The transition towards low-carbon energy systems has been increasingly recognised as a critical global priority for mitigating climate change, reducing dependence on fossil resources, and promoting sustainable socioeconomic development. Although Brazil possesses one of the world’s most renewable energy matrices, supported primarily by hydropower, bioenergy, wind, and solar resources, significant challenges remain in the effective integration of waste-to-energy technologies and circular resource management strategies. In this review, the current status of renewable energy deployment in Brazil is critically assessed alongside the generation, management, and valorisation potential of major waste streams, including agricultural biomass, agro-industrial residues, food-processing wastes, municipal solid waste (MSW), wastewater sludge, construction and demolition waste (CDW), pulp and paper residues, and end-of-life tyres. Existing treatment practices and recovery technologies are systematically examined with emphasis on their capacity to convert waste into value-added products such as solid, liquid, and gaseous biofuels, secondary raw materials, and platform chemicals. Particular attention is given to technological limitations, regional disparities in infrastructure, and policy gaps that have constrained the broader implementation of decentralised renewable energy systems, especially in rural and residential sectors. It is observed that despite substantial progress in renewable electricity generation, waste recycling rates, energy recovery efficiency, and integrated waste management practices remain comparatively underdeveloped. The adoption of advanced thermochemical, biochemical, and material recovery technologies is shown to offer significant opportunities for emissions reduction, resource efficiency, and industrial symbiosis. Furthermore, the role of regulatory frameworks, economic incentives, and public investment in accelerating the transition towards a circular and low-carbon economy is highlighted. The findings demonstrate that the strategic integration of renewable energy expansion with waste valorisation could substantially enhance energy security, environmental performance, and economic resilience in Brazil. The technological pathways, policy mechanisms, and management strategies discussed are also considered transferable to other emerging economies facing similar energy and waste management challenges.

Port cities and their hinterlands present particular challenges for sustainable development, including high energy demand, urban heat island (UHI) effects, energy poverty, and environmental impacts from port operations. This work aims at verifying two hypotheses: first, that increasing renewable energy community (REC)/self-consumption scheme (SCS) membership significantly improves self-consumption performance for a fixed photovoltaic (PV) installation; and second, that the spatial distribution of impervious surfaces in port hinterland areas is directly correlated with UHI intensity and therefore highlights priority zones for Nature-based Solution (NbS) intervention. An hourly photovoltaic simulation model is used to evaluate the effect of community size on the self-consumption factor, and a geographic information system analysis combining Copernicus reanalysis temperature data and high-resolution land cover layers is used to characterize UHI dynamics in Genoa. The implementation framework is provided by the EnerCmed project, which is co-funded by the European Union (EU)’s Interreg Euro-MED programme. The simulation results demonstrate that with an increase in REC/SCS membership from 1 to 30 apartments, the self-consumption factor increases from 5% to 50% for a 50 kWp installation. The results of the UHI analysis show nocturnal summer intensification of +3 to +4 °C in the Genoa port hinterland area, with strong correlation with impervious surface density. The results show how renewable energy governance coupled with nature-based climate adaptation strategies can simultaneously improve renewable energy self-consumption and mitigate urban heat stress in port cities’ hinterlands. These findings support the new hybrid approach as an effective replicability strategy for green harbors and sustainable Mediterranean port cities.

Renewable energy communities (RECs) are central to the European energy transition because they can turn passive consumers into active prosumers and support more decentralized, community-based energy systems. This perspective paper examines the evolution of RECs in Italy, asking whether their current development trajectory can move beyond incentive-dependent deployment toward more resilient and market-integrated models. Italy offers a particularly relevant case because it combines advanced regulatory transposition and rapid diffusion with persistent structural weaknesses. The analysis draws on regulatory documents, diffusion data, economic and governance evidence, market and grid data, and recent audit evidence from the European Court of Auditors. We trace the development of RECs from the European Union (EU)’s Clean Energy Package through Italy’s Legislative Decree 199/2021 and Autorità di Regolazione per Energia Reti e Ambiente (ARERA)’s Testo Integrato Autoconsumo Diffuso (TIAD) framework, and the emerging Testo Integrato del Dispacciamento Elettrico (TIDE) pathway for market integration. The paper argues that REC diffusion in Italy is constrained by an “incentive trap”: although RECs are designed to promote local empowerment, they remain structurally dependent on national support schemes and are still weakly connected to wholesale markets, ancillary services, and grid flexibility mechanisms. We identify three strategic pillars for overcoming this limitation: governance innovation that combines economic viability, social equity, and digital solutions; regulatory pathways that enable aggregation, demand response, balancing-market participation, local flexibility, and storage; and diversified revenue streams based on local energy trading, demand response, multi-service provision, and grid-support services. The paper contributes to debates on energy democracy and decentralized energy systems by proposing an evolutionary framework through which Italian RECs can preserve their social value while becoming adaptive market actors.