FAQ

Find all the answers

The most frequent questions on airborne wind energy are summarized here.

Frequently Asked Questions

You have further questions about our technology and products? We have summarized the most frequent questions here. If you can‘t find the information you are looking for, please don‘t hesitate to contact us

Operation

How much energy is consumed to rewind the tether?

SkySails Power Systems also make use of the wind’s power during the kite’s rewind phase: Once the tether has reached its maximum extension, the autopilot steers the kite into a neutral position with minor lift. In this upwind position, the wind’s power moves the kite towards the ground station. Depending on wind conditions, this consumes 5-10 % of the power produced during the power production phase. The process is developed and globally patented by SkySails.

Are there any unsuitable weather conditions?

The system can continue to operate in rain, snow, or hail. However, very heavy rain (e.g. monsoon), snowfall, or hail combined with comparatively little wind can make a landing necessary. The system cannot be used during thunderstorms. If thunderstorms are predicted, the kite will be landed for this event’s duration and then restarted.

What happens if there is no wind during operation? Will the kite crash?

If the wind suddenly stops, the winch rewinds the tether at high speed, creating an airflow on the kite sufficient to keep it flying. This way, the kite is safely landed. No human interaction is required for this process that is autonomously realized by the unit’s control system.

Can the kite fly at night?

Yes, the kite can operate 24/7. If required by air traffic regulations, the kite, the control pod, and the ground station can be marked with white flashing lights to improve visibility at night.

How much energy does the SkySails Power system generate?

The SKS PN-14 units have an average rated power of up to 200 kW, depending on site and wind conditions. Since the SkySails Power systems reliably generate power more than 75% of the year, they are an ideal solution to replace diesel generators.

Flying system (kite, control pod, tether)

What does the kite weigh?

The weight of the kite depends on its size. A 200 m² kite weighs about 50 kg.

Is the kite illuminated at night?

If required by air traffic regulations, the kite, the control pod, and the ground station can be marked with white flashing lights to improve visibility at night.

Compared to a conventional wind turbine, the kite is relatively small. How is this possible?

Because SkySails Power kites fly crosswind, they achieve very high inflow speeds. The current system achieves velocities that are five times higher than the wind speed. Because the tractive force is square to the inflow speed, SkySails Power kites reach forces that are 25 times greater than in static flight. Therefore, the aerodynamic area required to generate high power is tiny in relative terms. For comparison: In conventional wind turbines, the energy yield is mainly generated by the rotor’s relatively small blade tips. The blade tip speed is comparable to the kite’s inflow speed. However, the major part of the material expenditure lies in the “supporting structure” required to bring the blade tips into position.

What is the life expectancy of your system?

Most of the used components are standard industry commodities with high availability and track record sourced from experienced wind energy suppliers. For our kites, the use of modern UV coatings and extremely durable and innovative materials has significantly increased their lifespan. However, the kite and tether are wear parts that are replaced at regular intervals. This allows easy implementation of product optimizations that have a positive effect on yield production. Of course, these wear part’s costs are considered in the economic efficiency calculation of the project.

We are currently evaluating various upcycling or recycling options for used kites to optimize our systems’ ecological footprint. We are still open to creative ideas and potential partners. So do not hesitate to get in touch if you are looking for high-performance textiles for your creative business!

Ground station & foundation

What’s the height of the take-off and landing mast?

The launch and landing mast sits at the rear of the ground station. For the SKS PN-14, the tip of the mast is approximately 20m above the ground. Since the mast is only used for launching and landing and must only absorb minor mechanical loads, it is designed to be very slim and material-saving with little visual impact.

What are the requirements for the foundation of the system?

The foundation of a SkySails PN-14 is comparatively simple and cost-efficient. Unlike a conventional wind turbine, installing a SkySails Power system is done without a deep foundation and surface sealing. 120m² of subsoil must be stabilized with recycled material. Three pre-cast concrete plates of 2x2m and a depth of 0,4m are used to mount the tripod.