Analytical method towards an optimal energetic and economical wind-energy converter

• We present and physically model an innovative wind-energy converter.
• We derive an energetic system quantity to evaluate the energetic system efficiency.
• We describe the system economically.
• We optimize the system under respect of energetic and economic aspects.

An innovative concept to convert wind energy in wind-rich ocean regions is presented and analyzed. This concept involves the operation of wind-propelled vessels equipped with hydrokinetic turbines so that the kinetic energy of the water flow relative to the hydrokinetic turbine is converted into electricity. This electric power then is used to split sea water electrolytically into hydrogen and oxygen. A currently missing upper limit of energy conversion of the proposed system is presented, which is based on axiomatic conversion laws. To ensure the requirement of economic profitability the energetic description is widened by an economic description. Normally, the technical analysis precedes the economic assessment of a system. In contrast, a holistic approach is presented which yields the techno-economic optimal design as a trade-off between energetic efficiency and economic profitability. For system optimization Pareto optimization is applied to obtain convergence of the energetic and economic system quantities. The Pareto-frontier, defined as the multitude of all optimal energetic and economical systems, is presented. The application of this analysis shows that typical sailboats with 50 m2 sail area operating in 10 m/s winds deliver a mechanical power output of about 13 kW and sailing ships with 3200 m2 produce about 1 MW.