Startup's new stunning kite can pull energy from the sky

The novel technology is less costly and takes up less land than a wind turbine.
Loukia Papadopoulos
Kite-powered wind energy.
Kite-powered wind energy.

kitecraft 

  • In this new technology called airborne wind, kites pull energy from the sky.
  • The tech is in its infancy.
  • It holds great promise for powering our future.

What if you could literally pull energy out of the sky? Several kite power companies are attempting to do just that, and they are succeeding.

The new technology, they say, comes with many advantages.

“It’s cheaper to manufacture, cheaper to transport, and also has higher efficiency,” tells Ars Technica Florian Bauer, co-CEO and chief technology officer of Kitekraft, a Munich-based company developing a kite power system. The carbon footprint is also much smaller, he says. “If you have all those advantages, why would anyone build a conventional wind turbine?”

How airborne wind works

How does the technology called airborne wind actually work? One such company, KiteMill, explains the process as a three-step approach:

1. The kite

The kite is a specially designed aircraft composed of composite materials. It has a rigid structure and is designed for durability in high-power winds. It has the form of a sailplane, and 4 propellers are only needed for taking off and landing. Once up in the air, the kite stays aloft by gliding seamlessly on air currents. The kite is designed to move quickly and effortlessly while adding a high tractive force on the tether.

2. The tether

The kite is connected to the ground through a tether. This tether transforms the pull force from the kite to the ground-station generator. It is made of braided polyethylene fibres chosen for their unique endurance capabilities. These, in turn, provide the lowest diameter for the tether; an essential factor for extracting energy from kite turbines. The material of the tether is durable and can be exposed to varying environmental conditions such as moisture and UV light.

Startup's new stunning kite can pull energy from the sky
Airborne wind shows great promise.
Kitecraft/YouTube 

3. The ground station

The ground station converts the tractive force from the tether to electricity. This electricity is, in turn, fed into the power grid. A winch in the ground station is connected to the generator, which reels in and out the kite. The control system is also found in the ground station and makes sure all flights are conducted safely and efficiently. It ensures optimal energy production as it controls the kite and the winch. Sensors mounted on the aircraft provide data points for the control system to steer and balance the aircraft. The control system enables the autonomous operation of Kitemill’s entire solution and the subsequent energy production.

How successful is this approach?

The company claims that their system can produce an average power of >1 hour of operation with continuous cycles at 5,5 kW.

Not yet sufficiently developed

The airborne wind is currently in its infancy, and if it wants to develop further, it will have to overcome many hurdles, such as proving that it is safe and reliable and does not cause any noise pollution.

Right now, none of the kite companies have produced energy in the megawatt scales required to compete with other renewable energy sources. This does not mean that they won’t.

The technology is based on sound scientific principles and holds much promise for the future. Could we soon all be powering our lives with kites?

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