Development of hydrostatic drive trains for wave energy converters

Hydrostatic drive trains are a promising power take-off technology in order to utilise the abundant wave power resource. The commercial success of wave energy devices depends significantly on the performance, efficiency and costs of their drive trains. The quantification and optimisation of these characteristics by means of numerical models is the subject of this work. The raised research question „How to design efficient hydrostatic drive trains for wave energy converters, how do they perform and what is their impact on the levelised costs of energy?“ leads to a techno-economic assessment of two-body heaving buoys and bottom hinged flap type converters. A method for the development and assessment is proposed and applied on four different drive train topologies. This thesis discusses how the hydrodynamic characteristics and control strategies of wave energy converters influence the choice of hydrostatic drive trains. The annual energy production of three wave energy devices including their hydrostatic drive trains is investigated. Besides the power and efficiency matrices, an overview of capital expenditures as well as levelised costs of energy for the assessed drive trains and grid connections is provided.