Turbulence time scale equally important as intensity to wind turbine power generation

It is well known the intensity of incoming turbulent wind affects a wind turbine’s power generation. Previous models focused only on this parameter, but recent studies have highlighted the importance of another parameter: the turbulence time scale, or how rapidly the wind speed changes instantaneously.

Field studies cannot control atmospheric conditions. Stefano Gambuzza and Bharathram Ganapathisubramani are the first to experimentally confirm the conclusions of the field studies with a model wind turbine in a wind tunnel. They showed turbulence time scale affects power generation as much as intensity.

The authors subjected the wind turbine to flows with the same turbulence intensity at different time scale, as well as flows with different intensity at the same time scale. Measuring the power generated in each scenario, they found the effect of these two parameters are comparable. Both flows with larger turbulence intensity and flows with longer time scale yielded more power.

“The real importance of our work is that we have been able to fine-tune our incoming winds to separate the effects of these two parameters,” said Gambuzzaa. “We have experimental proof that the turbulence time scale cannot be overlooked while estimating the power output of a wind turbine in turbulent winds.”

The authors hope their results could be used to help determine where to install wind turbines to maximize power, as well as estimate how much power might be generated.

The turbine used in this experiment is much smaller than turbines in the field. Because turbine size affects how air flows across it, a next step for this research is to conduct the same study with a larger turbine.

Source: “The effects of free-stream turbulence on the performance of a model wind turbine,” by Stefano Gambuzzaa and Bharathram Ganapathisubramani, Journal of Renewable and Sustainable Energy (2021). The article can be accessed at https://aip.scitation.org/doi/full/10.1063/5.0039168 .

This paper is part of the Wind Tunnel Research, Dynamics, and Scaling for Wind Energy Collection, learn more here .