Balancing the carbon and water footprints of the Ontario energy mix

With climate change being the current most pressing environmental issue, clean energy projects are emerging with a focus on reducing our carbon footprint while meeting our energy demands. There are several intersecting challenges surrounding climate change, energy demand, and water scarcity. The movement towards a less carbon-intensive energy supply could result in an increase or decrease in water demand, depending on the choice of technology. Ontario has made great progress in mitigating climate change by phasing out coal from their energy supply mix and further changes are expected over the next decade as the province shifts towards more renewable generation. This shift, however, will significantly increase the amount of water consumed to fuel demand. Carbon and water footprints for Ontario's energy supply mix, based on present day as well as on future projections, are presented. Cases studies illustrate how these footprints could change in likely, as well as extreme scenarios. Comparisons are also presented for California, where water scarcity is a more urgent concern. These findings stress the need for a balance between our water usage and carbon footprint and for a nexus approach to be in place to ensure a sustainable relationship between energy and water resources.