Iberdrola's underwater energy project ready for next phase off Scottish coast

A joint project between Spanish giant Iberdrola and Scottish Power to harness underwater tidal energy has completed its initial test phase in the far north of Scotland.

The one-megawatt turbine is submerged off the coast of the Orkney island of Eday - a perfect area, according to Alan Mortimer, head of innovation at Scottish Power Renewables, "because the currents are very strong, the islands are close together and the depth is very good: around 45 meters."

With a 20-meter base and a propeller with a 10-meter radius, the Norwegian-made Hemmerfest HS 1000 turbine is already powering homes and businesses on Eday.

Following the success of the test, the Scottish government has given the go-ahead to install 10 similar turbines further southeast between the islands of Islay and Jura that would be capable of powering 5,000 homes. That project, considered the biggest of its kind in the world, will be an acid test for gauging the efficiency of wave energy. If successful, Iberdrola and other companies will be able to undertake an even bigger project to generate 1,600 megawatts (the equivalent of one-and-a-half nuclear reactors) in Pentland Firth, the strait between the Orkneys and mainland Scotland.

"The advantage over wind power is its predictability: you don't know when the wind will blow nor at what speed, but you know when and how big the tides are, which allows you to optimize the design and adapt it to the area where [it] will be installed," said Iberdrola's Álvaro Martínez.