摘要：The water intensity of the transitional hydrogen economy is analyzed by quantifying the
direct and indirect water requirements to annually manufacture 60 billion kg of hydrogen
partly by thermoelectrically powered electrolysis. It is determined that up to 143 billion
gallons of water would be directly consumed as a feedstock, with a total consumption
including evaporation of cooling water at power plants of 0.5–1.7 trillion gallons annually.
Total water withdrawals for thermoelectric cooling (most of which is not consumed) are
expected to increase by 27–97% from 195 000 million gallons/day today, depending
primarily on the aggregate efficiency of electrolyzers that will be in place and the portion of
hydrogen that is produced by thermoelectrically powered electrolysis. On a per unit
basis, thermoelectric power generation for electrolysis will on average withdraw
approximately 1100 gallons of cooling water and will consume 27 gallons of water as a
feedstock and coolant for every kilogram of hydrogen that is produced using an
electrolyzer that has an efficiency of 75%. Given that water withdrawals have
remained steady for decades, this increase in water use represents a significant
potential impact of the hydrogen economy on a critical resource, and is consequently
relevant to water resource planners. Thus, if minimizing the impact of water
resources is a priority and electrolysis becomes a widespread method of hydrogen
production, hydrogen production would need to be from hydrogen production
pathways that do not use much water (such as wind or solar), or effective water-free
cooling methods (e.g. air cooling) will need to be developed and widely deployed.
