Airborne Wind Energy

Airborne Wind Energy

Tethers Menu

Computational Fluid Dynamics Lab

Dynamics and Control in Aerospace Systems

Plasma and Space Propulsion Team (EP2)

Aeroelastic and Structural Design Lab

Experimental Aerodynamics and Propusion Lab

Most wind energy systems, like wind turbines, extract power at low altitudes. Although extensive wind exploitation and remarkable growth happened thanks to conventional technologies, important benefits can be obtained by making the systems operate at high altitudes, where winds are stronger and less intermittent. In addition, the substitution of wind turbines by lightweight structures placed at a high altitude, such as kites, would reduce the costs and the visual impact. Airborne wind energy (AWE) systems are technologies that convert wind energy into electrical energy and are made of one or more aerial autonomous vehicles linked to the ground by at least one tether. These systems generate electricity by using the tether tension to move a generator on the ground (ground-generation) or using on-board wind turbines (fly-generation).

UC3M activities on AWE systems formally started in 2015 thanks to a Leonardo Grant funded by BBVA Foundation. From 2016 the team has performed research and development activities thanks to several projects granted by the Spanish Government: GreenKite (2016 – 2019), GreenKite-2 (2019 – 2023) and KITE2GRID (2023-2026). Additionally, UC3M AWE group has established a close collaboration with the Spanish company CT Ingenieros, through an Industrial PhD funded by Comunidad de Madrid, a Research Chair, and several joint research and development projects. In parallel, many Bachelor and Master Aerospace students developed their minor theses in our group, two PhD theses were defended since 2021 and two PhD theses are ongoing. UC3M research topics include the modelling, simulation and control of AWE systems, as well as the aerodynamic and aeroelastic characterization through numerical and experimental analysis. One of the most important results is the prototype of an AWE yo-yo machine.

Research capabilities

AWE Machine Prototype

Since 2015, UC3M has progressively acquired experimental capabilities on AWE systems. Starting from an experimental setup for the estimation of the aerodynamic parameters of AWE systems (DOIs: 10.2514/1.G003581 & 10.1002/we.2591), the group then developed an in-ground control system for power and rigid-framed kites and it is currently preparing a full prototype of a yo-yo AWE machine in collaboration with CT Ingenieros. Enabled by the multidisciplinary collaboration of the Aerospace Engineering Department and the Electrical Engineering Department of UC3M with CT Ingenieros, the prototype is designed to operate medium sized kites up to three lines, both connected to the grid and in islanded mode. The machine is a flexible and multi-purpose facility with application to the study of the dynamic and control of AWE systems, the mechanical-to-electrical power conversion, the optimization of on-ground and flying hardware and software elements and the aerodynamic characterization of AWE aircraft, among many others.

The AWE machine prototype is fully compatible with the experimental setup developed by UC3M to characterize the aerodynamic behavior of AWE systems. Fully compatible with 1, 2 and 3-line systems, the setup includes a mechanical control system with two linear actuators, a winch mechanism, inertial navigation unit with differential GNSS, a multihole pitot tube onboard the kite for the in-situ measurement of the full aerodynamic velocity vector, load cells at the tethers, and a weather station for measuring the wind velocity (modulus and direction). Dedicated estimation tools were also developed to fuse all measurements of the sensors and estimate the aerodynamic force and torque during in-flight testing campaigns and get the aerodynamic parameters by using estimation before modelling techniques.

Imagen Ground Station

The videos below show some of the in-flight tests that UC3M team carried out since 2015 with leading-edge inflatable and rigid-frame kites.

AWE simulator

UC3M has developed LAKSA, an open-source simulation package to study the dynamics and control of AWE systems (available for download). The software has 6 modules aimed at different machine architectures. The equations of motion for four of them were derived using a Lagrangian formulation with a minimal coordinate approach. This feature, along with the inelastic but flexible character of the tethers in the models, yields a non-stiff system of ordinary differential equations that is not coupled with algebraic constraints. As a result, the code is robust and efficient. LAKSA’s module, named KiteFlex, can be used to study both ground-generation and fly-generation systems. It considers the self-consistent dynamics of the aircraft (a rigid body), the on-board rotors, and a flexible tether. Its control vector, in the most sophisticated configuration, involves the length of the main tether for reel-in and reel-out operations, the lengths of the bridle lines, and the deflections of the ailerons, rudder, and elevator for steering the aircraft, as well as the torque of the motor controllers for the rotors. Thus, the code is prepared to analyze a wide variety of AWE machines, including those developed by companies such as Skysails, Kitepower, Mozaero, TwingTec, and Enerkite, among others. Recently, a new module called RAWE has been added, which can be used to study the dynamics of Rotary Airborne Wind Energy systems, such as the one developed by the company someAWE. All the simulators are linked to scientific articles that explain in detail the mathematical models and their structure (find links to them in the Publications section).

LAKSA

Computational Analysis of AWE Aerodynamics

An in-house three-dimensional unsteady panel method (DOI: 10.2514/6.2015-1185) and a high-fidelity open-source aerodynamic tool (SU2) have been applied to Rigid-Framed Delta (RFD) kites. This work opens the possibility to compare theoretical aerodynamic forces and moments to experimental ones (from flight-testing campaigns) for a deeper characterization and understanding of kites’ aerodynamics.

Computational aerodynamic characterization of kites
Research projects
  • Banco de ensayos en laboratorio de subsistema eléctrico de una máquina de generación de energía aerotransportada -KITE2GRID.
    Agencia Estatal de Investigación (Ministerio de Ciencia, Innovación y Universidades), 83.750€, PID2022-141520OB-I00, 2023-2026, PI: G. Sánchez-Arriaga, D. Santos-Martín
  • Ground-Actuated Airborne Wind Energy System Demonstrator (Industrial PhD – CT Ingenieros).
    Comunidad de Madrid (Consejería de Educación y Universidades), 135.000€.
    IND2022/AMB-23521, 2022-2025.
  • Desarrollo de sistemas de generación de energía con sistemas aerotransportados.
    CT Ingenieros, 2021-2022. PI: G. Sánchez-Arriaga
  • Modelling and flight testing of airborne wind energy and traction systems (GreenKite-2)
    Agencia Estatal de Investigación (Ministerio de Ciencia, Innovación y Universidades), 48.000€, PID2019-110146RB-I00, 2020-2023, PI: G. Sánchez-Arriaga
  • Simulation and Flight Testing of Power Kites Applied to Wind Energy Generation (GreenKite)
    Ministerio de Economía, Industria y Competitividad of Spain, 53.240€, ENE2015-69937-R, 2016-2019, PI: G. Sánchez-Arriaga
  • Leonardo Grant, Fundación BBVA, Generación Limpia de Energía con Cometas de Tracción
    Fundación BBVA, 40.000€, 2015-2016, PI: G. Sánchez-Arriaga
Publications
  • Unsteady Aerodynamics of Delta Kites for Airborne Wind Energy Under Dynamic Stall Conditions
    I. Castro-Fernández, R. Cavallaro, R. Schmehl, G. Sánchez-Arriaga (2024)
  • Dynamic analysis of the tensegrity structure of a rotary airborne wind energy machine
    G. Sánchez-Arriaga, A. Cerrillo-Vacas, D. Unterweger, C. Beaupoil (2024)
  • Automatic testbed with a visual motion tracking system for airborne wind energy applications
    I. Castro-Fernández, F. DeLosRíos-Navarrete, R. Borobia-Moreno, et al., Wind Energy (2023)
  • Flight trajectory optimization of Fly-Gen airborne wind energy systems through a harmonic balance method.
    F. Trevisi, I. Castro-Fernández, G. Pasquinelli, C. Riboldi, A. Croce, Wind Energy Science, (2022) 
  • Three-Dimensional Unsteady Aerodynamic Analysis of a Rigid-Framed Delta Kite Applied to Airborne Wind Energy
    I. Castro-Fernández, R. Borobia-Moreno, R. Cavallaro and G. Sánchez-Arriaga, Energies, (2021) 
  • Modeling and Natural Mode Analysis of Tethered Multi-Aircraft Systems
    G. Sánchez-Arriaga, J. A. Serrano-Iglesias, R. Leuthold and M. Diehl, Guidance, Control and Dynamics, (2021) 
  • Identification of kite aerodynamics using the estimation before modeling technique
    R. Borobia-Moreno, D. Ramiro-Rebollo, R. Schmehl and G. Sánchez-Arriaga, Wind Energy, (2021)
  • Activities and Roadmap on Airborne Wind Energy Systems at UC3M
    R. Borobia-Moreno, I. Castro, A. Pastor, H. Endo, C. Cobos, R. Cavallaro and G. Sánchez-Arriaga, Wind Energy (Japan Wind Energy Society), (2020) 
  • A lagrangian flight simulator for airborne wind energy systems
    G. Sanchez-Arriaga, A. Pastor-Rodríguez, M. Sanjurjo-Rivo, R. Schmehl, Applied Mathematical Modelling, (2019) 
  • Flight Path Reconstruction and Flight Test of Four-line Power Kites
    R. Borobia-Moreno, G. Sanchez-Arriaga, A. Serino, R. Schmehl, Journal of Guidance Control and Dynamics, (2018) 
  • A constraint-free flight simulator package for airborne wind energy systems
    G. Sanchez-Arriaga, A. Pastror-Rodríguez, R. Borobia-Moreno, R. Schmehl, Journal of Physics: Conference Series, (2018) 
  • Modeling and stability analysis of tethered kites at high-altitudes
    A. Pastror-Rodríguez, G. Sanchez-Arriaga, M. Sanjurjo-Rivo, American Institute of Aeronautics and Astronautics, (2017) 
  • Modeling and dynamics of a two-line kite
    G. Sanchez-Arriaga, M. García-Villalba, R. Schmehl, Applied Mathematical Modelling, (2017) 
  • A Kite model with bridle control for wind power generation
    J. Alonso and G. Sanchez-Arriaga, Journal of Aircraft, (2015) 
  • Flight dynamics and stability of kites in steady and unsteady wind conditions
    L. Salord and G. Sanchez-Arriaga, Journal of Aircraft, (2014) 
  • Dynamics and control of single-line kites
    G. Sanchez-Arriaga, The Aeronautical Journal, (2006)
Conference presentations
  • An Aircraft-Integrated Control System Based on Bridle Actuation for AWE
    Machines

    J. González-García, F. DeLosRíos-Navarrete, C. Nicolás-Martín, D. Santos-Martín and G. Sánchez-Arriaga. AWEC2024 (2024)
  • A Small-Scale and Multipurpose Airborne Wind Energy Prototype
    F. DeLosRíos-Navarrete, J. González-García, C. Nicolás-Martín, P. Egea-Hervás,
    D. Santos-Martín and G. Sánchez-Arriaga. AWEC2024 (2024)
  • Experimental validation of an airborne wind energy simulator based on a semi-empirical aerodynamic model
    F. DeLosRíos-Navarrete, I. Castro-Fernández, R. Cavallaro and G. Sánchez-Arriaga. WESC2023 (2023)
  • Multi-Fidelity Computational Aerodynamic Framework for the Static and Dynamic Behavior of Rigid-Framed Delta Kites for Airborne Wind Energy
    I. Castro-Fernández, R. Cavallaro, R. Schmehl and G. Sánchez-Arriaga, WESC2023 (2023)
  • Status of UC3M Testbed for the Aerodynamic Characterization of Kites Applied to Airborne Wind Energy Systems
    F. DeLosRíos-Navarrete, I. Castro-Fernández, M. Fernández-Jiménez, M. Zas-Bustingorri, A. Tarek-Ghobaissi, C. Cobos-Pérez and G. Sánchez-Arriaga,AWEC2021 (2022)
  • A Semi-Empirical Aerodynamic Model Based on Dynamic Stall for Rigid-Framed Delta Kites during Figure-of-Eight Maneuvers
    I. Castro-Fernández, R. Cavallaro, R. Schmehl and G. Sánchez-Arriaga, AWEC2021 (2022)
  • 3D Unsteady Aerodynamic Analysis of a Rigid-Framed Delta Kite applied to AWES
    I. Castro-Fernández, R. Borobia-Moreno, R. Cavallaro, G. Sánchez-Arriaga, Wind Energy Science Conference (WESC 2021), Hannover, (2021)
  • Flight Testing, Aerodynamic Parameter Identification and Dynamic Simulation of Rigid and Flexible Kites Applied to Airborne Wind Energy Systems
    R. Borobia-Moreno, D. Ramiro-Rebollo, G. Sánchez-Arriaga, R. Schmehl, Airborne Wind Energy Conference, Glasgow, (2019)
  • A Small-Scale Experimental Setup aimed at the aerodynamic parameter identification of flexible and rigid kites applied to airborne wind energy systems
    R. Borobia-Moreno, G. Sánchez-Arriaga, 7th European Conference on Renewable Energy Systems, Madrid, (2019)
  • Lagrangian and classical multi-drone dynamic simulators with application to airborne wind energy systems
    J. A. Serrano-Iglesias, G. Sánchez-Arriaga, 7th European Conference on Renewable Energy Systems, Madrid, (2019)
  • A constraint-free flight simulator package for airborne wind energy systems
    G. Sanchez-Arriaga, A. Pastor-Rodríguez, R. Borobia-Moreno, R. Schmehl, Torque2018, Milan, (2018)
  • Application of the Estimation Before Modelling (EBM) technique to the Aerodynamic Characterization of Power Kites
    R. Borobia-Moreno, G. Sanchez-Arriaga, R. Schmehl, Airborne Wind Energy Conference, Freiburg, (2017)
  • Determination of Optimal Control Laws in Airborne Wind Energy Scenarios With a Self-Consistent Kite Dynamics Model
    D. Expósito, M. Soler, G. Sanchez-Arriaga, Airborne Wind Energy Conference, Freiburg, (2017)
  • Experimental setup to study airborne wind energy generation using a train of kites
    H. Endo, K. Arakawa, G. Sanchez-Arriaga, H. Fujii, H. Okubo, Y. Takahashi, Airborne Wind Energy Conference, Freiburg, (2017)
  • Kite Flight Simulators Based on Minimal Coordinate Formulations
    G. Sanchez-Arriaga, A. Pastor-Rodríguez, M. García-Villalba, M. Sanjurjo-Rivo, R. Borobia-Moreno, R. Schmehl, Airborne Wind Energy Conference, Freiburg, (2017)
  • A low-cost experimental platform for airborne wind energy generation using kites
    H. Hendo, G. Sanchez-Arriaga, World Wind Energy Conference, Malmoe, (2017)
  • Flight Testing Setup for the Aerodynamic Characterisation of Power Kites Applied to Airborne Wind Energy Generation
    R. Borobia-Moreno, A. Serino, H. Hendo, G. Sanchez-Arriaga, World Wind Energy Conference, Malmoe, (2017)
  • Kite Flight Simulator
    G. Sanchez-Arriaga, AIAA Pegasus Student Conference, Toulouse, (2005)
PhD Theses
  • Design, manufacturing and testing of a Fly-Actuated yo-yo Airborne Wind Energy Demonstrator
    J. González-García. Directors: G. Sánchez-Arriaga and D. Santos-Martin. On-going Thesis
  • Ground-Actuated Airborne Wind Energy System Demonstrator
    F. DeLosRíos-Navarrete. Director: G. Sánchez-Arriaga. On-going Thesis
  • Unsteady Aerodynamics of Delta Kites applied to Airborne Wind Energy Systems
    I. Castro-Fernández. Directors: R. Cavallaro and G. Sánchez-Arriaga. (2024)
  • Aplication of Flight Testing Techniques to the Aerodynamic Charaterization of Power Kites
    R. Borobia-Moreno. Director: G. Sánchez-Arriaga. (2021)
Bachelor and Master Theses
  • Fluid-Structure Interaction Framework for a Rigid-Framed Delta Kite applied to Airborne Wind Energy
    A. Iboleón-Azcona. Director: I. Castro-Fernández, UC3M, (2023)
  • A Small-scale Prototype of an Automatic Control System Applied to the WindSled
    G. Bevilacqua-Giménez. Director: G. Sánchez-Arriaga, UC3M, (2023)
  • Stereo Vision and Kalman Filter Implementation for the closed-loop control of Airborne Wind Energy Systems.
    H. García-Cousillas. Director: I. Castro-Fernández, UC3M, (2022)
  • Control mechanical system and autopilot of an Airbone Wind Energy System.
    F. M. López-Vega. Director: G. Sánchez-Arriaga, UC3M, (2022)
  •  Design and Finite Element Analysis of a Rigid-Framed Delta Kite Applied to Airborne Wind Energy.
    M. Gisbert-Calvo. Director: I. Castro-Fernández, UC3M, (2022)
  • Readiness of a Mechanical Control System for Dual-Line Kites Applied to Airborne Wind Energy Systems
    M. Fernández-Jiménez. Director: I. Castro-Fernández, UC3M, (2021)
  • Real-Time Visual Motion Tracker for Airborne Wind Energy Systems Control
    M. Zas-Bustingorri. Director: I. Castro-Fernández, UC3M, (2021)
  • A Telemetry System Applied to a Small-Scale Airborne Wind Energy System
    A. Tarek Ghobaissi-González. Director: G. Sánchez-Arriaga, UC3M, (2021)
  • Robust Mechanical Control System for a Dual-Line Kite Applied to Airborne Wind Energy Systems
    S. Rashwan. Director: I. Castro-Fernández, UC3M, (2020)
  • Visual Motion Tracking for a Control System in an Airborne Wind Energy Application
    K. Best. Director: G. Sánchez-Arriaga, UC3M, (2020)
  • Flight Testing Rig for Airborne Wind Energy Systems
    D. Ramiro-Rebollo. Director: G. Sánchez-Arriaga, UC3M, (2019)
  • Design and Manufacturing of a Control System for a Dual-Line Kite
    M. Poole. Director: G. Sánchez-Arriaga, UC3M, (2018)
  • Design of a mechanical assembly for power kites automatic control
    A. Huerta, Director: G. Sánchez-Arriaga, UC3M, (2018)
  • Modeling and simulation of a train of kites
    J. A. Serrano, Director: G. Sánchez-Arriaga, UC3M, (2018)
  • Path Controller Implementation for Airborne Wind Energy Systems
    G. Escribano, Director: G. Sánchez-Arriaga, UC3M, (2018)
  • Control System and Hardware-related Elements Applied to Flight Testing of Airborne Wind Energy Systems
    A. Otero, Director: G. Sánchez-Arriaga, UC3M, (2018)
  • Flight Testing of Power Kites
    I. Martín, Director: G. Sánchez-Arriaga, UC3M, (2017)
  • Dynamics and control of acrobatic kites
    P. Muñoz, Director: G. Sánchez-Arriaga, UC3M, (2016)
  • On-board instruments and flight tests of giant kites applied to wind power generation
    A. Serino, Director: G. Sánchez-Arriaga, Politecnico de Torino, (2016)
  • Dinámica y Control de Cometas con bridas de geometría variable
    J. A. Pardo, Director: G. Sánchez-Arriaga, Politécnica de Madrid, (2014)
  • Dinámica y control de cometas de una línea
    L. Salord, Director: G. Sánchez-Arriaga, Politécnica de Madrid, (2013)

Contact

For further information please contact:

Gonzalo Sánchez Arriaga

Gonzalo Sánchez Arriaga

Full Professor
Office 7.1.H08 | Tel: +34 916248229
RT: Electrodynamic Tethers, Plasma Physics, Kite control and dynamics

Computational Fluid Dynamics Lab

Dynamics and Control in Aerospace Systems

Plasma and Space Propulsion Team (EP2)

Aeroelastic and Structural Design Lab

Experimental Aerodynamics and Propusion Lab