BMW tries "motionless" wind tech on UK plant roof

Motionless to the environment and observers is the point here.

Fifteen years from now we’re going to have to make a new suffix to replace “less” because we’ve completely broken it. Maybe we could steal “sans” from the French. British writers use it very occasionally.

The picture in the article shows one turbine. In video reports of this and similar systems I’ve typically seen three or more of these all along the prevailing wind side of the roof. From a maintenance standpoint I would presume that 1) this works better on a building that is broadside to the wind, and 2) offering a discount for other potential customers in the vicinity of other customers would be cost effective once maintenance costs are included.