Imagine dozens, maybe even hundreds, of towering turbines, spinning in concert to generate a steady, non-polluting supply of electricity for a city somewhere. The array looks almost like any other wind farm … only residents of the city can’t see it.

That’s because those turbines are below the surface of the city river, producing power from the continual flow of water downstream.

It’s called hydrokinetic power, and there’s a growing effort around the world to tap into it. After all, with nearly three-fourths of the Earth’s surface covered by water, much of which is in constant motion, it makes sense to try and put all that liquid energy to good use.

Easier said than done, though. For all the world’s hydrokinetic riches, a lot of obstacles stand in the way of harnessing that power. It’s not just the technology that’s a challenge, but the environment and the creatures that live in it. Sound, for example, travels a lot farther underwater than it does in the air, and many forms of marine life depend on their hearing not just to communicate but to survive. So the whole question of how noise from spinning underwater turbines might affect, say, whales, needs answering before we can cover the seafloor with energy-harvesting technology.

With all those concerns in mind, the US Federal Energy Regulatory Commission (FERC) created standards a few years back for how to test hydrokinetic technologies in real-world settings while having a minimal impact on the environment. Under those standards, pilot projects have to be small, short term and placed in environments shown to be non-sensitive after “appropriate” analysis. They also need to be removable on short notice and taken down at the end of the pilot period unless a new license is issued.

Earlier this week, FERC issued its first license for just such a pilot project.

Set to be installed in New York City’s East River, the Roosevelt Island Tidal Energy (RITE) project is designed to generate just over one megawatt of electricity from 30 turbines moving under the power of the river’s natural tidal currents. The project, being developed by a 12-year-old company called Verdant Power, will be tested over a licensing period of 10 years.

According to the company, the RITE pilot will be the “world’s first grid-connected array of tidal turbines.”

While it might be a first, expect many more to come. As of this month, FERC has issued preliminary permits for 100 feasibility studies, is reviewing three other license applications and expects another nine to be submitted in the near future.

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