Wind Energy Science 

This paper investigates the opportunities and limits of two additional devices that improve the aerodynamic performance of wind turbine rotor blades. The objective of attaching these relatively small add-ons is the optimization of the annual energy production over a time period of at least 20 years by mitigating the effects of typical wear-out effects, such as the surface erosion of rotor blades. Hence, the study is a contribution to the reliable and long-term generation of renewable energy.

A brief summary of current regulations and recommendations for the serviceability limit state dimensioning of offshore monopile foundations in sand supporting wind turbines is given. Results from small scale model experiments are presented, discussed and compared to the findings of other research groups to contribute to a better understanding of the complex processes associated with the cyclic load-bearing behavior of piles and to the development of improved calculation approaches.

In this work, we study parks of large-scale airborne wind energy systems using a virtual flight simulator. The virtual flight simulator combines numerical techniques from flow simulation and kite control. Using advanced control algorithms, the systems can operate efficiently in the park despite turbulent flow conditions. For the three configurations considered in the study, we observe significant wake effects reducing the power yield of the parks.

Like young children without help, wind turbines are bad at sharing. Those that are first in line (most upstream) take all the fresh air leaving little for those downstream. This research shows how turbines can operate to share the wind resource better and what parameters are most important for optimizing this technique. Results indicate that power gains of 10 % can be achieved if upstream turbines are operated differently, which may help operators produce more wind power.