Report Suggests Plug-in Hybrids Threaten to Strain Freshwater Resources

Advanced technology vehicles are the wave of the future, but they aren’t the elegant solutions advocates posit them as. The conservation of one resource inevitably comes at the expense of another resource. A report by Carey W. King and Michael E. Webber of the University of Texas suggests that plug-in hybrid electric vehicles (PHEVs) will place a strain on the nation’s freshwater resources.

Chevy Volt 352The research compares miles driven with a conventional internal combustion engine vs. a PHEV. According to their findings, “In displacing gasoline miles with electric miles, approximately 3 times more water is consumed (0.32 versus 0.07–0.14 gallons/mile) and over 17 times more water is withdrawn.” In addition, “this increase in water usage presents a significant potential impact on regional water resources and should be considered when planning for a plugged-in automotive economy.”

To understand why these findings are significant, a short primer is necessary. As a physical substance, water is never “lost.” The hydrologic cycle ensures that the supply of water on Earth remains constant. Short of physically transporting H20 from the planet, water is a renewable resource. By contrast, oil is a finite resource. Once the supply of fossil fuels is exhausted, it’s gone forever. So why is the use of a renewable resource significant?

In short, all water is not equal. One type is vital to continued human existence- freshwater. In addition to drinking water, freshwater is a crucial ingredient in thermoelectric power plants, where it’s used as a coolant. Unfortunately, freshwater also happens to be the scarcest form of H20. Freshwater comprises just 3% of the world’s water supply, and about two-thirds of that is inaccessible in ice or permanent snow. According to the World Business Counsel for Sustainable Development, “The world is not ‘running out of water,’ but it is not always available when and where people need it.”

The increased operation of thermoelectric power plants to accommodate PHEV usage puts a significant strain on the freshwater supply. Despite King and Weber’s reassurances to the contrary, this fact is potentially detrimental to the widespread adoption of plug-in hybrids. At the very least, provisions will need to be made for the dramatic increase in freshwater demand.