Before revision: History The exploration of offshore wind energy started with the introduction of Monopile foundations for wind turbines in a range from 1 up to 3MW in water depth of about 10 to 20m in the nineties last century .
After revision: History The exploration of offshore wind energy started with the introduction of monopile foundations for wind turbines in a range from 1 up to 3MW in water depth of about 10 to 20m during the 1990s .