"Energizing a sustainable industry" - WITTENSTEIN alpha now sees the motto of this year's HANNOVER MESSE perfectly implemented on the high seas. In the form of smart gearboxes from the TPK+ series with cynapse functionality, as used by the start-up OCEANERGY AG on kite hydrogen ships to generate green hydrogen. When harvesting wind energy for the electrolysis of seawater directly on board, the power-dense, intelligent and communication-capable hypoid gearboxes perform important functions in controlling the four ropes of the kite propulsion system's sails, which are up to 1,200 meters long and around 60 square meters in size.

Wherever there is wind

With the robust TPK+ gearboxes and their cynapse functionality, i.e. with integrated sensors, logic and IO-Link data interface in the TPK+ gearboxes, OCEANERGY has deliberately opted for a reliable and future-proof technology. "The smart gearboxes will provide important operating and status data while the energy ships for producing green H2 in the six trade wind permanent wind zones of the world's oceans are intelligently navigated to wherever wind can be found," explains Ulrich Dobler, one of the board members of the Stuttgart-based start-up.

Eight-week 'harvesting tripʼ to produce around 1,000 tons of green hydrogen

As you might have guessed, the idea for the energy ships was inspired by the sport of kitesurfing, which is all the less surprising when you know that Dr. Wolfram Reiners, also a member of the OCEANERGY AG Management Board, is passionate about this hobby. "The basic idea was to convert the forces that occur on the kite sail and pull on the ropes when kiting into electrical energy," he says, looking back on the initial idea. At the heart of the Kite Hydrogen Ships concept is the patented K1 kite propulsion system, which serves as a green power socket for the electrolysis process on board. The task of the smart hypoid gearboxes is to control the kite's four frequency converter-controlled cables when they generate electrical energy when the sails are launched and during kite pumping during the harvesting run. The energy thus generated in the K1 kite propulsion system is used directly on board to a considerable extent to produce green hydrogen. "A hydrogen production plant of this kind is expected to generate around 1,000 tons of green hydrogen during its eight-week 'harvesting trip'," explains Ulrich Dobler. "That would be around 6,000 tons per year - a sufficient quantity to supply around 40,000 hydrogen-powered cars or to operate an Airbus for almost a year." The aim of the planned energy ship fleet is to produce green hydrogen at a cost of just 2 euros per kilogram by 2035 - and therefore significantly cheaper than is possible with all other known green technologies.

High load-bearing capacity with external forces

Based on simulation and application data, WITTENSTEIN's TPK+ series hypoid gearboxes were selected for the control and monitoring of the four wire rope hoists for kite pumping. Their angular design contributes significantly to the extremely space-saving implementation of the entire K1 kite drive system and its integration into a seaworthy container. The selected two-stage gearbox in size 300 with a gear ratio of i=100 is characterized by high torsional rigidity, low backlash and high load-bearing capacity with external forces. At the same time, the high-quality hypoid gearing ensures high torque and particularly smooth running.

Online gearbox monitoring on the high seas thanks to cynapse functionality

During the autonomous harvesting trips of the Kite Hydrogen Ships, the kites and therefore the main axis of the drive system will be exposed to extremely different movements and forces. OCEANERGY has therefore decided to equip the TPK+ with cynapse functionality. "This allows gearbox functions and operating data, such as acceleration values, to be monitored and analyzed remotely on the high seas," explains Felix Bartels, Head of Kite Propulsion Development.

Winch harvesting and WITTENSTEIN gearboxes - a perfect match

In addition to winch control with smart TPK+ gearboxes, OCEANERGY also solves other propulsion tasks on board the Kite Hydrogen Ships with gearboxes from WITTENSTEIN alpha. For example, the manual control unit of the K1 drive system features a low-backlash TP+ planetary gearbox from the alpha Advanced Line, a torque-tight and compact NVH worm gearbox from the V-Drive Value family and two TPM+ rotary servo actuators. The slewing ring uses a torque-tight and torsionally rigid XP+ planetary gearbox with a specially designed output and therefore an extremely compact, space-saving design.

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