Cold and grey with not much sun, the United Kingdom is rarely thought of as a pioneering hub of renewable energy innovation. However, the UK has thousands of miles of coastline, and new developments in underwater turbine technology could bring in a new wave of ocean harnessing power. A test project is currently underway in Scotland that could power up to 400,000 homes with power sourced from underwater turbines. Water is denser than air—by about 800 times—so smaller turbines underwater actually produce more power than their land based counter part.