By far the largest and most controversial project contained in the Energy Department (DECC) consultation is the Cardiff-Weston Barrage. This would cost around £20.9 billion and generate 16.8 terawatts hours per year or some 5% of UK’s electricity consumption. It could save some 7.2 million tonnes of carbon dioxide a year.
There are two proposals for impoundments, each adjacent to shorelines of the estuary. The Fleming lagoon, on the Wel