CCS adds 20-90% more water consumption to power plants in water-scarce regions

Adding post-combustion carbon capture to a power plant increases water consumption by 20-90% per megawatt of electrical output, depending on cooling system design and capture technology. Amine-based CO2 absorption can require up to 106 cubic meters of cooling water per tonne of captured CO2. A 2020 study in Nature Sustainability found that 43% of the world's power plants where CCS could be deployed are located in regions already experiencing water scarcity. For these plants -- many in the American Southwest, Middle East, India, and northern China -- retrofitting CCS means competing with agriculture, drinking water, and ecosystems for a resource that is already overallocated. Power plant operators in water-stressed areas must either secure additional water rights (politically and legally fraught) or install expensive dry cooling systems that reduce capture efficiency. This creates a geographic paradox: many of the highest-emitting facilities where CCS would have the greatest climate impact are in precisely the places where it is most hydrologically constrained. The problem persists because CCS technology development has focused almost entirely on energy efficiency and cost-per-tonne, with water consumption treated as an externality rather than a binding constraint.