Trying to work out how close together you can pack turbines in an offshore wind farm is a vital engineering decision for the developers of offshore wind farms.
That’s because the turbine wake — the slower and turbulent air that has just passed through the turbine — can reduce the output of any downwind turbines. [bold, links added]
As turbines become bigger, their wakes become much larger, and so, over time, engineers have been advising larger and larger spacing (Figure 1).
But the engineering models are, well, models, and each time a new, larger generation of turbines is introduced, they enter terra incognita: a scenario that is outside the range of their calibration data.
Inevitably, they sometimes get it expensively wrong.
The Burbo Bank Extension wind farm is currently paying over 5% of its turnover to next-door Burbo Bank Windfarm in compensation for wake losses.
Now, an important new working paper from renewables consultants ArcVera is reporting that the wake effects behind the huge turbines that are now coming onstream are going to be much worse than previously thought.
The conventional engineering wisdom is that there will be a 10-15% loss of output for a turbine placed less than 2 km downwind of another.
ArcVera is suggesting that new wind farms could experience losses of as much as 25% at a distance of 10 km(!).
The paper is another model, so it too needs empirical validation, but if it’s right, the implications are very serious for wind farms coming on stream.
Turbines are going to have to be spaced much further apart, and wind farms are going to need to be further apart too.
This is just going to increase the cost of an inherently expensive technology still further. And taxpayers are going to foot the bill.
Read more at NZW
Let’s not be totally negative here. Off shore wind farms are not all bad …
They don’t produce the level of electricity promised, and it is really expensive, and they are still bird chomping machines, but they do create artificial reefs for fish. So there’s that. lol
One qualification to my earlier comment. Those are specs for onshore wind. My understanding is offshore generates at a higher percentage of plate capacity, perhaps as high as the 45-50% range. Given the enormous cost of offshore installation & the need (still) for “back up” generation to keep the grid stable, I’m wary that offshore wind is (or will ever be) anywhere near competitive with fossil fuels or modular nuclear as that technology is perfected over time…
Just trying to remember from when wind energy was first starting. When winds are very strong say, like a large winter storm don’t the fans need to be shut down?
Joseph, if I recall correctly, the range of wind speed the average turbine can turn is around 8 to 40+- MPH. You need the minimum to turn it and the max is dictated by safety constraints to not put excessive torque on the blades or assembly. So, not only are you limited by the “vagaries” of wind, you also have a limited operational range. That explains why you only get generation about 30% on any given day. As Barry points out in the first comment, that necessitates conventional (thermal) generation to back up the intermittent source 70% of the time. Not an efficient way to generate electricity & keep a grid stable…
The most expensive thing about wind remains that it requires 100% backup from conventional hydro, nuclear, or fossil fuels (the only green energy). Solar and wind are useful in mobile applications. They have no practical use on the grid. Anywhere. The stupidity of politicians and other non-experts in calling wind or solar “green” is sheer ignorance of the environment. And sheer ignorance of practical facts of energy. Not a love for either.
The stupidest move made by our leaders is to decommission / dismantle the existing generators needed for back – up. Ontario has scrapped 3 coal-fired generating stations in the last decade or so. Ontario can get away with it by importing electricity from our neighbours , like Quebec. Germany at one time had 17 nuclear generating stations. They’re now debating whether to shut down (permanently) the last 3 stations in service in December!!! All the while begging the world for energy!
So do the Greens still want those things? If so then they have lost their interests in the Enviroment and have become stuck on a rediculous ideology based upon their own ignorance
Wind turbines get in each others way. That’s the only competitive thing about them.