A preliminary analysis of the generation of hydrogen from a floating offshore wind system

Abstract

EU policy aims at reducing CO2 emissions into the atmosphere and at developing a low-carbon industry. One of the renewable electricity generation sources with a high development potential is offshore wind power. Green hydrogen production is also featuring prominently in the move towards decarbonisation of the industry sectors. This paper focuses on improving synergies between offshore renewables and co-located hydrogen production. Average annual wind speeds in the Mediterranean are lower than, for example, in the North Sea. The integration of intermediate energy storage between the wind turbines and offshore hydrogen (H2) production plants could reduce the intermittency of the electricity supplied to one of the key components; that is the electrolyser. Apart from reducing the number of start-ups and shutdowns of the H2 production plant, intermediate storage offers the opportunity to use smaller electrolysers working at a higher capacity factor. An example of such an intermediate energy storage device developed at the University of Malta and suitable for offshore use is the FLASC system. An offshore wind turbine coupled with a FLASC system can be connected to the hydrogen production plant offshore, close to the source of renewable generation. Such an offshore hydrogen production system would be based on the principle of water electrolysis. It would consist of seawater desalination and pre-treatment component, an electrolyser for direct hydrogen production, followed by compression and storage stages for subsequent use of H2 as a fuel in the maritime sector. Preliminary calculations show that Scenario 2b, which integrates the FLASC system with a 2-hour scheduling window, provides a reduction in the number of electrolyser On/Off cycles by 57% and an increase in hydrogen production of 2%, or 95.86 kNm3.