Quixotic wind turbines

Except, of course, Don Quixote tilted at windmills, and it was a different kind of tilt.

From RenewEconomy:

In a new paper published in the Proceedings of the National Academy of Sciences, Stanford University researchers have detailed a subtle, but effective technique for boosting the power output from wind farms by “steering” the wake created as the wind passes through a wind farm.

“To meet global targets for renewable energy generation, we need to find ways to generate a lot more energy from existing wind farms,” Stanford professor of civil and environmental engineering John Dabiri said.

“The traditional focus has been on the performance of individual turbines in a wind farm, but we need to instead start thinking about the farm as a whole, and not just as the sum of its parts.”

The researchers found that by tilting the wind turbines at a slight angle to the direction of the wind, it was possible to steer the wake of a wind turbine away from other turbines that are located downwind.

“To increase wind farm power production, we developed a wake steering control scheme. This approach maximizes the power of a wind farm through yaw misalignment that deflects wakes away from downstream turbines,” the paper says.

The wake from wind turbines disrupts of the flow of wind and can result in significantly lower power output from wind turbines located downwind.

The Stanford researchers developed a method of producing faster calculations for optimal “misalignment angles”, allowing for near real-time optimisation of the orientation of wind turbine blades, and tested the technique at an operational wind farm in Alberta, Canada.

The researchers collaborated with wind turbine operator TransAlta Renewables to test the methodology, finding that it was possible to boost output from the wind farm by up to 47 per cent during times of low wind conditions.

In normal wind conditions, the tilting technique was able to boost output by between and 7 and 13 per cent.

The results were highest for particular wind directions and provides the greatest benefit when turbines are aligned downwind of one another.

By providing less interrupted wind flows to wind turbines, the researchers were also able to reduce the level of variability of wind farm generation, improving the reliability and consistency of output from the wind. The researchers found that the level of variability in wind farm output could be reduced by as much as 72 per cent.

Technology tends to advance where it is needed most, or where it can make/save the most money.  Techniques which improve wind turbines, solar panels and batteries are being developed all the time, driving up efficiency and driving down costs.  It's part of the whole 'learning curve' process.