Underwater turbines off the Irish coast are tapping into a huge source of green energy - oceans.
Energy source: hydropower
Project type: a tidal power plant to harness energy from the sea
Plant capacity: 1.2 Megawatts
Project size : Supplying energy to a small town of around 10,000 residents
When you look at solar power plants or wind parks being set up today, it's easy to forget how long it actually took for large energy companies to invest in expanding such technologies. The proponents of tidal power are faced with a similar problem today.
There's little doubt that waves and tides contain so much energy that they could theoretically meet the entire world's energy needs. 70 percent of the Earth's surface is covered with water and scientists around the globe are experimenting with small hydropower facilities to generate electricity. Currently, there are some 150 projects that harness energy from the sea.
There are a variety of approaches. They range from buoys that harness energy from wave movements to osmosis power plants at the mouths of estuaries that use the differing salt content of sea and river water to generate energy. Even the different temperatures deep in the ocean and on the water surface have the potential to generate electricity through water pumps.
Tidal currents, in particular, contains vast amounts of energy – both on the open seas as well as near the coasts. In select coastal areas, tides are responsible for regularly strong currents – which provide the perfect conditions for a tidal power station.
One of the most promising facilities is operated by British company Marine Current Turbines in a bay in Northern Ireland. It's located between the villages of Strangford Lough and Portaferry where the tidal currents are especially aggressive.
With a capacity of 1.2 Megawatts, the commercially operated tidal power station is the first of its kind in the world. It works much like an inverted underwater windmill, with the flow of tidal currents driving the turbine. For the past two years, the plant has been reliably supplying a small town with electricity.
A film by Joachim Eggers (sp)