Impact of ambient turbulence on performance of a small wind turbine

High resolution measurements of wind speed and energy generation from an instrumented Bergey XL.1 small wind turbine were used to investigate the effect of ambient turbulence levels on wind turbine energy production. It was found that ambient turbulent intensity impacts energy production, but that the impact is different at different wind speeds. At low wind speeds, increased turbulence appeared to increase energy production from the turbine. However, at wind speeds near the turbine furling speed, elevated turbulence resulted in decreased energy production, likely to turbulent gusts initiating furling events. Investigation of measurements recorded at 1 Hz showed a time lag of one to 2 s between a change in wind speed and the resulting change in energy production. Transient changes in wind speed of only 1 s duration did not impact energy production, however, longer duration changes in wind speed were tracked reasonably well by energy production.

► Turbulence impacts on power output of a small wind turbine were directly measured.
► High turbulence at high wind speeds was associated with early furling.
► Higher turbulence at low wind speeds was associated with greater power output.
► Instantaneous turbine power output lagged changes in wind speed by one to 2 s.