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
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
Our sustainable future is dependant on wind power, we're going to need a lot more of it, with bigger, more powerful turbines.
A lot of these can be built off shore where they aren't audible to humans anyway, but onshore is going to play a part too. The simple design change of a serrated trailing edge can dramatically improve the noise signature for those living nearby.
I wonder if it could easily be retrofitted to existing turbines.
4/4
@quixoticgeek Seems likely that it could be done via attrition: when it's time to replace the blades on a turbine, stick the quieter ones on instead.
Of course, that assumes they can be designed to be retro-compatible, but the principle of the thing seems sound.
@KatS Do they replace the turbine blades, or do they replace the whole turbine , nacel and support structure and all ?
@quixoticgeek Honestly, I really don't know.
I'm aware that various parts eventually need replacement due to wear and tear, but that's about as detailed as my knowledge gets.
I see where you're going, though: the more of the structure that needs replacing, the easier it would be to upgrade.
Apparently what we need here is a bigger geek :)
@quixoticgeek I went past a place in Goole that had one of these in a yard outside (I think they were a manufacturing place). Looked a bit like an enormous saw blade. Very impressive.
@quixoticgeek the blades with the feathered edges made a hissing sound rather than the normal thudding sound as they passed me.
Really surprising and impressive
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