By David Stewart
Taking advantage of the wind where it is strongest and most constant
What is Airborne Wind Energy?
We have all seen the proliferation of standard onshore and offshore wind turbines that convert the wind’s energy into electricity, and there has been a staggering reduction in the cost of electricity obtained from standard wind turbines so the question must be asked, is there something else out there that can drive down the cost further? The answer may well be an exciting technology being developed by several companies across the world called Airborne Wind Energy (AWE). AWE is like standard wind turbines in that it converts the wind’s energy to electricity, but there are some significant differences that make AWE very attractive.
An AWE system consists of 3 fundamental systems; a kite which is flown across the sky to collect the wind’s energy; a means of converting the kite’s motion to electricity; and a tether which connects the kite to a ground-based winch. During normal operations the kites will fly autonomously and land only for maintenance, or if wind conditions are not suitable.
Benefits of AWE
There would be no reason to develop AWE unless the cost of electricity could be driven down even further than current solutions on the market. As the kites fly at heights greater than standard wind turbines, where the wind is stronger and more consistent, the availability of the system is increased. There are areas of the world where standard wind turbines cannot be sited due to lack of wind resource, but these would be accessible to AWE systems.
AWE systems do not require large towers to access these higher, more consistent winds, nor do they need significant foundations to stop the large towers from toppling over. This significantly reduces the costs involved in deploying these systems. Due to their small footprint and relatively low mass, AWE systems are easily and rapidly transportable; additionally, they could be deployed in deep water offshore environments as they would be well suited to floating platforms.
AWE systems have significantly reduced operational costs compared to other forms of renewable energy, as the entire plant can be accessed from the ground without the need for specialist lifting equipment.
The fact that AWE systems can capture more of the wind’s energy, and are cheaper to install and maintain, means that the price of electricity is lower than for all other forms of energy.
Vision of KPS
KPS wants to ensure that AWE systems are a key component of the World’s energy mix. KPS’ systems can supply electricity to any location in the World through highly transportable systems, and much larger utility-scale systems which can be in any offshore environment.
Strategy of KPS
KPS is developing a highly transportable 500 kW onshore product which will become commercially available in 2025. This system will be targeted at areas that cannot be served by standard wind turbines, either through a lack of wind resource or for topological reasons. The 500 kW system will be transported in a number of ISO containers without the need for specialist transport or assembly. The 500 kW system will generate revenue for KPS allowing it to develop the larger multi-MW systems that will be destined for the offshore market.
All of KPS’ activities ensure that its developments feed into a coherent technology roadmap. KPS’ technologies are scalable, with many of them working more efficiently at the larger scale.
Image: KPS Airborne Wind Turbine Technology
Progress to Date
KPS was established in 2011, and initially focused on the potential of flying soft fabric surf kites. These cheap and light systems allowed KPS to develop their capabilities. KPS have a continued commitment to maximising the amount of lightweight materials in its kite.
To aid development of its automated flight controllers, KPS makes use of a sub-scale system which includes a 5 m wide kite. KPS flies the system in Germany and in Scotland; watching these test flights is one of the most enjoyable experiences as an aerodynamicist!
Back in the office, KPS is currently designing its first prototype 500 kW system, which is expected to be operational by 2021. KPS is working with a superb supply chain who are fully engaged in delivering a fantastic new form of renewable energy.
Airborne Wind Energy is an exciting new form of renewable energy that promises to deliver the next step change in the reduction of electricity cost. KPS is at the forefront of this new technology and has purposely selected scalable technologies which will take KPS through to multi-MW systems.
David is the Director of Technology at KPS. David’s background is in aeronautical engineering and has worked on numerous aerospace and motorsport projects before changing his focus to renewable energy. David joined KPS 2017 and he is a Fellow of the Royal Aeronautical Society.