Climate Change and Its Influence on Water Systems Increases the Cost of Electricity System Decarbonization
(a) Generating capacity built 2030 - 2050 under Baseline when climate change is ignored. (b) Cumulative change in capacity built 2030 – 2050 under climate scenarios. Black points indicate total net capacity change across all energy sources.
Image courtesy of authors.
This study examines how the Western US electric grid could proactively plan infrastructure buildout for climate change by 2050. As part of the work, the study evaluates climate impacts on water resources, since water is needed for hydropower generation and electricity for water provision. It finds that under most climate futures, because electricity use tends to increase while hydropower generation declines, the region may need to build up to 140 GW of extra generating capacity between 2030 and 2050, at an added cost of $150 billion.
These findings show that it is crucial to consider both water systems and climate change projections when planning future electrical grids. If studies do not carefully evaluate how climate change and water systems affect each other - and how they both impact electricity supply and demand - grid planners might underestimate how much and what type of generating or transmission capacity is needed, where it is needed, and what it will all cost. This could make it difficult to both achieve energy goals and meet electricity demands across the Western US.
This study quantifies the climate impacts that are expected to be most significant for the Western Interconnection 2030 - 2050 using climate projections of 15 Global Circulation Models. The analysis uses a detailed water resources model to evaluate hydropower potential and water-related electricity use from the Western US water system. The authors also estimate changes in electricity demand for building heating and cooling. Finally, the study uses a capacity expansion grid model to optimize the buildout and operations of generation and transmission by 2050, subject to the changes in demand and hydropower under the climate scenarios. The results compare the infrastructure buildout, dispatch, and cost of each climate scenario in the grid model against the Baseline Scenario wherein the Western Interconnection has a stationary climate.
The study finds that by 2050, cooling and water-related electricity demands increase in all climate scenarios, and hydropower generation decreases in the majority of cases. When these changes are less severe, the system adapts with more wind and transmission buildout, and when the impacts are greater, large increases in solar capacity alongside flexible resources, including battery storage and geothermal, take on a larger role.