The California Energy Commission (CEC) presents this Winter 2024–2025 California Gas Reliability Assessment (Winter Assessment) to assess the risk of curtailment of Pacific Gas and Electric (PG&E) and Southern California Gas (SoCalGas)/San Diego Gas and Electric (SDG&E) gas service to gas-fired power plants and other noncore customers such as factories and large commercial facilities. The risk of curtailment of gas service to core customers (generally residential and small commercial customers) is lower as reliability standards for them have been designed to ensure that even under the most extreme cold conditions, gas service is maintained without interruption. Staff developed monthly demand and peak day demand forecasts for Winter 2024-25 and incorporated them into gas balance models, stochastic models, gas system simulations in the form of hydraulic models to assess how the PG&E and SoCalGas will meet demand in average months, cold months, and under two peak day scenarios.
The CEC staff analysis in this report finds that on extremely cold winter days, the PG&E gas system cannot meet demand without withdrawals from underground gas storage facilities owned by Independent Storage Providers (ISPs), that are generally transactions between gas marketers representing power plants and other large customers and the storage facility. Other measures can be deployed to address the shortfall including PG&E procuring gas from the ISPs and issuing an Operational Flow Orders (OFO) during system imbalances.
CEC staff estimates that SoCalGas can meet extremely cold day demands without curtailment of noncore customers due to having enough pipeline supply and storage withdrawal capacity. However, there are risks for both gas utility systems, including the potential impacts of scheduled and unscheduled maintenance events on key mainlines and storage facilities.
