The decarbonization of the energy sector is among the leading global goals, and the electricity sector plays a crucial role in this low-carbon transition. However, South American countries have been underrepresented in this discussion. Understanding the particularities and the shifts in the electricity sector landscape of these countries over time and how natural resource availability, technology, and energy policies are decisive to a low-carbon transition summarizes the proposed matters in this research. This work aims to fill this gap by investigating past renewability trends in the electricity sector of five South American countries from 1990 to 2020 through five indicators. As a result, we observed a trend of low-carbon reverse transition in Argentina, Brazil, and Chile, despite the efforts and the success of renewable energy auctions, making short-term energy policy measures necessary. In Venezuela, there is a decrease in consumption and an increase in electricity generation using fossil fuels. Uruguay showed a rise in consumption and continued high use of renewables. Finally, energy policies focusing on quantifiable emission reduction should be a target of the electricity sector to achieve net zero emissions by 2050.

Carbon Capture, Usage and Storage (CCUS) alternatives have great relevance for the decarbonization path of the energy transition and for the international goal of net-zero emissions. The concept is related to the capture of CO₂ from stationary sources, treatment, transportation, utilization, and/or permanent storage. These low-carbon technologies can help Brazil reduce carbon emissions, mainly in the energy and industry sectors. Thus, the present chapter provides an overview of CCUS and BECCUS technologies and discusses the current scenario and future perspectives for their development in Brazil. For this, we analysed recent publications about CCUS and Bioenergy-CCUS (BECCUS) regarding the stages of capture, transport, usage and storage in Brazil, and we also systematized the technology specificities amongst CCUS and BECCUS. Some of the main results are the huge potential for associating BECCUS, considering Brazil's large production of biofuels, mainly bioethanol from sugarcane, and the advantages of capturing CO₂ from fermentation processes. The enhanced oil recovery, production of soft drinks, urea and methanol industries, and low-carbon hydrogen production are listed as some of the main possibilities for using the captured CO₂. Also, the Paraná and Santos Sedimentary Basins were considered the most prospective for carbon storage, as they are located near large-scale CO₂ emission sources and have geologic favourability. Some of the main challenges observed for projects developments in Brazil are (i) the absence of a regulatory framework; (ii) the lack of public policies and financial incentives to leverage the commercial feasibility of CCUS projects; (iii) the assessment absence of water availability without compromising its multiple uses; (iv) the absence of an integrated pipeline grid to transport CO_2; and (v) the need of a more mature characterization of sedimentary basins for CO₂ storage and long-term behaviour to guarantee safe sequestration. Keywords Energy transition, carbon capture, utilization and storage (CCUS) Decarbonization BioEnergy-CCUS (BECCUS) Brazil