UK tidal power has huge potential, say scientists

The analysis says that estuary barrages and tidal streams could provide more than 20% of the nation’s demand for electricity. Despite high costs, experts say tidal power is more reliable than wind.
The predictable nature of tides makes them an ideal renewable energy source, the journal Philosophical Transactions of the Royal Society A reports. But finding effective ways of utilising their latent power have proved elusive.
Essentially, engineers try to tap tides in two ways: one involves building barrages across tidal estuaries that use the ebb and flow of the waters to turn turbines – a major project of this type had been proposed for the River Severn.
The other method involves planting turbines underwater in fast flowing tidal streams in areas such as in coastal waters around Cornwall and Scotland. In the Royal Society report, researchers say they are "extremely optimistic" that both types of technology can be realised and relatively soon.