Impacts of potential investments on electricity resource adequacy and emissions in Texas

Growing demand, an increasingly variable power supply, and blackouts during a 2021 winter storm prompted the Texas legislature to incentivize the construction of dispatchable energy resources in the Electric Reliability Council of Texas (ERCOT) region. However, the absence of a comprehensive assessment of how different investment options affect both resource adequacy and emissions had left a gap in predicting the outcomes of the legislation. Here, two power system models were used to evaluate how potential investments in dispatchable generation, battery storage, transmission, or energy efficiency would affect resource adequacy and emissions in ERCOT. The Regional Energy Deployment System (ReEDS) model was used to project system capacity expansion under each scenario. Its outputs for the year 2030 were provided to the Python for Power System Analysis for the United States (PyPSA-USA) model to estimate hourly resource adequacy under historical weather conditions.Model results indicate that adding dispatchable capacity and long-duration batteries would lead to more rapid closure of coal plants in ERCOT while slowing the growth of wind and solar only slightly, thus reducing greenhouse gas and air pollutant emissions and averting up to 100 premature deaths annually. Building transmission lines across regions would primarily accelerate the deployment of wind farms. Adding dispatchable capacity and improving energy efficiency would enhance resource adequacy during both winter and summer extreme weather events, while batteries are particularly effective during heat waves.