Last may @X31Andy came over to visit. Being a renewable energy geek, when I asked what he wanted to do for the day, he asked to go see some wind Turbines. By pure chance it was national wind mill open day, which gave us a crash course in 400 years of wind energy. Starting with a post mill, then a smock mill, before entering Flevopolder and visiting 3 generations of wind Turbine.
What amazed me most of tho was that the quietest of the turbines were the newest. 1/n
It was only when stood underneath the giant spinning turbine, that it was possible to see exactly why those wind turbines were so so much quieter than the slightly smaller, and also older generation turbines.
They had a serrated trailing edge. Like a row of teeth on a saw. This surprised me. I'd never seen this design feature before (yes I'm the sort of geek that's visited a few wind turbines in my time). But thinking about it, it makes a lot of sense.
2/n
The idea of the serrated trailing edge is borrowing from nature. The same way the feathers on the trailing edge of an owls wings have evolved to give owls near silent flight. The serrations on the trailing edge of the wind turbine blade dramatically reduces the noise signature of the turbine. It was genuinely impressive. Standing at the base if a spinning giant, and it being quieter than the cars driving by on the nearby road.
It's such a simple design change.
3/n
