Airborne Wind Energy

Oliver Tulloch

Hong Yue ( Academic Supervisor )

Roderick Read ( Industrial Supervisor )

Windswept and Interesting

An early Daisy Kite prototype

Project Overview

Airborne wind energy uses tethered wings to harness the energy in the wind. By using lightweight materials airborne wind energy systems aim to reduce the cost of wind energy and reach locations not suitable for current wind turbines. This PhD focused on the airborne wind energy system being developed by Windswept and Interesting Ltd, the Daisy Kite.

The Daisy Kite uses a network of wings to form a flying rotor. The torque produced by the rotor is transmitted to the ground-based generator using a cylindrical network of tethers. This novel method of power transmission ensures that the airborne components are very lightweight and allows for continuous power generation which is rare within airborne wind energy. Through mathematical modelling and experimental tests this PhD analysed the entire system design with a particular focus on the power transmission.

Research prototype used during early experimental tests

Why Strathclyde

The University of Strathclyde is the best research institute at which this research project could have taken place. Within the Electronic and Electrical Engineering department the Wind Energy and Control centre has a wealth of expertise on all aspects of wind energy systems. Strathclyde is one of the few UK research institutes to have been actively investigating airborne wind energy for several years. Windswept and Interesting’s system, the Daisy Kite, shares aspects with both wind turbines and other airborne wind energy designs. Therefore, the knowledge within the Wind Energy and Control centre on both wind turbine technology and airborne wind systems provided the ideal research location for this project to take place.

Diagram of the Daisy Kite system

Researcher Impact

The collaboration with Windswept and Interesting has been crucial to the success of this research. Their contribution to the experimental aspects of the research has been essential. They manufactured all the prototypes that were tested during the project and all experimental tests were carried out at their test site on the Isle of Lewis. There were regular trips to their facilities based on the island to conduct the field tests.

Windswept and Interesting also provided valuable expertise on airborne wind energy. There were countless discussions with them regarding the direction of the modelling work and the operational aspects that were most important to incorporate into the mathematical representations. Without the constant support from Windswept and Interesting this PhD project would not have been possible.

Research prototype used during later experimental tests

Business Impact

Coordination with University of Strathclyde was easy. This helped us develop prototypes with the right capabilities to inform key performance insights. The university staff all did a fantastic job. They really seemed to enjoy the complexity of the challenges presented in this project.
Now we have a mathematical model which accurately describes this novel system. This model will be pivotal in enabling scaled deployments. We can now produce larger, more powerful systems with confidence in their operational safety and economic value.
The independent prototype analysis validated and verified claims the company had on system performance whilst also being able to recommend significant improvements in the system design.

Through the course of the PhD, our system efficiency was increased hugely. The series of practical tests also enabled us to quickly improve procedures and designs for better handling and robustness. With the vital knowledge gained from University of Strathclyde analysis we have been able to secure significantly more funding for further enhanced systems development.