How green hydrogen could alleviate global water shortages, not exacerbate them

Green hydrogen will play a critical role in decarbonising the planet’s energy system, but a new report has suggested it could also prove crucial for addressing global water scarcity issues, which are only expected to deepen as the climate shifts.

According to a report published by the International Renewable Energy Agency (IRENA), technical green hydrogen potential sits at nearly 20 times the estimated global primary energy demand in 2050.

However, buried amidst the report is potentially important consideration for developers and countries planning large-scale hydrogen production projects – in particular around electrolysis, in which electricity is used to separate water into hydrogen and oxygen, and which requires significant water input.

The report suggests that in regions such as Africa, where water scarcity is becoming an ever more concerning challenge, green hydrogen production could help address these issues through the establishment of desalination plants, to supply both electrolysers and drinking water.

Typically, green hydrogen production is be done using local freshwater reserves, but the idea of combining desalination plants – which purifies sea water – is gaining traction as essential to future green hydrogen development.

In fact, according to IRENA, even for low levelised cost of hydrogen (LCOH) scenarios, “water supply, in the most conservative case, through desalination, represents only less than 4% of the total LCOH … which means it is relatively cheap when compared with the hydrogen supply.

“The water supply system could be expanded to cater for other water uses (e.g. sanitary) at a relatively small cost penalty for the hydrogen but providing the economies of scale needed to achieve low water costs.”

According to UNICEF, “Four billion people — almost two thirds of the world’s population — experience severe water scarcity for at least one month each year,” while “over two billion people live in countries where water supply is inadequate.”

Further, UNICEF predicts that half of the world’s population could be living in areas facing water scarcity by as early as 2025, and around 700 million could be displaced by intense water scarcity by 2030. By 2040, it gets even worse, with “roughly 1 in 4 children worldwide [expected to] be living in areas of extremely high water stress.”

Considering the increasing demand for green hydrogen and the expected role it will play in decarbonising the global energy system, combining hydrogen production facilities with desalination projects could serve as both added value for securing the financing needed to build green hydrogen projects, and as an incentive for governments and corporations to develop desalination plants.

Proximity to the coast is not necessarily a prerequisite, either, according to IRENA.

“Even in regions far from the coastline, water transport could be considered, which will increase the cost of water supply, but it will still represent a relatively small share of the total hydrogen production cost, reaching levels of USD 0.05/kgH2 and representing 1-2% of the energy consumption of the electrolyser.”