Sustainable power generation

Tidal turbines

There are two different ways to derive energy from the movement of the sea. The big one at the moment is through the use of tidal turbines submerged in the water but working essentially in the same way as wind turbines. The other, which we will feature next month, uses the movement of the waves through a relatively simple technology. There’s also Ocean Thermal Energy, which works on the same heat exchange principle as ground source heating for houses. But for now, let’s look at turbines that use the movement of the tides.

Tidal power is still fairly new. The world’s first tidal turbine was tested in 1994 in Loch Linnhe, but it’s now in the Museum of Scotland – this technology has been developing fast. We now have the Sound of Islay Tidal Project, being constructed in the fast-moving water between the islands of Islay and Jura. It consists of ten 1MW Hammerfest Strøm HS1000 Tidal Turbines which will be fully submerged on the seabed just south of Port Askaig. ScottishPower Renewables (SPR) claim that this Tidal Array, costing £40 million, will generate about 30GWh of electricity, providing energy for 5,000 homes, around double the number of houses on Islay and Jura.

The map shows the position of the turbines, in the narrows between the two islands.

How does it work?

Each turbine looks approximately like the picture on the left.

The numbers on the next picture show the system.