Wind turbines offer a free source of electric power but they have had their share of problems. Particularly for those based in the sea, the support structure is complicated and expensive. World Wide Wind has an alternative that could change everything.
Their wind turbine uses are vertical axis and two counter-rotating sets of blades. The design puts most of the weight below sea level rather than at the top of a tall tower. At this point they have a prototype with plans for a a 3 megawatt model in 2026 and a 40 megawatt unit in 2029.
See New Atlas for more details.