While its launch date has been delayed, the plan to install the world’s biggest tidal turbine in Northern Ireland is still a go. When the project is up and running, it will be the first of its kind to produce electricity at commercial levels.

As for the turbines themselves, they look and work very much like wind power turbines. Each blade is 15 to 20 metres across and is mounted on an axis that attaches to a three-metre-wide pile driven into the seabed. Tide-driven currents will move the rotors at speeds of between 10 and 20 revolutions per minute, which the company claims is too slow to affect marine life.

Though the Strangford Lough tidal generator is intended purely as a demonstration project, there are plans to build farms of turbines in the future consisting of 10 to 20 pairs each.

And not to be outdone, Florida Atlantic University has plunged $5 million and seven years’ worth of study into a tidal energy project of their own that will see a specialized turbine installed in the north-flowing Gulf Stream - the planet’s largest, most energy-dense ocean current - to generate electricity.

The ultimate dream is to have 3,000 turbines, each 130 feet in diameter, working in underwater unison to power up to 50 percent of Florida.