The problem

Wind is the cheapest renewable energy alternative for large scale electrical energy production nowadays. Wind energy is mainly extracted on-shore at low heights by wind turbines mounted on towers with a few dozen meters (50-120 m) and, despite the significant number, still growing, of wind farms, most of the existing wind energy remains unexploited since it is available at high altitudes and off-shore.

The wind at high altitudes has higher speed when compared against the wind near the ground and, more importantly, it is more stable and consistent. Increasing the height of the towers or the dimensions of the blades of wind turbines is not a viable solution since building such towers entails unsustainable costs. Thus, there is an urge to develop more efficient solutions that enable wind energy extraction at high altitudes and offshore, without increasing production costs, making wind power a cost-effective and eco-friendly solution.

source: Rockets to Sprockets

In search for innovative solutions for generating power from renewable energy, namely to extract wind energy at high altitudes, the University of Porto is starting the project UPWIND in the area of Airborne Wind Energy Systems.

  The concept

One of the most promising proposals within AWES projects involves a kite, similar to ones used in kitesurfing, connected to a generator using a cable. As the kite rises by the wind, the cable is reeled-out producing power. The cable is reeled-in when it reaches its maximum length and then the process restarts over again.

source: KitePower

For efficiency reasons, it is desirable that the kite follows a pre-defined path in space. Knowing the maximum power that can be extracted from the wind is obtained when the kite moves in a perpendicular direction, the optimal trajectory is periodic and it follows a pre-defined path.

  • Reel–out phase: Energy is generated when cable is unwind.
  • Reel–in phase: Power is consumed when coiling back the cable.

  The project

The idea of generating power with tethered wings flying at high speed in a cross wind direction has been first proposed by Miles Loyd in 1980. Since then, a great variety of proposals has been reported.

There are open research questions, involving challenging optimization and control issues. This project aims to contribute to answer some of these questions.

  • Identification, Modelling and Estimation of AWES
    • To provide a detailed modelling and identification of a kite generator system (KGS).
    • To apply moving horizon estimation techniques for KGS.
  • Optimization and Control of AWES
    • To implement advanced control techniques, such as MPC, which are important to guarantee that stability of the overall system is particularly challenging in nonholonomic systems such as the kite.
    • To apply recently developed adaptive mesh refinement techniques to solve the optimal control problem that will further accelerate the optimizers run time.
    • To employ optimal control techniques to ensure that the kite follows a pre-defined path and also to define such paths in a way that maximizes power output.
  • Multiple Kite Systems
    • To guarantee robustness of the overall system, namely colision advoidance.
    • To find the best layout for a set of kites in a given area.

  Project Funding

  • 02/SAICT/2017-31447-FCT-UPWIND
  • PTDC-EEI-AUT-2933-2014/16858-TOCATTA
  • UID/EEA/00147/2013/UID/IEEA/00147/006933–SYSTEC

  AWES Start-ups

To explore wind at high altitudes, a growing number of research groups in Europe and in the US have recently been proposing Airborne Wind Energy Systems (AWES), mainly using kites or rigid wing systems. In addition, a few spin-off and start-up companies in the subject are emerging.

KitePower, The Netherlands

Kitemill, Norway

KiteGen, Italy

Makani (Google X), USA

AmpyxPower, The Netherlands

enerKite, Germany

  Meet the Team

Project FCT-UPWIND team members:

Fernando Fontes (PI)
SYSTEC-ISR, University of Porto

Cláudio Monteiro (Co-PI)
University of Porto

Adriano Carvalho
University of Porto

Amélia Caldeira
SYSTEC-ISR, Polytechnic of Porto

Carlos Ramos
SYSTEC-ISR, University of Porto

Dalila Fontes
INESC-TEC, University of Porto

Fernando Lobo Pereira
SYSTEC-ISR, University of Porto

Luís Tiago Paiva
SYSTEC-ISR, University of Porto

Maria do Rosário de Pinho
SYSTEC-ISR, University of Porto

Paulo Lopes dos Santos
SYSTEC-ISR, University of Porto

Sujit Baliyarasimhuni
SYSTEC-ISR, University of Porto

Teresa Perdicoúlis
UTAD
See also TOCCATA team members and SYSTEC team members .

  Students

Gonçalo Silva
MSc (2018)

Manuel Fernandes
MSc (2018)
PhD Candidate

Tiago Maia
MSc (2014)

  Open Positions

  Doctoral Researcher

We are hiring!
If you have a PhD in Engineering, Applied Mathematics or Computer Science and would like to work for the next 30 months in Airborne Wind Energy, at University of Porto, within this project, contact us and check and the full details of the call below.

  2019/02/08 - Call for Applications
Call status: CLOSED [open until April 11 at 12PM (Lisbon time)]
Full information at Eracareers.pt.

  PhD Scholarships (BD)

  To be opened soon.

  Scientific Initiation Studentship (BIC)

  2018/02/19 - Call for Applications
Call status: CLOSED [open until March 16 at 12PM (Lisbon time)]
Full information at Eracareers.pt.

  2018/02/15 - Call for Applications
Call status: CLOSED [open until March 5 at 12PM (Lisbon time)]
Full information at Eracareers.pt.

  Publications

Selected Team Publications -

[14] Manuel C.R.M. Fernandes, Gonçalo B. Silva, Luís Tiago Paiva and Fernando A.C.C. Fontes. A Trajectory Controller for Kite Power Systems with Wind Gust Handling Capabilities, in Proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics (ICINCO), Porto, Portugal, July 2018.

[13] Gonçalo B. Silva. Airborne Wind Energy Systems: Modelling, Simulation and Trajectory Control, MSc thesis, MSc in Electrical and Computer Engineering, Univ. Porto 2018. (Supervisors: Fernando A.C.C. Fontes and Luís Tiago Paiva).

[12] Manuel C.R.M. Fernandes. Airborne Wind Energy Systems: Modelling, Simulation and Economic Analysis, MSc thesis, MSc in Electrical and Computer Engineering, Univ. Porto 2018. (Supervisors: Fernando A.C.C. Fontes and Luís Tiago Paiva).

[11] Luís Tiago Paiva and Fernando A.C.C. Fontes. Optimal Electric Power Generation with Underwater Kite Systems. Computing, pp. 1-17, July 2018. (available online springer.com)

[10] Luís Tiago Paiva and Fernando A.C.C. Fontes. Optimal Control Algorithms with Adaptive Time-Mesh Refinement for Kite Power Systems. Energies, 11(3):475, February 2018.

[09] Luís Tiago Paiva and Fernando A.C.C. Fontes. Optimal Control of Kite Power Systems: Mesh-Refinement Strategies. Energy Procedia, 136, pp. 302–307, October 2017.

[08] Fernando A.C.C. Fontes and Luís Tiago Paiva. Guaranteed Collision Avoidance in Multi–Kite Power Systems. AWEC'17 - 2017 Airborne Wind Energy Conference, Freiburg, Germany, October 2017. (see the talk awec2017.com)

[07] Luís Tiago Paiva and Fernando A.C.C. Fontes. Optimal Control of Underwater Kite Power Systems [ BEST PAPER AWARD], in Proceedings of the IEEE Conference Energy and Sustainability in Small Developing Economies - ES2DE, Funchal, Madeira, July 2017.

[06] Fernando A.C.C. Fontes and Luís Tiago Paiva. Optimization–based control of constrained nonlinear systems with continuous–time models: Adaptive time–grid refinement algorithms, in AIP Conference Proceedings, 1776 (1), pp. 090009_1-090009_5, October 2016.

[05] Luís Tiago Paiva and Fernando A.C.C. Fontes. Adaptive Time-Mesh Refinement in Optimal Control Problems with State Constraints, Discrete and Continuous Dynamical Systems, 35 (9), pp. 4553-4572, 2015.

[04] Ionela Prodan, Sorin Olaru, Fernando A.C.C. Fontes, Fernando Lobo Pereira, João Borges de Sousa, Cristina Stoica Maniu and Silviu-Iulian Niculescu. Predictive Control for Path-Following. From Trajectory Generation to the Parametrization of the Discrete Tracking Sequences, in Developments in Model-Based Optimization and Control, Springer International Publishing, pp. 161-181, 2015.

[03] Luís Tiago Paiva and Fernando A.C.C. Fontes. Mesh–Refinement Strategies for Optimal Control of Kite Power Systems. AWEC'15 - 2015 Airborne Wind Energy Conference, Delft, Netherlands, June 2015.

[02] Luís Tiago Paiva, C. Veiga Rodrigues and J.M.L.M. Palma. Determining wind turbine power curves based on operating conditions, Wind Energy, 17 (10), pp. 1563–1575, 2014.

[01] Tiago C.M. Maia. Optimal control of power kites for wind power production, MSc thesis, MSc in Electrical and Computer Engineering, Univ. Porto 2014. (Supervisors: Fernando A.C.C. Fontes and Luís Tiago Paiva).

JOIN OUR RESEARCH GROUP!

Fernando Fontes

Project Coordinator
Associate Professor
University of Porto

Luís Tiago Paiva

Project Manager at the Lab
FCT Postdoctoral Fellow
University of Porto

To request information or send a general comment/question about this project, contact us by email.