An integrated assessment framework for the decarbonization of the electricity generation sector

The generation of electricity can have major environmental impacts not only in terms of greenhouse gas (GHG) emissions but also in terms of water use. There has been limited integrated assessment of the environmental footprints of deep decarbonization of electricity generation. This research develops an integrated approach to evaluate the GHG emission mitigation, water footprints, and marginal abatement costs of electricity generation decarbonization pathways. The decarbonization of Canada’s electricity sector was used as a case study. A Long-range Energy Alternative Planning model of the electricity generation sector was developed to determine future regional electricity generation technology mixes. A Water Evaluation and Planning model was also developed for the sector considering 530 power plants, 156 electricity generation water demand sites, and 74 major rivers. The energy and water-use models were integrated, and two scenarios were evaluated for a planning horizon of 2019–2050 using this integrated framework. The first scenario was based on current policy trajectories and the second was developed with a deep electricity decarbonization target of 100%. In the current policy scenario, water consumption and GHG emissions increased 22% and decreased 49%, respectively, by 2050 from 2019. The fully decarbonized scenario resulted in water consumption savings and negative marginal GHG abatement costs. The results quantify the co-benefits of decarbonizing electricity systems and show that transitioning toward renewables can reduce GHG emissions, water consumption, and system costs. These results may be important for policy development at the regional and national levels as well as internationally for jurisdictions looking to transition to carbon-free electricity.