"Dynamic soaring in wind turbine wakes"

[PierreB]

@dougselsam

Pierre, you were the one who said you thought the Dabiri idea of virtually lowering the height of existing wind turbines by placing vertical-axis turbines underneath, effectively raising the ground level to reduce windflow, and flying drone gliders between turbines on existing windfarms to somehow magically eliminate the fact that the first turbines in a series naturally get more energy, were both great ideas. You were the one who essentially equated both dumb ideas by saying they were both great ideas in the same sentence.

Your presentation is tendentious. My opinion about Dabiri’s concept was expressed:

@PierreB

Dabiri’s purpose is the optimization of a whole wind-farm, not VAWT as such even though he experimented them. Now, he studies HAWT by “pointing turbines slightly away from oncoming wind”.

It is about wake effect and optimization of a whole wind-farm, not about VAWT as such. Before, perhaps on the old forum, I calculated that these numerous small VAWT were uneconomic, but it is not the question.

It is funny that you praised John Dabiri’s work on:

Stanford Study verifies SuperTurbine(TM) Wake skew effect

https://nawindpower.com/stanford-researchers-boost-wind-productivity-with-wake-steering SuperTurbine™ is optimally oriented at a skew angle to the wind direction, with rotor skew thereby shunting each wake away from the succeeding rotor. Nice when the experts catch up with simple ideas. I remember hearing when I was a kid “Only the sun has planets.” I pondered how long it might take for “the smartest people in the world” to see what looked obvious to a little kid: If the sun has planets, oth…

The publication mentionning John Dabiri, and also your comment, are on your linked publication. I put again this link, and also two quotes (about John Dabiri’ statement and your comment):
https://nawindpower.com/stanford-researchers-boost-wind-productivity-with-wake-steering?utm_medium=email&utm_source=LNH+07-03-2019&utm_campaign=NAW+Latest+News+Headlines

“To meet global targets for renewable energy generation, we need to find ways to generate a lot more energy from existing wind farms,” says John Dabiri

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Selsam

4 years ago

This is what I’ve been explaining with regard to the line of rotors in a Selsam SuperTurbine™, offset from the wind direction to bring fresh wind to each rotor. The rotor skew directs the rotor wakes away from downwind rotors.

The wake effect and the optimization of a wind-farm has be discussed on this forum, for example on:

"Optimal size for wind farms is revealed by computational study"

It is well known that the efficiencies of turbines in a wind farm can be significantly lower than that of a single turbine on its own. While small wind farms can achieve a power density of over 10 W/m2, this can drop to a little as 1 W/m2 in very large installations The first law of thermodynamics dictates that turbines must reduce the energy of the wind that has passed through them. However, turbines also inject turbulence into the flow, which can make it more difficult for downstream turbin…

“…this can drop to a little as 1 W/m² in very large installations” could justify the purpose of the currently discussed study.