In 2023, Kitepower flew a 176-pound fabric wing over a Mayo bog for the first time. 3 years later, it has logged more than 90 flights and over 100 hours generating airborne wind-energy data

As countries look for new ways to generate renewable electricity, engineers are exploring technologies that can capture wind energy beyond the reach of conventional turbines. One such approach replaces the familiar tower and rotating blades with a lightweight flying wing connected to equipment on the ground. The concept aims to use stronger and more consistent winds at higher altitudes while keeping the machinery relatively light and transportable.

That idea is being tested on Ireland’s Atlantic coast, where Kitepower has been operating an airborne wind-energy system above peat bogland in County Mayo. The project is designed to gather real-world data and determine whether a tethered wing can reliably convert wind into useful electrical power.

How the Kitepower System Generates Electricity

The system does not rely on a traditional turbine rotor. Instead, a fabric wing flies through the air in a continuous figure-eight pattern. It travels crosswind at an angle that enables it to build speed, and that movement generates lift.


The flying component weighs 176 pounds. It remains linked to ground equipment on a rope, with the tether transferring the force produced by the wing to a mechanical system below.

As the wing accelerates through the air, the resulting lift creates a strong pulling force. The tether can exert between 5,500 and 8,800 pounds of force, resulting in a drum inside a steel ground unit to unwind. The rotating drum drives a generator and generates electricity.

This outward movement is called the reel out phase and lasts about 80 seconds.

Once the tether reaches the required length, the control pod beneath the wing changes its position. The wing then becomes almost limp, enabling a small motor to pull the line back toward the ground. Because the wing is no longer generating a strong pulling force, considerably less energy is required during this return stage.

After around 20 seconds, another flight cycle starts. The objective is to produce more electricity during the outward movement than is consumed while retracting the tether.

A Lightweight Flying Wing

The wing spans 645 square feet when placed flat on the ground. Despite that size, the complete airborne assembly, that includes sensors and the control pod, weighs 176 pounds.

Its structure combines an inflatable membrane with a framework consisting of twelve hollow fiberglass tubes connected by aluminum components. Fiberglass was selected instead of carbon fiber because it can flex while still carrying the needed loads.

The tether is made from Dyneema, a lightweight synthetic fiber with extremely high strength. As per the supplied project information, it is stronger than steel wire of the same thickness while weighing less than a tenth as much.

The Mayo Test Site

The project is situated outside Bangor Erris in County Mayo, in Atlantic-facing bogland chosen following an extensive search for an appropriate location. The site is billed as the world’s first designated airborne renewable energy test site.

Kitepower, a Dutch company spun out of Delft University of Technology, is working at the location with RWE and Mayo County Council.

The initial flight at the Mayo site took place in September 2023. During its first year of operation, the team recorded more than 90 flights and more than 100 hours of airborne operation, averaging around five flights per week.

The longest individual flight lasted 5 hours 45 minutes.

The system deployed at the site generates almost 30 kilowatts and is supported by a 336 kilowatt hour battery. The wing has also been flown beyond 1,300 feet.

Testing has continued, with the partnership extended for further work and a permanent crew now based beside the field.

Operating in Controlled Airspace

Flying a large tethered wing at altitude introduces challenges that conventional renewable-energy equipment generally does not face.

A wing operating at 1,150 feet enters airspace used by aircraft. Consequently, each flight requires authorization from aviation authorities under airspace rules that were established long before airborne wind-energy technology was developed.

Traditional wind turbines have benefited from decades of engineering development, particularly in areas such as bearings and mechanical reliability. By contrast, a fabric wing being actively steered through a figure-eight path in changing winds remains a young class of machine.

A researcher at University College Cork analyzing the technology estimates that airborne wind energy could make a meaningful contribution to the electricity grid sometime in the 2030s.

Potential for Remote Locations

Airborne wind energy has not yet reached commercial operation at large scale, and the wider offshore wind sector has also experienced projects and technologies that failed to progress.

However, the system could have potential in areas where conventional infrastructure is difficult to install. The supplied project information points to islands, polar stations, mine sites, disaster-relief camps, construction projects and remote outposts as possible applications.

Such regions often rely on diesel because transporting heavy renewable-energy infrastructure can be difficult. A containerized system offers a various logistical model: a container can arrive by truck and potentially be operating within a day.

Plans for Larger Airborne Systems

Kitepower's larger 100-kilowatt system is projected to produce 450 megawatt hours of electricity annually. The company estimates that amount could correspond to the electricity needs of roughly 150 European homes.

The system is also claimed to use up to 90 percent less material than a conventional installation with similar output.

Kitepower's approach therefore focuses not only on producing electricity but also on reducing the physical infrastructure required to access wind resources.

One cofounder has already sketched out the possibility of 500-kilowatt containerized kites as a future development.

Currently, the Mayo project remains a test of what airborne wind energy can achieve in real conditions. The wing, tether and ground generator are continuing to collect operational data, while the project works to establish whether a lightweight flying system can become a practical option for renewable power, particularly in places where conventional infrastructure is challenging to deploy.

Source: THE PULSE

FAQs:

Q1. What is airborne wind energy?

Airborne wind energy uses flying devices to capture wind and convert its movement into electricity. Unlike conventional turbines, the generation equipment can remain on the ground.

Q2. How does Kitepower’s wing generate electricity?

The wing flies through the air in repeated figure-eight patterns, creating strong pulling force on its tether. That force turns a drum connected to a generator.