There’s good news, and there’s bad news, for “green” power company Verdant Power, as the East River fights Verdant’s bid to harness its currents (tides, really) for electricity:
North of the bridge, black cables snake out of the churning surface of the East River. They connect a makeshift control room inside an old shipping container on the island to a battery of futuristic mechanisms that could shape an energy future that does not pollute or use foreign oil — if a five-year-old company named Verdant Power can work out all the bugs.Weeks after they were formally dedicated by Mayor Michael R. Bloomberg, six underwater turbines that turn the river’s currents into electricity have been shut down for repairs and a basic redesign. The East River’s powerful tides have been wreaking havoc with the giant turbine blades since the first two were installed in December.
“But the good thing is that there’s more power in the East River than we thought,” said Mollie E. Gardner, a geologist for Verdant Power, which owns the equipment.
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It has been a rough eight months for Verdant. Days after the first two turbines were lowered into the water, the East River’s powerful currents sheared off the tips of several blades about a third of the way down.New blades were ordered, made of a cast aluminum that theoretically would hold up better. They replaced the ones that were broken, and were also installed on four more turbines that were lowered into the river’s eastern channel earlier this year.
Together, the turbines were capable of producing about 1,000 kilowatt hours a day of clean electricity. But the East River tides have proved too formidable even for the stronger blades, putting excessive strain on the bolts that hold them to the turbine hubs.
To keep them from coming apart, all six of the 20-foot-tall mechanisms, which resemble ship propellers on masts, have been shut down for repairs and may not be back in operation until November.
“The only way for us to learn is to get the turbines into the water and start breaking them,” said Trey Taylor, the habitually optimistic founder of Verdant Power.
Tide-mills have their advantages:
Hydro turbines have a few advantages over windmills. While winds are erratic, tides can be charted by the minute, which allows power companies to know exactly when the turbines will be generating power.