[Dean Corren ’77]
By David McKay Wilson
On an unseasonably warm December morning in New York City, Dean Corren ’77 stood on the banks of the East River as a barge dropped anchor in the middle of the channel. A 15-foot turbine dangled from a crane on the ship’s deck, and as the apparatus was slowly lowered into the murky water, Corren’s normally impassive face betrayed just a hint of anxiety as the turbine slipped from view.
For the next six hours, divers worked in shifts to secure the turbine to steel pilings anchored 30 feet below the surface, and when all was in place, the machine’s three-rotor blades—powered by the river current—began to turn. On shore, Curren peered at a monitor, and allowed a smile to creep over his face.
Twenty-two years after he received a patent on a turbine rotor designed to tap the power of moon-driven tides, Dean Corren’s creation was generating electricity.
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“The energy is coming from the gravitational pull of the moon,” says the 51-year-old Corren. “It has the lowest impact of anything out there.”
Several months have passed since a pair of Corren’s turbines was installed in the East River as part of a pilot project run by Verdant Power LLC, and the Burlington, Vermont, resident is chatting to a writer about the zero-emission system that he believes could one day become an international model.
If Verdant’s 18-month pilot succeeds, as many as 200 turbines could be installed along the channel. It’s seen as a prime location—currents average four knots or higher; transmission lines are readily accessible; and, this being New York City, there’s a high demand for electricity. To put things in perspective, after just 40 days, the two turbines had generated more than 10-megawatt hours of energy, providing a substantial amount of power to a supermarket on Roosevelt Island.
Alternative energy enthusiasts favor kinetic hydropower because tidal currents are predictable, making it possible to sell a reliable stream of electricity to New York’s energy market. Environmentalists, though, have cautioned that the slow-moving turbine blades, which are 5 meters in diameter, could disrupt marine life. Federal and state authorities have required ultrasonic sensors to monitor the channel’s fish population.
Corren, who majored in philosophy at Middlebury, came to New York in the late 1970s to earn a master’s degree in energy science at NYU. His thesis developed a plan to combat the buildup of carbon dioxide in the atmosphere, then called “the greenhouse effect,” and recognized as the cause of what we today call global warming.
The late 1970s were a heady time for alternative energy research, with federal officials responding to the OPEC oil embargo by supporting research into renewal energy. Corren landed a job in an NYU research lab, where he designed the rotor that drives the electricity-generating turbines.
By the time his turbines were ready for testing in 1985, however, federal funds had dried up. An attempt to test them in Pakistan went awry after the computers shipped to record the data were stolen. So Corren put the project aside and moved on to other pursuits, which included becoming a founding member of Vermont’s Progressive Party, and winning election to the Vermont Legislature for four terms (from 1993 to 2000). Still, he never gave up hope that one day his rotor would turn turbines that produced emission-less electricity. He kept a stack of old floppy disks with this data, and displayed two small rotor blades on a shelf as a reminder. “It was never totally out of my mind,” he says. “We had tried—tried hard—to make it happen. There was just no money to fund it.”
While the project was shelved, his research remained alive in scientific circles through his published papers. In 1994, researchers at the Idaho National Laboratory, who were preparing a report on kinetic hydropower, found Corren’s studies and identified his design as one of the most promising.
Seven years later, Verdant CEO Ron Smith discovered the report while scouring literature for his startup firm, which was established to make kinetic hydropower a profitable commercial venture. He wanted to build on Corren’s research and came to Vermont to woo him.
By then, Corren had ended his tenure in the state Legislature, was helping run Bernie Sanders’ 2000 Congressional campaign, and had committed to heading up Sanders’ Vermont constituent services operation for two years.
He fulfilled that commitment as Verdant took Corren’s project from the scientific scrap-heap and began the arduous process of obtaining funding and regulatory approvals.
By 2002, the process was moving, and Corren left Sanders to become Verdant’s director of technology development. Today, he’s designing a new generation rotor, made of an alloy of aluminum and magnesium. It’s a more durable upgrade from the ones made of a steel skeleton and fiberglass skin.
With oil hitting $60 a barrel, and concern rising about the melting ice cap, both public and private funds are again flowing to alternative energy projects. Private venture capital and about $1 million from the New York State Energy Research and Development Authority back the East River project.
Even with the funding, getting the turbines into the East River was no easy task. It took three years to win approvals from more than 20 agencies, including the Federal Energy Regulatory Commission, which oversees hydropower generation.
By April, the pilot project was so successful that Verdant pulled out the original turbines and put in six new ones. The installation came a few weeks after FERC held a public hearing on Verdant’s plan to install 100 turbines there in late 2008. The proposal was met with strong public support that night. It was another sign to Corren that perhaps the tide had come in for kinetic hydropower.
David McKay Wilson is a freelance writer in New York.