In 2023 the High Contracting Parties of the Itaipu Treaty will revise the financial basis for the energy tariffs of the world’s largest renewable energy producing dam. This will awake international law issues related to sovereignty, (energy) justice, power asymmetry and social and economic rights. These issues were altogether discussed in the symposium “Annex C of the Itaipu Treaty: A discussion through the lens of sovereignty and energy justice.” The event took place on 9 July 2021. It was developed by the University of Edinburgh and counted with Ms Cecilia Llamosas from the University of Sussex as speaker, and Ana Maria Daza-Clark as chair.