  The United States has witnessed a growing prevalence of droughts in recent
years, posing significant challenges to water supplies and power generation.
The resulting impacts on power systems, including reduced capacity and the
potential for power outages, underscore the need for accurate assessment
methods to ensure the reliable operation of the nation's energy infrastructure.
A critical step is to evaluate the usable capacity of a regional power system's
generation fleet, which is a complex undertaking and requires precise modeling
of the effects of hydrological and meteorological conditions on diverse
generating technologies. This paper proposes a systematic, analytical approach
for assessing the impacts of extreme summer drought events on the available
capacity of hydro, thermal, and renewable energy generators. More specifically,
the systematic framework provides plant-level capacity derating models for
hydroelectric, once-through cooling thermoelectric, recirculating cooling
thermoelectric, combustion turbine, solar PV, and wind turbine systems.
Application of the proposed impact assessment framework to the 2025 generation
fleet of the real-world power system in the PJM and SERC regions yields
insightful results. By examining the daily usable capacity of 6,055 at-risk
generators throughout the study region, we find that in the event of the
recurrence of the 2007 southeastern summer drought in the near future, the
usable capacity of all at-risk power plants may experience a substantial
decrease compared to a typical summer, falling within the range of 71% to 81%.
The sensitivity analysis reveals that the usable capacity would experience a
more pronounced decline under more severe drought conditions. The findings of
this study offer valuable insights, enabling stakeholders to enhance the
resilience of power systems against the potential effects of extreme drought in
the future.
