PHASE 2: RETRACTION (SEE KITE B)
The wing must be retracted to its start position consuming the minimum amount of energy. The pitch of the wing is actively changed to minimise aerodynamic force and the kite exits the loop to be held static in an overhead position to be glided back towards the starting point. Line tension can easily be reduced by a factor of 10 or more, such that a net energy gain is achieved over the Generation/Retraction reciprocating cycle.
In our system, two kites fly in the same airspace as per the figure such that whilst one is generating power the other is being retracted; energy production is therefore constant and the alternator kept rotating near optimal speed.
By using asymmetric kites (our second patent filed) we are able to produce a very efficient wing that flies the circular path of the generation phase with very little energy required for actuating the wing control mechanism.
Key design features of the KPS technology include:
Consequently no external power conditioning is needed and several KPS systems can be linked together (daisy-chained), significantly reducing the cabling required.
To avoid this the KPS system can be detached from its mooring in under 1 hour and towed back to a safe haven using a small tug or work boat for the majority of maintenance. This in turn reduces repair time, maximises operational availability, also reduces the need for expensive vessels and reduces risk to personnel.
In an emergency situation, weather extreme or other requirement each KPS system can be shut down from full rated output with the kites docked at a safe height in less than one minute from full power generation.