It took a French-to-English translation of the
full story for me to comprehend what this is. It's the first horizontal windmill in France, they say. First one I've ever seen, too.
They're putting on top of a building where it will generate 9000 kW/h -- they don't say whether that's in top gear, or an average. Well, nothing else is going on, on top of most buildings, so why not take advantage and generate a bit of juice.
One interesting thought. The mill is one of the earliest ways that humanity captured energy for its own purposes. Designs for different types of mills are some of the earliest hard core engineering ever done. A tremendous amount of thought went into designing and building the things, over centuries of time. And yet, here is an innovation that only recently happened, due to the need to take advantage of different space with different demands.
There are always new things in the world, you know?