Jacques, you are too nice, you could have said you have also the practical experience of what is building a windmill[0]. A very nice read for people enjoying both using a computer and their hands building stuff.
Is there any particular reason why that piece never uses the phrase "wind turbine"? That's actually what it is, right?
At the risk of stereotyping; because he's Dutch? :)
Because lay-people call them windmills.
You mean a real, practical, one bladed turbine like these guys? http://www.powerhousewind.co.nz/story.htm
Even though 12 blades are less efficient, the article points out that they may have advantages for the bigger system of a whole wind farm, availability of sites, production, transport, control and non-generating time. It's not beyond belief that all those other advantages could counteract the reduced efficiency. You can't really know from intuition unless someone actually studies it.
Another example - commercial aircraft are known to have a relatively inefficient shape, but that's cheaper to produce than the more complex and more aerodynamic alternatives even though they would reduce fuel costs.
It's significant that high-solidity turbines with many blades are in use. As you say, they're quite common in small-scale settings like water pumping.
An article purporting to 'discover' that design would probably be more shocking if it wasn't already in common use for sensible applications.
cool. I thought I had read in an issue of Popular Science or Discover magazine that one blade was theoretically the best but I don't know enough about it to say for sure.
you're probably thinking about a propeller - as in the type on an airplane or boat that puts energy into a fluid.
I'm not an expert but I'm pretty sure there is a big difference from a device trying to pull energy out of the fluid.
A quick google didn't lead me to an authoritative source, but I know I have read many times that a one-bladed propeller is the most efficient.
Re:Why Wind Turbines Have Three Blades
by cellularmitosis on Saturday May 07, 2016 @12:19AM
(#11648377)
Oh, I had thought an infinite number of infinitely thin blades got you the closest to Betz's limit?
Wouldn't that just be a disk?
If tower thump were not an issue then a one bladed turbine would be the best possible turbine (cost efficiency wise).
Further down he's even arguing for turbines with 12 blades, it's a ridiculous number and quite inefficient unless you want very high torque at low rpm such as for directly driving a mechanical waterpump.