Airborne Wind Energy. Power generation with kites

17 november 2021. 13.00 CEST


UC3M Aerospace Seminar – Airborne Wind Energy – Roland Schmehl
Prof. Roland Schmehl. Section Wind Energy, Faculty of Aerospace Engineering, Delft University of Technology

Airborne wind energy (AWE) is an emerging renewable energy technology that uses tethered flying devices. Some concepts combine onboard wind turbines with a conducting tether, while others convert the pulling power of the flying devices into electricity on the ground. Replacing the tower and foundation of conventional wind turbines by a lightweight tether anchored to a ground station substantially reduces the material consumption and allows for continuous adjustment of the harvesting altitude to the available wind resource. The decrease in installation cost and increase in capacity factor can potentially lead to a substantial reduction of the cost of wind energy. Wind at higher altitudes is also considered to be an energy resource that has not been exploited so far.

In a first part, this webinar will outline the fundamental working principles and a basic theory to describe the energy harvesting performance, using this to explore some of the technologies implemented by industry. In a second part, the widely adopted pumping AWE concept will be analyzed in more detail, both theoretically and experimentally, with the final goal to describe the performance of AWE systems arranged in wind parks. In a last part, current research challenges are outlined, with a focus on the activities at TU Delft.

Roland Schmehl

Roland Schmehl graduated in Mechanical Engineering in 1994 and received a PhD degree in 2003 from Karlsruhe University. He continued his research on computational modeling of multi-phase flows as post-doctoral research fellow and then as propulsion engineer at the European Space Agency, investigating, among others, a start-up anomaly of Ariane 5’s hypergolic upper stage engine. In 2005, he started as software architect with TNO Automotive Safety Solutions in Delft, developing a simulation tool for airbag deployment, and in 2009, joined the Faculty of Aerospace Engineering of Delft University of Technology as associate professor. Leading the pioneering Kite Power research group, he focusses on the multi-disciplinary challenges of airborne wind energy. From 2015 until 2018 he coordinated the Marie Skłodowska-Curie doctoral training network AWESCO and from 2015 until 2019 the “Fast Track to Innovation” project REACH, both funded by the European Union’s framework program Horizon 2020. In 2016, he co-founded with Johannes Peschel the university spin-off company Kitepower BV that develops a 100 kW kite power system. He has co-edited and edited two Springer books about the emerging technology (published 2013 and 2018), and since 2015 co-organizes the international Airborne Wind Energy Conference. He is member of the core team that established the International Energy Agency’s Wind Task 48 on airborne wind energy, launched in October 2021. He is author of 82 peer-reviewed scientific publications.

Figure 1: Classification of AWE systems.
Figure 2: The two basic conversion modes of AWE: lift power (crosswind operation & electricity generation with ground station) and drag power (crosswind operation & electricity generation on flying device).
Figure 3: Representative flight path computed with a dynamic system model.
Figure 4: A pioneering example for such a system is the kite power system of Delft University of Technology that was first operated in 2010.
Figure 5: Mechanical power output (left) and power curve (right) for the 20 kW technology demonstrator of TU Delft.
Figure 6: Future park of AWE systems for utility scale energy generation (credits: Florian Bauer, TUM).