The rapid growth of wind energy has increased the need for advanced condition monitoring (CM), predictive maintenance, and remaining useful life (RUL) estimation strategies for wind turbines. In this context, digital twins (DTs) have emerged as a key tool for improving reliability, availability, and operational efficiency by integrating physical models, operational data, and artificial intelligence (AI). This paper presents a systematic literature review (SLR) aimed at analyzing the state of the art, classifying the main applications, and identifying research gaps. A rigorous search protocol was applied across scientific databases, considering inclusion and exclusion criteria and analysis categories aligned with four research questions. The results show a high concentration of studies on critical wind turbine components, a predominance of hybrid physics-based and data-driven approaches, and an increasing use of deep learning (DL) models. However, several research gaps remain, including the predominance of component-level digital twin implementations rather than system-level architectures, the lack of standardized datasets and benchmarking frameworks, and challenges related to SCADA data heterogeneity and real-time scalability. It is concluded that DTs are evolving toward more autonomous and prescriptive systems; however, they still require further maturation for widespread industrial adoption.

In response to Ecuador’s need for sustainable and locally sourced transport fuels, this study evaluates the energetic and environmental performance of a biofuel (bioethanol-based) derived from the mucilage of the CCN51 cocoa variety, analyzed under controlled operating conditions in an internal combustion engine. Bioethanol obtained from this feedstock was blended with Ecuador’s commercial Extra gasoline to produce an E5 formulation, experimentally compared with Extra (85 RON) and Super (92 RON) fuels. Physicochemical analysis following NTE INEN 2102 revealed a research octane number of 85.8 and a lower heating value of 45.22 MJ/kg. Static tests performed on a Hyundai i10 engine (2021) at 700 and 2500 rpm showed that the E5 blend achieved higher energy and exergy efficiencies (21.17% and 64.12%, respectively) than Extra gasoline, approaching Super performance. Environmentally, the E5–CCN51 blend reduced carbon monoxide (CO) by ~10–15% and unburned hydrocarbons (HC) by ~5–8%, while maintaining λ ≈ 1. Variations in O₂ and CO₂ confirmed enhanced oxidation and more complete combustion. Overall, these findings demonstrate the technical feasibility and environmental relevance of CCN51 cocoa mucilage as a sustainable ethanol source, contributing to cleaner combustion, circular bioeconomy promotion, and energy resilience in tropical developing regions.

Biomass-based energy systems represent a strategic and dispatchable renewable option for sustainable energy transitions in Latin America, where agricultural and agro-industrial residues provide significant potential for circular economy integration. This study presents a PRISMA-compliant systematic literature review synthesizing dominant biomass conversion pathways in the region, with emphasis on biofuels and bioelectricity applications and their reported technical, techno-economic, and environmental indicators. A comprehensive search of Scopus, IEEE Xplore, and ScienceDirect yielded 64 peer-reviewed studies published between 2010 and 2025. Results show a marked growth in scientific output after 2016, although evidence remains concentrated in Brazil, Colombia, and Mexico. Anaerobic digestion emerges as the most frequently assessed route, particularly for agro-industrial effluents, municipal organic waste, livestock residues, and wastewater streams, followed by combustion-based cogeneration linked to sugarcane industries. Electricity generation and biomethane dominate evaluated outputs. Overall, the review highlights technological maturity alongside persistent barriers, including fragmented supply chains, investment constraints, and limited harmonized reporting, underscoring the need for standardized frameworks and system-scale deployment across the region.

Ecuador’s energy system, heavily reliant on hydropower, is increasingly exposed to climate-related disruptions. The 2023–2024 crisis triggered by a historic drought revealed critical structural weaknesses. During this period, the government implemented scheduled electricity rationing of up to 14 h per day in major cities and industrial zones. The blackouts led to cascading economic and social impacts, with an estimated economic toll of USD 2 billion from the energy crisis, equivalent to 2% of Ecuadorian GDP. Hence, this study aims to apply the LEAP model to quantitatively simulate demand, supply, and policy outcomes under two long-term scenarios through 2050. The findings underscore the urgent need for energy diversification, efficiency improvements, and decarbonization of the transport sector to enhance system resilience. The results offer actionable insights for building a more resilient and low-carbon energy future in Ecuador and in similar hydropower-dependent economies. Additionally, the analysis highlights that institutional reforms, technological modernization, and energy integration are essential to mitigating long-term climate risks. By incorporating scenario-based projections, this study provides evidence to guide public policy and investment decisions. These findings contribute to the broader discourse on sustainable energy transitions in vulnerable economies under climate stress.

El objetivo de este estudio es el diseñar de una micro – red basada en energía limpia, tal como lo es la energía solar fotovoltaica para suministrar un área urbano marginal en específico, mediante el cual se utiliza una conexión entre las tecnologías alternativas o energías renovables y las tecnologías de los sistemas de energías convencionales. Enfatiza los conceptos, ventajas y problemáticas que se vive día a día. Mediante el proceso de la obtención y procesamiento de datos, esto se debe a que el estudio se basó en una estación meteorológica, la cual brinda datos de los diferentes parámetros como, temperatura, radiaciones, etc.; obteniendo de esta manera la temperatura histórica tanto la máxima como la mínima. Dado la posterior obtención de los datos, fueron ingresados al software PVsyst que ayudaron a la selección de los módulos fotovoltaicos y su inversor; a su vez se evaluó la factibilidad económica en lo que contempla el contexto utilizando los indicadores VAN y TIR.

Cocoa shells (variety CCN51, exclusive from Ecuador) were subjected to different thermochemical processes (combustion, pyrolysis, and gasification) to evaluate their potential for energy production. Pyrolysis was conducted at 500, 600, and 700 °C, yielding solid (35.89–41.27%), liquid (31.13–34.73%), and gas (24.92–32.92%) fractions. The higher heating value (HHV) of the solid phase increased with temperature, reaching 24.97 MJ/kg at 700 °C. Gasification was performed under air flow at 500, 600, and 700 °C, producing synthesis gas with an HHV ranging from 0.89 to 3.36 MJ/m³. The H₂ and CO contents in the gas phase increased with temperature, reaching 9.98% and 11.77% at 700 °C, respectively. Combustion analysis, conducted via thermogravimetry coupled with mass spectrometry, revealed efficient volatile release and oxidation patterns. The high potassium content in the ashes (72.02% K₂O) may affect slagging behavior but also presents opportunities for agricultural applications. These findings highlight the potential of CCN51 cocoa shells as a sustainable biomass resource, contributing to Ecuador’s green transition and the local circular economy.