Wind farm cumulative induction zone effect and the impact on energy yield estimation

Abstract

The cumulative induction zone effect arising from the operation of multiple wind turbine generators and their interactions within a wind farm is investigated within the framework of computational fluid dynamics. A computational fluid dynamic model is benchmarked and validated against measured lidar data from an offshore wind farm. A range of wind farm array configurations are investigated and the results are used to advise adjustments relevant to wind farm energy production assessments. Based upon the offshore wind farm array configurations investigated, the outcomes indicate that the cumulative induction zone effect results in a reduction in the induction zone wind velocity of approximately 0.3–1.6%, with a corresponding reduction in energy yield of 0.4–1.2% depending on the wind farm configuration, the inflow wind velocity and the atmospheric stability conditions. In the case of larger wind farms, investigations to date indicate that the cumulative induction zone effect is more pronounced with the appropriate energy adjustment factor predicted to be increased by a factor of up to two. Additionally, wind farm configurations and wind speed distributions differing from those considered within this work may result in cumulative induction zone effect values outside those stated.