Scientists from LLNL, University of Colorado at Boulder and the NREL have recently assessed the performance figures of a wind turbine producing energy on the East Coast, and found how power depends on atmospheric stability.
“The dependence of power on stability is clear, regardless of whether time periods are segregated by three-dimensional turbulence, turbulence intensity or wind shear,” said Sonia Wharton from the UC at Boulder.
Wharton and her colleague, Julie Lundquist, discovered that the difference in wind speed and direction over a relatively short distance in the atmosphere (also known as wind shear) plays an important role in the efficiency of a wind turbine.
They emphasized that their study could help wind farm operators better estimate how much power is generated. A correct estimation, though, requires wind forecasts to include atmospheric stability impact measurements.
By analyzing 80-meter high wind turbines over a year, the two also found out that more power could be extracted at night, when winds are stronger, and that there’s also less power during the cool season, while summer has the highs. This could be exemplified by considering the fact that windy summer days average 43 percent of the maximum generation capacity while summer nights peak at 67 percent.
“We found that wind turbines experienced stable, near-neutral and unstable conditions during the spring and summer,” Wharton said. “But daytime hours were almost always unstable or neutral while nights were strongly stable.”
Wind power is surely going to contribute a lot to the alternative energy mix that will eventually power the world. Studies such as Wharton and Lundquists’s are necessary in order to learn more about how winds behave in the presence of our high turbines and at the same time to contribute to the knowledge of building them with less environmental impact and higher energy production efficiency.