “It’s a million-dollar view,” he says. “To the south, there’s nothing but ocean from here to Antarctica.”


Related Audio
« Previous Page 2 of 6 Next »
emailEmail PrintPrint CommentsComments ()  ReprintsReprints NewslettersNewsletters