High altitude wind power, from the early days until today

Optimal Cross-Wind Towing and Power Generation with Tethered Kites

Non-powered flight vehicles such as kites can provide a means of transmitting wind energy from higher altitudes to the ground via tethers. Although there have been many proposals for systems to extract wind energy from higher altitudes, this paper focuses on the use of a light lifting body at the end of a tether to generate useful power. Two...

Towards Flight Testing of Remotely Controlled Surfkites for Wind Energy Generation

Non-powered flight vehicles such as kites can provide a means of transmitting wind energy from higher altitudes to the ground via tethers. Although there is increased world wide interest for systems to extract wind energy from higher altitudes with kites, research into kite properties such as the coefficients and the stability is limited. Such...

Flexible Tethered Kite with Moveable Attachment Points, Part I: Dynamics and Control

Tethered kite technology is one potential means of harnessing energy available in high altitude winds. In an efficient and practical system, the kite is required to fly in cyclic patterns that maximize net power produced per cycle. At the same time, the tether length must be controlled to ensure the system does not expend more energy than it...

Optimal Trajectories for Tethered Kite Mounted on a Vertical Axis Generator

Tethered kite technology promises the enable the efficient extraction of energy from high altitude winds. One possible concept for converting the wind energy into electricity is to generate useful work at the ground by using a tether. The tether is able to drive a generator in one of two ways: either the tether is wound and unwound, or the...

Modeling and control of a kite on a variable length flexible inelastic tether

Preliminary Design of the "Superbus"

The present paper presents the structural design of the Superbus. First the overall requirements are described and analyzed, with respect to loads (static and dynamic), stiffness and functional requirements. In order to fulfil the relative targets, two different solutions have been defined and analyzed in the preliminary design. From those, the...

Flexible Tethered Kite with Moveable Attachment Points, Part II: State and Wind Estimation

An inflatable wing using the principle of Tensairity

The paper describes the new concept Tensairity which can be used to significantly improve the load bearing capacity of inflatable wings. The basic principle of Tensairity is to use an inflatable structure to stabilize conventional compression and tension elements. So far, Tensairity has been mainly used in civil engineering application like roof...

Tethered "kiteplane" design for the Laddermill project

The Laddermill is an innovative concept for generating energy from wind using large kite-like wings on a tether. The wings are able to fly in both the regime of airplanes and kites. We therefore call these structures "kiteplanes". By providing a recurring motion with a large lift during ascending and a lower lift during descending, energy can be...

Design of a 100 MW laddermill for wind energy generation from 5 km altitude

This paper presents the design of a 100 MW Laddermill. The Laddermill is a novel concept to generate electricity from high altitude winds. The concept allows very large single unit powers. It generates electricity by pulling a rope from a generator, with lift generated by kites. For a 100 MW Laddermill 50 kites are distributed evenly in the top...

Design and testing of a remotely controlled surfkite for the Laddermill

This paper presents the design and testing of a remotely controlled surfkite for the Laddermill. The Laddermill is a novel concept to generate electricity from high altitude winds. It generates electricity by pulling a rope from a generator, with lift generated by kites. Part of the rope that is connected to the kites is wound around the...