Better Computer Models Needed for Mega Wind Farms

[FBaggins]

With wind power getting cheaper, wind farm developers are drawing up plans for farms an order of magnitude bigger than anything around today, some with more than 1,000 turbines. But there’s one big problem: the economics of wind farms depends on accurate predictions of power output, and it is far more difficult to model how such large wind farms will behave.

At the scale of several hundred to over a thousand wind turbines, simulating the interactions between so many wind turbines, in a range of different weather conditions, can be too complex for current computer models. The issue could have profound implications for the cost of wind power and its ability to scale up to replace large amounts of fossil fuel.


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With billions of dollars on the line, developers of the new, very large wind farms are taking extraordinary measures to try to predict power output. Construction on one proposed 1,000-turbine mega wind farm, the Chokecherry and Sierra Madre project at the Overland Trail ranch in Wyoming, is expected to begin next year.

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These sorts of findings can impact how wind turbines are arranged, especially in larger wind farms with many rows of turbines. Charles Meneveau, a professor of mechanical engineering at Johns Hopkins University, has developed models of the way very large wind farms disturb the air up to a kilometer above them. Based on some of his simulations, he’s shown that turbines should actually be placed twice as far apart as they usually are to get the most out of the wind. But he says his current models still can’t accurately predict very large wind farm performance—they look only at performance in average wind speeds, and wind turbine performance can vary greatly depending on differences in wind conditions, he says.


http://www.newfuelist.com/link/~7uwl

Twice as far apart essentially means four times as much land. A 10% underproduction (relative to model) is likely preferable.

I wonder to what extent the wake aligns with the height of the turbine (compared to horizontal spacing). Perhaps modest vertical staggering would have a bigger effect.