Underwater turbine spinning for 6 years is a breakthrough for tidal energy

Submerged in about 40 meters (44 yards) of water off Scotland's coast, a turbine has been spinning for more than six years to harness the power of ocean tides for electricity — a durability mark that demonstrates the technology's commercial viability.

- By JENNIFER MCDERMOTT

Keeping a large, or grid-scale, turbine in place in the harsh sea environment that long is a record that helps pave the way for bigger tidal energy farms and makes it far more appealing to investors, according to the trade association Ocean Energy Europe. Tidal energy projects would be prohibitively expensive if the turbines had to be taken out of the water for maintenance every couple of years.

Tidal energy technologies are still in the early days of their commercial development, but their potential for generating clean energy is big. According to the National Renewable Energy Laboratory, marine energy, a term researchers use to refer to power generated from tides, currents, waves or temperature changes, is the world’s largest untapped renewable energy resource.