document

Efficiency of kite power systems in pumping operation

Fechner, U. (author), van der Vlugt, R. (author), Schmehl, R. (author), Ockels, W.J. (author)

Seminar organized by Delft University Wind energy research institute for European Academy of Wind Energy

conference paper 2011

document

The Economic Potential of Kite Power

Grete, C. (author)

The fundamental working principle of kite power generation is straightforward: a fast-flying kite pulls a tether from a drum, which drives a generator. At the maximum reel-out length, the kite is de-powered and pulled back, to initiate a new pumping cycle. The objective of this innovative technology is to make electricity generation affordable,...

journal article 2014

document

The International Airborne Wind Energy Conference 2015: Book of abstracts

Schmehl, R. (author)

Airborne wind energy is an emerging field in the renewable energy technologies that aims to replace the use of fossil fuels for energy production on an economical basis. A characteristic feature of the various concepts that are currently pursued is the use of tethered flying devices to access wind energy at higher altitudes where the wind is...

book 2015

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A Methodology for the Design of Kite-Power Control Systems

Fechner, U. (author)

doctoral thesis 2016

document

Warping model predictive control for application in control of a real airborne wind energy system

Lago, Jesus (author), Erhard, Michael (author), Diehl, Moritz (author)

Fast online generation of feasible and optimal reference trajectories is crucial in tracking model predictive control, especially for stability and optimality in presence of a time varying parameter. In this paper, in order to circumvent the operational efforts of handling a discrete set of precomputed trajectories and switching between them,...

journal article 2018

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Welcome and Introduction to the Airborne Wind Energy Conference 2019

Schmehl, R. (author), Tulloch, Oliver (author)

conference paper 2019

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Steady-State Solver for a Ram-Air Kite Aeroelastic Model Based on Dynamic Relaxation

Thedens, P. (author), Bungart, Merlin (author), Schmehl, R. (author)

We present a computationally efficient steady-state solution method to model the aeroelastic deformation of a ram-air kite for airborne wind energy applications. The kite’s weight in comparison to the aerodynamic forces is small which justifies a quasi-steady analysis, neglecting gravitational and inertial force effects [1]. The approach is...

abstract 2019

document

Improving reliability and safety of airborne wind energy systems

Salma, V. (author), Friedl, F. (author), Schmehl, R. (author)

Airborne wind energy systems use tethered flying devices to harvest wind energy beyond the height range accessible to tower-based wind turbines. Current commercial prototypes have reached power ratings of up to several hundred kilowatts, and companies are aiming at long-term operation in relevant environments. As consequence, system...

journal article 2019

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Quasi-steady model of a pumping kite power system

van der Vlugt, R. (author), Bley, A.C. (author), Noom, Michael (author), Schmehl, R. (author)

The traction force of a kite can be used to drive a cyclic motion for extracting wind energy from the atmosphere. This paper presents a novel quasi-steady modelling framework for predicting the power generated over a full pumping cycle. The cycle is divided into traction, retraction and transition phases, each described by an individual set...

journal article 2019

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Ram-air kite airfoil and reinforcements optimization for airborne wind energy applications

Thedens, P. (author), De Oliveira Andrade, G.L. (author), Schmehl, R. (author)

We present a multidisciplinary design optimization method for the profile and structural reinforcement layout of a ram‐air kite rib. The aim is to minimize the structural elastic energy and to maximize the traction power of a ram‐air kite used for airborne wind energy generation. Because of the large deformations occurring during flight, a fluid...

journal article 2019

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Airborne wind energy resource analysis

Bechtle, Philip (author), Schelbergen, M. (author), Schmehl, R. (author), Zillmann, Udo (author), Watson, S.J. (author)

We compare the available wind resources for conventional wind turbines and for airborne wind energy systems. Accessing higher altitudes and continuously adjusting the harvesting operation to the wind resource substantially increases the potential energy yield. The study is based on the ERA5 reanalysis data which covers a period of 7 years...

journal article 2019

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8th international Airborne Wind Energy Conference (AWEC 2019): Book of Abstracts

Airborne Wind Energy (AWE) is an emerging renewable energy technology that aims to replace the use of fossil fuels for energy production on an economical basis. A characteristic feature of the various AWE concepts is the use of tethered flying devices to access wind energy at higher altitudes where the wind is more consistent. Over the past...

book 2019

document

Adaptive flight path control of airborne wind energy systems

Dief, Tarek N. (author), Fechner, Uwe (author), Schmehl, R. (author), Yoshida, Shigeo (author), Rushdi, Mostafa A. (author)

In this paper, we applied a system identification algorithm and an adaptive controller to a simple kite system model to simulate crosswind flight maneuvers for airborne wind energy harvesting. The purpose of the system identification algorithm was to handle uncertainties related to a fluctuating wind speed and shape deformations of the...

journal article 2020

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Power Prediction of Airborne Wind Energy Systems Using Multivariate Machine Learning

Rushdi, Mostafa A. (author), Rushdi, Ahmad A. (author), Dief, Tarek N. (author), Halawa, Amr M. (author), Yoshida, Shigeo (author), Schmehl, R. (author)

Kites can be used to harvest wind energy at higher altitudes while using only a fraction of the material required for conventional wind turbines. In this work, we present the kite system of Kyushu University and demonstrate how experimental data can be used to train machine learning regression models. The system is designed for 7 kW traction...

journal article 2020

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Structural analysis and optimization of a tethered swept wing for airborne wind energy generation

Candade, A.A. (author), Ranneberg, Maximilian (author), Schmehl, R. (author)

In this paper, we present an aero-structural model of a tethered swept wing for airborne wind energy generation. The carbon composite wing has neither fuselage nor actuated aerodynamic control surfaces and is controlled entirely from the ground using three separate tethers. The computational model is efficient enough to be used for weight...

journal article 2020

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Towing test data set of the kyushu university kite system

Rushdi, Mostafa A. (author), Dief, Tarek N. (author), Yoshida, Shigeo (author), Schmehl, R. (author)

Kites can be used to harvest wind energy with substantially lower material and environmental footprints and a higher capacity factor than conventional wind turbines. In this paper, we present measurement data from seven individual tow tests with the kite system developed by Kyushu University. This system was designed for 7 kW traction power...

journal article 2020

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Combined Airborne Wind and Photovoltaic Energy System for Martian Habitats

Ouroumova, L.H. (author), Witte, D. (author), Klootwijk, B.J. (author), Terwindt, E.N. (author), van Marion, F. (author), Mordasov, D. (author), Corte Vargas, F. (author), Heidweiller, S. (author), Géczi, M. (author), Kempers, M.X. (author), Schmehl, R. (author)

Generating renewable energy on Mars is technologically challenging. Firstly, because, compared to Earth, key energy resources such as solar and wind are weak as a result of very low atmospheric pressure and low solar irradiation. Secondly, because of the harsh environmental conditions, the required high degree of automation, and the exceptional...

journal article 2021

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Electricity in the Air: Insights From Two Decades of Advanced Control Research and Experimental Flight Testing of Airborne Wind Energy Systems

Vermillion, Chris (author), Cobb, Mitchell (author), Fagiano, Lorenzo (author), Leuthold, Rachel (author), Diehl, Moritz (author), Smith, Roy S. (author), Wood, Tony A. (author), Rapp, S. (author), Schmehl, R. (author)

Airborne wind energy systems convert wind energy into electricity using tethered flying devices, typically flexible kites or aircraft. Replacing the tower and foundation of conventional wind turbines can substantially reduce the material use and, consequently, the cost of energy, while providing access to wind at higher altitudes. Because the...

review 2021

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Exploring design dominance in early stages of the dominance process: The case of airborne wind energy

van de Kaa, G. (author), Kamp, L.M. (author)

This paper is about Airborne Wind Energy Systems, a promising new wind power generating system that, although technologically possible to realize, is not available on the market yet. Currently, many different technological options for the systems are being developed. One question for such systems is where to position the generator, on the...

journal article 2021

document

Identification of kite aerodynamic characteristics using the estimation before modeling technique

Borobia-Moreno, R. (author), Ramiro-Rebollo, D. (author), Schmehl, R. (author), Sanchez Arriaga, G. (author)

The aerodynamic characteristics of a leading edge inflatable (LEI) kite and a rigid-framed delta (RFD) kite were investigated. Flight data were recorded by using an experimental setup that includes an inertial measurement unit, a GPS, a magnetometer, and a multi-hole Pitot tube onboard the kites, load cells at every tether, and a wind station...

journal article 2021