Turning the tides: Could hidden sea power energise UK coastal towns?

Image source, Flex Marine Power

Image caption, Engineer David Mummery says tidal power could change lives in coastal communities

ByPaul Hastie

BBC Scotland

In a secret location in the Highlands of Scotland, there's a fast-flowing river that's the key to understanding the massive power of water.

It's where engineer David Mummery found himself more than a decade ago.

With a length of cord tied tightly across the river, he swam out, gripped firmly, and let the unstoppable current rush over…