Production of green hydrogen in Brazil for exportation from desalinated seawater using energy generated by heliothermal, photovoltaic, and wind plants

A current global trend is the production of green hydrogen via electrolysis of fresh water, preferably extracted from regions that have an abundance of renewable energy, to contribute to the mitigation of global warming. Despite being considered a source of fresh water, Brazil is experiencing a water crisis, with a shortage of water to meet agriculture and hydroelectric generation due to climate effects that affect the water cycle. With the forecast of increasing population and increasing demand for fresh water for consumption, agriculture, and industry, it is necessary to investigate opportunities for the generation of green hydrogen. This article presents results of technical and economic feasibility analyses of eight green hydrogen production systems for export, derived from two main concepts of seawater desalination plants aimed at preserving freshwater for other more noble purposes. All the analyzed systems use electrical and (or) thermal energy generation plants derived from solar and wind energy, with emphasis on heliothermal energy concentration systems. It is observed that the heliothermal systems, generators of electric and thermal energy, require higher investment costs; however, they have hydrogen production costs compatible with those of the other systems and dispatchable daily production of hydrogen and desalinated water. Furthermore, a system that combines thermal energy from a heliothermal plant to drive a thermal desalination plant and electrical energy from photovoltaic and wind plants to drive the electrolyzers was very well classified. Finally, it is verified that desalination plants have negligible investment cost compared to the cost of power and hydrogen plants.