This paper presents a comprehensive overview on the current status of solid oxide fuel cell (SOFC) energy systems technology with a deep insight into the techno-energy performance. In recent years, SOFCs have received growing attention in the scientific landscape of high efficiency energy technologies. They are fuel flexible, highly efficient, and environmentally sustainable. The high working temperature makes it possible to work in cogeneration, and drive downstream bottomed cycles such as Brayton and Hirn/Rankine ones, thus configuring the hybrid system of a SOFC/turbine with very high electric efficiency. Fuel flexibility makes SOFCs independent from pure hydrogen feeding, since hydrocarbons can be fed directly to the SOFC and then converted to a hydrogen rich stream by the internal thermochemical processes. SOFC is also able to convert carbon monoxide electrochemically, thus contributing to energy production together with hydrogen. SOFCs are much considered for being supplied with biofuels, especially biogas and syngas, so that biomass gasifiers/SOFC integrated systems contribute to the “waste to energy” chain with a significant reduction in pollution. The paper also deals with the analysis of techno-energy performance by means of ad hoc developed numerical modeling, in relation to the main operating parameters. Ample prominence is given to the aspect of fueling, emphasizing fuel processing with a deep discussion on the impurities and undesired phenomena that SOFCs suffer. Constituent materials, geometry, and design methods for the balance of plant were studied. A wide analysis was dedicated to the hybrid system of the SOFC/turbine and to the integrated system of the biomass gasifier/SOFC. Finally, an overview of SOFC system manufacturing companies on SOFC research and development worldwide and on the European roadmap was made to reflect the interest in this technology, which is an important signal of how communities are sensitive toward clean, low carbon, and efficient technologies, and therefore to provide a decisive and firm impulse to the now outlined energy transition.

Transportation is one of the largest sources of CO₂ emissions, accounting for more than 20% of worldwide emissions. However, it is one of the areas where decarbonization presents the greatest hurdles, owing to its capillarity and the benefits that are associated with the use of fossil fuels in terms of energy density, storage, and transportation. In order to accomplish comprehensive decarbonization in the transport sector, it will be required to encourage a genuine transition to low-carbon fuels and the widespread deployment of the necessary infrastructures to allow for a large-scale innovation. Renewable hydrogen shows potential for sustainable transportation applications, whether in fuel cell electric vehicles (FCEVs), such as automobiles, trucks, and trains, or as a raw material for ship and airplane synthetic fuels. The present paper aims to present how hydrogen-fuel cell hybrid powertrains for road vehicles work in terms of conceptual layouts and operating strategies. A comprehensive overview of real and current applications is presented, concerning existing prototypes and commercially available vehicles, with a focus on the main key performance indicators, such as efficiency, mileage, and energy consumption.

This study delves into the adoption of the organic Rankine cycle (ORC) for recovering waste heat from data centers (DCs). Through a literature review, it examines energy reuse with a focus on electric power generation, the selection of working fluids, and system design principles. The objective is to develop a thorough framework for system design and analysis, beginning with a quantity and quality investigation of waste heat available. Air cooling systems, chosen often for their simplicity, account for about 70% of used cooling methods. Water cooling demonstrates greater effectiveness, albeit less commonly adopted. This study pays close attention to the selection of potential working fluids, meticulously considering the limitations presented by the available sources of heat and cold for vaporization and condensation, respectively. It reviews an ORC-based system setup, incorporating fluid streams for internal processes. The research includes a conceptual case study where the system is designed and simulations are conducted in the DWSIM environment. The simulation model considers hot air or hot liquid water returning from the data center cooling system for ORC working fluid evaporation. Ambient water serves for condensing, with pentane and isopentane identified as suitable organic fluids. Pentane assures ORC net electric efficiencies ranging between 3.1 and 7.1% when operating pressure ratios increase from 2.8 to 6.4. Isopentane systems, meanwhile, achieve efficiencies of 3.6–7.0% across pressure ratios of 2.7–6.0. Furthermore, the investigation provides key performance indicators for a reference data center in terms of power usage effectiveness (PUE), energy reuse factor (ERF), energy reuse effectiveness (ERE), and greenhouse gas (GHG) savings. This study concludes with guidelines for system analysis, including exergy considerations, and details the sizing process for evaporators and condensers.

This review paper examines the critical intersection of energy consumption and environmental impacts within the global food system, emphasizing the substantial footprint (including land usage, costs, food loss and waste, and carbon and water footprints) associated with current practices. The study delineates the high energy demands and ecological burdens of food production, trade, and consumption through a comprehensive bibliographic analysis of high-impact research papers, authoritative reports, and databases. The paper systematically analyzes and synthesizes data to characterize the food industry’s current energy use patterns and environmental impacts. The results underscore a pressing need for strategic interventions to enhance food system efficiency and reduce the footprint. In light of the projected population growth and increasing food demand, the study advocates for a paradigm shift towards more sustainable and resilient food production practices, adopting energy-efficient technologies, promoting sustainable dietary habits, and strengthening global cooperation among stakeholders to achieve the Sustainable Development Goals. Investigations have revealed that the food system is highly energy-intensive, accounting for approximately 30% of total energy consumption (200 EJ per year). The sector remains heavily reliant on fossil fuels. Associated greenhouse gas (GHG) emissions, which constitute 26% of all anthropogenic emissions, have shown a linear growth trend, reaching 16.6 Gt_CO2eq in 2015 and projected to approach 18.6 Gt_CO2eq in the coming years. Notably, 6% of these emissions result from food never consumed. While the water footprint has slightly decreased recently, its demand is expected to increase by 20% to 30%, potentially reaching between 5500 and 6000 km³ annually by 2050. Energy efficiency interventions are estimated to save up to 20%, with a favorable payback period, as evidenced by several practical implementations.