By Peter Hanlon
Originally published at Ecocentric.
When it comes to ocean power, wind turbines get all of the attention. But below the surface of the infamous East River, tidal turbines are getting ready to make a big statement in the Big Apple.
Back in 2006, Verdant Power started testing tidal-driven turbines in New York City’s East River. Since then, the company has installed six battle-tested turbines that have generated electricity for several nearby businesses.
Now Verdant wants to take the next step and build the nation’s first grid-tied, full-scale tidal power plant.
The company recently filed an application with federal regulators that would allow it to install up to 30 tidal turbines in the East River. The turbines would generate about 1 megawatt of electricity, representing just a fraction of New York State’s potential tidal power, estimated to be anywhere between 50 to 500 megawatts (PDF).
Most coastal cities are sited along estuaries (thanks to the transportation opportunities they provided back in the pre-planes, trains and automobile days), which are often ideal places for harnessing tidal power. Since the electricity-hungry population is right next to the source of energy, tidal power could also prove valuable to areas of the country that are having trouble meeting their energy demand, referred to as “transmission congestion.” Taking a look at a map of congested transmission lines in the Mid Atlantic, for example, reveals numerous coastal cities that could benefit from some locally-generated, renewable electricity. Finally, tides are incredibly easy to predict, unlike wind and sunshine, so New York City can bank on twice-daily power-generating tidal surges through the short and narrow East River.
The thought of turbine blades spinning underwater might raise concerns over the welfare of fish and other aquatic life, but it turns out that the East River turbines have been fish-friendly. Water is much denser than air, so tidal turbines can move slowly yet still generate as much energy as rapidly spinning wind turbine blades high above the water’s surface. That slow movement means that instead of entering a real-life bass-o-matic, fish have an easy target to avoid. In fact, while conducting a two-year study of the impacts of the tidal turbines on a surprising abundance of East River fish, analysts did not see a single instance of a fish being struck by a rotating blade. It turns out that the larger migrating fish simply avoid the blades, and smaller local fish only venture out from their shoreline nooks and crannies when the tides are changing – exactly when the currents are too slow to spin the blades.
Locally-generated renewable energy, and fish-friendly to boot — this is one power plant that I’ll be more than happy to call my neighbor.