The use of drones and kites has significantly increased in research activities looking into the generation of energy at high altitudes over 500 metres.
Recently a group of researchers from the Universidad Carlos III de Madrid (UC3M) developed new software aimed at the analysis of energy generation systems based on kites and drones. In a recently published scientific article in Applied Mathematical Modelling, the UC3M researchers have presented a novel flight simulator for AWES and the software used to study the behaviour of these systems while transforming the kinetic energy of the wind into useful electrical energy.
AWES technology is based on harvesting wind energy. A light tether and an aircraft (flexible giant kites or large drones) substitute the conventional expensive and heavy tower and rotor of a typical wind turbine. AWES use the tension force of the tether to move an electrical generator on the ground whereas, in fly generation scenarios, the electrical energy is produced by wind turbines on-board the aircraft and transmitted to the ground by a conductive tether. In both cases, AWES have lower material costs, are relatively less expensive to install and operate at high altitude over 500 metres in more intense and less intermittent winds. They also present a low visual impact and good portability making them suitable for producing energy in remote and difficult access areas.
Gonzalo Sánchez Arriaga, Ramón y Cajal research fellow at the department of Bioengineering and Aerospace Engineering at the UC3M says, “AWES are disruptive technologies that operate at high altitudes and generate electrical energy. They combine well-known disciplines from electrical engineering and aeronautics, such as the design of electric machines, aero-elasticity and control, with novel and non-conventional disciplines related to drones and tether dynamics.”
Mr. Ricardo Borobia Moreno, an aerospace engineer from the Flight Mechanics Area at the Spanish National Institute of Aerospace Technology (INTA) and a PhD student in the department of Bioengineering and Aerospace Engineering at UC3M says, “The simulator can be used to study the behaviour of AWES, optimise their design and find the trajectories maximizing the generation of energy.”
The researchers have developed a flight test-bed for AWES also. Several flights recorded data of the two kite-surf kites equipped with information like the position and speed of the kite, attack and sideslip angles, and tether tensions. Using these experimental data different software tools, such as the simulator and an estimator of the different parameters characterizing the state of the kite at each instant were validated. “The preparation of the test-bed has required a significant investment of time, effort and resources, but it has also raised the interest from a large number of our students. Besides research, the project has enriched our teaching activities, as many of them have carried out their undergraduate and master final projects on AWES”, commented Arriaga.
Notably the European Commission and private companies such as Google, among others have been taking initiative in lending financial support to the Airborne Wind Energy Systems (AWES) related research.