One of probably the most highly effective forces on the planet is that which controls tides. Powered by the gravitational pull of the moon, these repetitive ebbs and flows are predictable and renewable. In the UK, which has 50% of Europe’s tidal sources, the potential is big. Nova Innovation has invented and put in underwater generators within the waters off the coast of Scotland, powering companies, ships, and houses since 2016. NCS’s Max Foster investigates.