Integrated Long-Term Expansion Planning and Short-Term Operation Assessment for Decarbonisation Pathways in Brazil Considering Utility-Scale Storage

Long-term power system expansion planning (LTEP) aligned with decarbonization policies is crucial for achieving net zero emissions, especially in developing countries. This paper presents a comprehensive model for LTEP in Brazil, considering decarbonization pathways. The model combines OSeMOSYS with Flextool for short-term operation (STO) assessment. A notable contribution is the utility-scale storage model included in OSeMOSYS, enabling system flexibility and reliability evaluation. Four policy scenarios simulate different investment approaches in renewable energy sources and storage. Results show that increasing variable renewable energy (VRE) to 40% of total capacity, with or without storage, has a less than 2% cost difference compared to the business-as-usual scenario. The total cost of an increased VRE scenario with battery storage is lower than the same scenario without batteries, highlighting storage's economic benefits. Integrated LTEP and STO evaluation provides valuable insights for decision-makers, emphasizing the importance of both in decarbonization strategies.