A SCADA-Based Method for Estimating the Energy Improvement from Wind Turbine Retrofitting

Retrofitting of operating wind turbines has been spreading in the recent years in the wind energy industry, at the aim of optimizing the efficiency of wind kinetic energy conversion. This kind of interventions has material and labor costs and it is therefore fundamental to estimate realistically the production improvement. Further, the retrofitting of wind turbines sited in harsh environments, as for example complex terrain, might exacerbate the stressing conditions and therefore affect the residue lifetime. This work deals with a case of retrofitting: the testing ground is a multi-megawatt wind turbine from a wind farm sited in a very complex terrain. The blades have been optimized by installing vortex generators and passive flow control devices. A general method is proposed for estimating production upgrades from wind turbine retrofitting, basing on multivariate linear modeling of the power output of the upgraded wind turbine. Applying the model to the test case of interest, it arises that the upgrade increases the annual energy production of the wind turbine of an amount of the order of the 2%.