Ocean Harvesting Technologies AB was founded 2007 in Karlskrona, Sweden, to develop Wave Energy Converter (WEC) technology. The R&D has been focused on how to integrate energy storage in the power take-off (PTO) of WEC´s in order to smoothen captured power before the generator, and to improve the power capture performance. A WEC with a gravitational energy storage device was first developed, and this storage technology was then also developed for a system with central tower in an array with hydraulic collection of power from the WEC´s.
In 2017, OHT discovered the opportunity to use a flywheel in combination with an infinitely variable transmission (IVT) in the PTO, to provide unique and advanced force control features. The technology is similar to Kinetic Energy Recovery Systems (KERS) used in vehicles to recover brake energy.
In December 2017, OHT completed system design for the 500 kW Infinity WEC, using a very efficient and low weight ball screw actuation system to convert the slow and reciprocating motion of the buoy into a high-speed rotary input to the InfinityDrive PTO read more. A wave-to-wire model of the InfinityWEC has also been developed in WEC-Sim to analyze performance and load case with different control strategies, such as model predictive control with constraints on maximum force, velocity and stroke of the buoy.
OHT is now planning to build a half-scale Hardware-In-the-Loop (HIL) test rig for the WEC machinery to be tested by RISE in the SMART-Ocean and Test Site Skagerrak initiative. Once the design has been thoroughly tested and validated, the InfinityWEC machinery can be installed in a complete WEC system to be sea tested on the site.