A water turbine is installed in the East River (Dec...

A water turbine is installed in the East River (Dec 2006) Credit: Verdant Power Inc.

It may seem like a tiny spark in a city of glowing lights, but the approval of a license to generate and sell 1 megawatt of power from the currents of the East River is a historic event.

Until now, the goal of producing energy from tidal waters has been elusive, but the Roosevelt Island Tidal Energy project is a small but indispensable step toward producing 15 gigawatts nationally by 2030. It's also evidence that the Federal Energy Regulatory Commission is easing bureaucratic hurdles.

Last week, the commission approved the first commercial license to produce tidal energy. Verdant Power, a start-up firm, has already been producing energy, with underwater turbines capturing the swift flow of the East River and sending the electricity to a supermarket and parking garage on Roosevelt Island.

That effort demonstrated that the turbine blades were not a threat to fish, which just swam around them. Now, as it gradually submerges up to 30 turbines, the company will find out whether that larger array has a detrimental environmental impact. So this is a pilot license, but it does allow Verdant to sell power.

Verdant is working with the City of New York to make the world's greatest city greener. Mayor Michael Bloomberg wants the city to be a model of renewable energy projects, and he supports this one.

It will take time for tidal power to be a major part of the nation's energy portfolio, but this license shows that the tide is turning.