Effects of Climate Change on US Federal Hydropower Generation - CMIP6-based Assessment with Focus on Understanding the Uncertainty
Abstract
Understanding the future changes in projected water supplies is a vital objective for federal hydropower facilities tasked with providing low-cost, reliable electricity across a large regional footprint that encompasses a growing customer base, alternative market structures for marketing the electricity, and a more diverse generation asset mix. Driven by the SECURE Water Act Section 9505, this study evaluates the effects of climate change on hydroelectric energy generation at 132 US federal hydropower plants across the nation. This assessment leverages the latest global climate model (GCM) projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Six CMIP6 GCMs under the SSP585 emission scenario are chosen through an objective GCM selection process that factors in relative model skills, uniqueness, and data availability for downscaling. A multimodel assessment framework that includes two downscaling methods, two reference meteorological observations, two hydrologic models, and two hydropower models is used to simulate the ensemble meteorological, hydrologic, and hydropower projections in the near-term (2020-2039) and mid-term (2040-2059) future periods with respect to the historical baseline period (1980-2019). An analysis of variance approach is used to quantify the relative contribution of different modeling elements in future hydroclimatic projections. Specifically for the runoff and generation projections, while GCM represents the dominant factor, the role of hydrologic and hydropower models can be more important in some locations and seasons. Hydrologic extremes, conflicting timing of change between supply and demand, and other indirect climate change effects are also identified as potential risks that may impact the value and resilience of future federal hydropower generation.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H15B..02K