From wave to jet and from jet to hydrogen: A promising hybrid system

• A promising hybrid prototype is presented consisting of a Blow-Jet and an electrolyser.
• The system stores the energy from waves in the form of hydrogen.
• The design conditions of the Blow-Jet were determined.
• The electrolysis current efficiency (ηI) found is around 90%.

One of the main challenges that our society must overcome in this century is that of finding alternative energy sources to fossil fuels. These, ideally, must be inexpensive, less polluting than current fuels and available for a substantial time. One promising alternative is hydrogen, which has the great advantage that it can be produced by coupling renewable energy devices with water electrolysis. Several projects devoted to connecting photovoltaic and wind systems with electrolysis devices have been successful; however, little research has been done into the coupling of ocean wave energy converters with water electrolysis. The work here proposes a basic system that stores the energy from waves in the form of hydrogen. The WEC considered is a novel design known as a Blow-Jet, which captures waves and converts them into a water jet. The performance of the Blow-Jet is found to depend more on wavelength than on wave height. The electrolyser results show, at 0.200 A and 1.88 V, that the electrolysis of water produces 0.082 Nl h−1 of hydrogen and a current efficiency (ηI) of 90.58%.