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.

This study focuses on how depleted oil and gas fields can be used as geological reservoirs to support the shift towards decarbonization and sustainable, low-carbon energy systems. These reservoirs, integral to CO2 and hydrogen storage, are pivotal in harmonizing the dual objectives of environmental conservation and energy transition. We delve into the characteristics of these depleted fields, evaluating their suitability for both CO2 and hydrogen storage, each serving distinct yet complementary decarbonization roles. CO2 storage, facilitated through carbon capture and storage (CCS) technology, aims to diminish atmospheric CO2 levels, thereby mitigating climate change. In parallel, hydrogen storage in these depleted fields emerges as a strategic solution for managing the intermittency of renewable energy sources like wind and solar power. Our study starts from the premise of using depleted oil and gas fields, assessing their potential and challenges for CO2 and hydrogen storage. We define essential criteria for evaluating the feasibility of depleted reservoirs, considering the distinct nature of CO2 and hydrogen. The literature review supported the analysis developed in this research, leading to the creation of three categories of criteria — structural and tectonic, storage and containment, and impact and reactivity — which provide a comprehensive framework for evaluating the viability of these reservoirs for both gases. Through this perspective, this research aims to systematically assess how specific factors such as porosity and permeability impact the efficacy of gas storage, thereby identifying essential parameters for optimizing storage solutions for either CO2 or hydrogen.

Recent concerns about climate change and greenhouse gas emissions have a clear effect on the energy sector, directly affecting the use of fossil fuels. Companies and countries that depend on these sources of energy (so-called not clean) take actions to search for palliative solutions. The production of atlases of carbon capture and storage (CCS) is one of the collaborative actions that seeks to systematize and organize several aspects involving the use of CCS technologies. This paper focuses on an analytical overview of approaches addressed by five different CCS atlases published by Brazil, the United States, Canada, Mexico, Norway, and South Africa. The five atlases are available for public access; an analytical overview could substantiate the academic and technical decisions related to the future publication of a new atlas for any country and suggests the inclusion of new topics such as social and environmental issues.

A comunidade global estabeleceu, por meio do Acordo de Paris, a escolha de uma meta ambiciosa de redução de emissões de gases de efeito estufa durante a primeira metade do século XXI. Esse caminho requer...