Tidal Power

What won’t work in North Carolina?

Scientists are focusing on three sources of renewable energy from the oceans: wind power, wave power, and harnessing of the energy of the Gulf Stream. All of them have tremendous potential as a source of energy. They also present major challenges. However, there is another ocean energy source that has already been ruled out: tidal power.

Basically, tidal power is a form of hydropower that converts the energy in the surge of waters during the rise and fall of the tides into useful forms of energy. Tidal power has great potential as a source of green energy because it is more reliable than wind and solar power. However, it is expensive to produce and there is a limited availability of sites with sufficient ranges between low and high tides as well as tidal flow.

Right now, there are only two commercial tidal power plants operating. One is in France and the other is in Canada.

With North Carolina’s vast coastline and numerous inlets, there were high hopes that tidal power might work here. But upon closer examination, it turns out the difference between high and low tide is only about three feet. That’s not a huge difference.

In addition, there is no area along the coast that offers a tidal stream - a fast-moving body of water created by tides. A good example of a tidal stream that can be harnessed for power generation is in New York City's East River. Not only does water flow in and out of the river according to the tides, but the water is compressed enough in the riverbed that it produces a current strong enough to turn turbines. After years of testing the concept, 34 turbines will be installed by 2015 and they will produce enough energy for 9500 homes.

Unfortunately, North Carolina doesn’t have anything quite like that.

By the way, North Carolina Sea Grant is co-sponsoring a conference on offshore energy on March 24-25, 2014 at UNC Wilmington’s Burney Center. Lisa Schiavinato, North Carolina Sea Grant’s law, policy and community development specialist, tells me the conference will not only discuss various types of renewable ocean energy, but also recent case law on the topic and how tapping those resources might affect coastal communities.

- Frank Graff

Frank Graff is a producer/reporter with UNC-TV, focusing on North Carolina Science Now, a weekly science series that airs Wednesdays, beginning in August 2013, as part of North Carolina Now on UNC-TV. In addition to producing these special segments, Frank will provide additional information related to his stories through this North Carolina Science Now Reporter's Blog!

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