Will water and land constraints affect electrolytic hydrogen production from renewables?

Large scale deployment of technologies for renewable hydrogen production might be limited by the availability of a sufficient amount of water and land. Some countries with high industrial activities and limited renewable resources might have to become importers of hydrogen or, conversely, exporters of industries that would rely on electrolytic hydrogen, according to new work led by iMMC PhD candidate Davide Tonelli recently published in Nature Communications. The work was the product of a collaboration with Lorenzo Rosa and Ken Caldeira of Carnegie Institution from Science, Alessandro Parente of ULB, and Francesco Contino of UCLouvain.
The question whether the future supply of hydrogen from water electrolysis will be limited by the lack of a sufficient amount of water has been raised many times. Based on their recent findings, despite the huge uncertainty around the future global demand of hydrogen by 2050, it can be concluded that water availability will not be a limitation, but it could lead to local concerns in the realization of hydrogen production plants which respect sustainability criteria of water use. If we only look at the total global supply of hydrogen, it will not require more than the 0.6% of the total global water available. This water demand is negligible at global scale, but it might have a local impact due to the uneven distribution of water and the future hydrogen production across countries.
Right now, hydrogen is mainly used in refineries and for the production of chemicals, relying on natural gas and coal. However, future scenarios indicate that its use will include the transport sector, industrial heat, and steel production. Depending on demand scenarios, there is a potential increase of hydrogen demand by more than 5 times by 2050 compared to the current use. In their work, Tonelli looked at the extreme situation in which the future hydrogen demand will be completely supplied by water electrolysis fed with renewable electricity from solar panels or wind turbines.

 
Their findings highlight that some countries, with an intense industrial production and a high population density, might be obliged to import hydrogen from abroad, if they want to maintain their industrial position. Countries with contemporary limitations of land and water resources for renewable hydrogen production include Trinidad and Tobago, South Korea, Dominican Republic, and Belgium. Other countries where the production of renewable hydrogen can be limited by available land for the installation of renewable technologies are Japan and the Netherlands.
Differently, some countries do not present any limitation in land and water to supply of renewable hydrogen. These countries could become future hydrogen exporters and are located in regions such as West and Central-East Africa, South America, Canada, and Australia. The installation of renewable hydrogen production plants in regions with abundant solar resources can compensate the need of renewable energy from highly industrialized countries.

 
Independently of hydrogen export, care should be paid to the specific location of installation of hydrogen production plants. Hydrogen supply to satisfy the national demand in regions in North Africa and Middle East could exacerbate the existing water scarcity by more than 5%. Measures to avoid any impact in terms of water use include the use of water desalination technologies for plants that can be located on the coast, with expected limited impact on the overall cost of production of hydrogen (<2%).

Related links :

• https://www.nature.com/articles/s41467-023-41107-x
• https://carnegiescience.edu/predicting-sustainability-future-hydrogen-economy