Giant wind turbines are impressive and hypnotizing. They inspire by the possibility of generating enormous amounts of clean electricity, but engineers are confident that they can be made more productive.
Wind turbines have ceased to be exotic on both sides of the Atlantic and are now rarely seen singly: the green energy boom has prompted players in this market to create entire “farms” of hundreds or even thousands of wind turbines. In an effort to get as much electricity as possible, the installations are angled to capture wind in all directions, which creates an unexpected problem: the blades of neighboring wind turbines break the air flow and reduce the performance of subsequent installations.
The study, “Atmospheric Stability and the Ideal Performance Limit of Wind Farms,” published in the Journal of the American Physical Society, addresses this issue.
“It doesn’t make sense to add new turbines to an existing plot of land because at some point they start to cancel out the positive effects, and each turbine generates less energy,” the Cambridge engineers explain.
The main challenge in designing a wind farm is to ensure that each turbine has easy access to the high-speed airflow from which more electricity can be generated. Since the airflow above the wind turbines is much more powerful than between them, it is possible to increase the performance of the turbines by mixing these streams.
One option is to install a new type of turbine that has blades that rotate vertically rather than horizontally. Vertical wind turbines provide more powerful swirling of flows, especially if the blades of neighboring units rotate in opposite directions.
Thus, increasing the productivity of wind farms is possible not by increasing the number of turbines, but by optimizing their number, type and location in relation to each other and the landscape.
Now American scientists are planning to start testing their theoretical solutions in real conditions. The results of their research were published in the journal Physical Review Fluids.