Arizona public power utility Salt River Project and the Electric Power Research Institute have collaborated to create a replicable approach for using hourly weather data in resource adequacy studies.
Details on the collaboration were included in a brief posted by EPRI on its website.
“Utilities are navigating increased operational and planning uncertainty amid shifting weather patterns, electrification, large customer load growth, evolving resource mixes, and rising peak temperatures. These shifts are actively altering how utilities plan, operate, and ensure reliable delivery to consumers,” the EPRI brief noted.
Resource adequacy studies depend on hourly weather data, including temperature, humidity, solar irradiance, and wind speed. “Yet, weather information for future climate conditions have historically only been available at daily resolution, lacked physical consistency across variables, or did not align with the spatial needs of utility models. Without hourly time series reflective of future weather, utilities are limited in their ability to model climate risks and assess reliability under emerging conditions,” the brief said.
SRP identified this gap as a barrier to conducting probabilistic studies examining how future climate scenarios may affect resource adequacy risk. “With extreme heat events increasing in frequency and severity, SRP planners sought a robust way to evaluate how hourly temperature, and coincident humidity, wind speed, and solar irradiance, may shift in 2035 and 2050, and how those changes could influence the overall adequacy of the system,” the EPRI brief said.
To address this challenge, SRP collaborated with EPRI to develop a forward-looking hourly weather dataset tailored to SRP’s planning needs.
To translate climate projection data into hourly inputs, EPRI applied its monthly quantile delta mapping technique, which shifts hourly historical weather profiles based on the seasonal climatological change projected by an individual or sets of climate models. "This approach preserves critical, real-world information from historical records, such as location-specific extremes, natural variability, and correlations among physically linked variables, that are otherwise missing from climate model outputs," the brief said.
Using 74 years of historical weather, EPRI generated synthetic variants corresponding to four different climate scenarios for 2035 and 2050 at load and resource locations relevant for SRP’s planning. SRP incorporated these new datasets into its existing modeling workflow, enabling it to study future system performance across a broader range of potential weather conditions, including ones that differ from historical records.
At a Climate Resilience and Adaptation (READi) workshop, EPRI and SRP presented the methodology, validation steps, and applications for system planning. The presentation focused on the scientific foundation for the dataset, the steps required to align climate projections with utility planning practices, and the practical implications for system reliability assessments.
SRP has since conducted studies to isolate the potential impacts of climate change on the adequacy of the system in future years, which has significantly improved its understanding of future climate related risks. "This collaboration demonstrates a replicable strategy for utilities to integrate forward-looking hourly weather data into existing utility planning tools to strengthen their climate informed planning capabilities," the brief said.
"Looking ahead, there are more ways utilities could leverage hourly climate datasets in their planning, including in capacity expansion modeling and climate informed load forecasting approaches. These enhanced modeling capabilities help utilities assess how shifting weather patterns may impact future power systems’ adequacy and develop resource plans that better account for climate related risks," the brief said.
“Maintaining reliability for customers is of the utmost importance to SRP as we plan for the future," said Jon Cook, Senior Principal Analyst, Resource Analysis & Planning at SRP.
"As load growth accelerates and the resource mix evolves, uncertainty in weather conditions and the future climate are becoming increasingly important considerations for resource adequacy, especially during the summer months. EPRI has been an outstanding partner in developing new data in this space, and SRP is committed to advancing innovative research to help make more informed decisions that support our customers," Cook said.
