New windmill technology

From Silicon Graybeard's place:

"German physicist Albert Betz long ago (1909) calculated the maximum efficiency that a wind turbine could achieve, today called the Betz limit.  According to Betz's law, no turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind.  Those monstrous infrastructure-sized turbines that we've all seen achieve about 80% of the Betz limit, or about 47% of the energy in the wind.  But what about other shapes?  The Dutch firm Archimedes tried the shape they named themselves after, the expanding spiral Archimedes' screw that has been used for pumping water since Archimedes' time.  They claim an efficiency of 80% - not 80% of 59% - a true 80% of the energy in the wind.  But it's better than even that:
Marinus Mieremet, cofounder of Archimedes, puts it this way: "Generally speaking, there is a difference in pressure in front and behind of the rotor blades of a windmill. However, this is not the case with the Liam F1. The difference in pressure is created by the spatial figure in the spiral blade. This results in a much better performance. Even when the wind is blowing at an angle of 60 degrees into the rotor, it will start to spin. We do not require expensive software: Because of its conical shape, the wind turbine yaws itself automatically into the optimal wind direction. Just like a wind vane. And because the wind turbine encounters minimal resistance, it is virtually silent."