Scheduled to begin construction this year, the Swansea Bay Tidal Lagoon power plant will use the rise and fall of ocean tides to generate enough renewable electricity to power 155,000 homes for 120 years. When the structure is completed, it will produce enough electricity to displace more than a quarter million barrels of oil each year – while leaving virtually no carbon footprint.
The planned power plant uses a new method of harnessing the natural tidal forces – a nearly six-mile-long barrier wall that will enclose a huge amount of water in an artificial tidal lagoon. This lagoon captures and holds seawater at high tide. As the tide goes out, water in the 4.5 square mile lagoon will be as much as 27 feet higher than the water outside its walls. This immense pressure will be routed through 26 turbines, flooding out to sea until the water level equalizes on both sides of the lagoon. The flow is reversed at high tide, keeping the sea out of the lagoon until it reaches maximum height. Then water is let go, so it may rush through the turbines until it again fills up the lagoon.
The Swansea Bay Tidal Lagoon will not only produce clean energy, but will also be used as a sports arena, aquaculture farm to grow oysters, kelp, and other local sea crops, and a seaside sculpture garden. In addition, the lagoon can be used as an arena for sailing and cycling sports.
Its location at Swansea, Wales was chosen because it has some of the highest tide differences in the U.K. This will maximize the amount of water that can be used to turn turbines and generate the 420-gigawatt hours per year.
