• Energy Research
• 2016-2025close
• ES close
• CA close
• Polytechnic University of Milan close

Wind energy is gaining special interest worldwide due to the necessity of reducing pollutant emissions and employ renewable resources. Traditionally, horizontal axis wind turbines have been employed but certain situations require vertical axis wind turbines. With a view to improve the efficiency of a vertical axis wind turbine Savonius type, the present work proposes a bioinspired design blade profile relying on the Fibonacci spiral. This shape is repeatedly presented in nature and thus it leads to a bio-inspired blade profile. A numerical model was carried out and it was found that the Fibonacci shape improves the performance of the original Savonius shape, based on semicircular blade profiles. Particularly, the Fibonacci blade profile increases around 14% the power in comparison with the Savonius blade profile. Besides this comparison between Savonius and Fibonacci, a research study was carried out to improve the efficiency of the Fibonacci turbine. To this end, the effect of several parameters was analyzed: number of blades, aspect ratio, overlap, separation gap, and twist angle. Improvements on the average power greater than 30% were obtained.

The causal relation among building typology and building energy demand is a complex balance of climate, morphology, technology and use. The assessment of the relation between mass of building elements and energy demand in different housing typologies is the main goal of this study. A novel indicator, namely the Buildingmass, is introduced and tested in the Mediterranean climate region. Explorations on nine conventional housing typologies in Barcelona and Rome are carried out. Buildingmass evaluation is based on the calculation of the mass of building elements. Energy demand is assessed by modelling on multi-space dynamic thermal analysis tool. Our results point out that the Buildingmass has a strong relevance on energy, playing an important role in reducing heating and cooling demand in the Mediterranean city, as described by the proposed correlation (R2 = 0.88). Moreover, this indicator gives a more detailed characterisation of the housing stock of the Mediterranean city. The study aims at bridging the gap between urban physics and urban metabolism studies and fostering energy conservation measures for the built environment.

Energy Transition (ET) is crucial for sustainable development, impacting inclusive prosperity and social justice. Knowledge development, innovative solutions, and awareness actions become crucial as energy systems transform. ET necessitates behavioural and cultural changes involving individuals in responsible decision making. The active engagement of all societal actors, including people and communities is essential. The article is authored by a university research team specializing in Design for Sustainability, Service Design, and Design for Experience, and it addresses two central research questions: (i) how can individuals and communities contribute to ET? and (ii) how can design theories, methods, and expertise contribute to generating knowledge and solutions for ET? The research employs a multidisciplinary literature review and case study analysis. It is structured into two main sections. The first section examines ET, drawing upon European Union (EU) official documents and academic literature to outline its values, objectives, actors, initiatives, and challenges, focusing on the role of citizens and communities. The second section explores the design’s contributions, summarizing relevant philosophies and solutions aligned with ET goals, challenges, and bottlenecks. Conceptual maps were created to address the knowledge gap on ET objectives and guidelines, providing design-oriented reference knowledge and principles. The purpose of the research is to define a conceptual framework made up of maps to guide researchers, designers, and design educators in understanding the complexity of ET and to inspire their intervention proposals.

Abstract This paper deals with an economic aspect of distributed generation systems which rural energy cooperatives may mainly support, since they can effectively coordinate the different stakeholders within an energy access initiative. Members of a rural energy cooperative would share the costs of deploying a distributed generation system, so that each of them can benefit from it. To minimise the overall investment cost, such a cooperative must consider both technical sizing and cost allocation among its members. For the latter, an important issue to take into account is the so-called willingness-to-pay. For obtaining the design of the distributed generation system we propose to use facility location covering (FALCO) models. The solution of the FALCO model provides both the structure of the distributed generation system and the investment cost to be covered by the members of the cooperative. We take advantage of the structure of the primal and dual optimal solutions of the FALCO model to endogenously determine the minimum and maximum willingness-to-pay of the cooperative members and then to apply rationing techniques to obtain the final allocation of costs to each member. Thus, our approach optimises the generator locations and minimises the total system cost, while assigning to each member at least her minimum willingness-to-pay. From our point of view, this method may help the beneficiaries to accept the investment cost allocation. Finally, a case study based on real data from a rural village in Maharashtra, where a group of farmers wanting to buy and share an energy system to pump water for irrigating their fields, is used to illustrate the working of the proposed cost allocation methodology.

AbstractWe present a measurement of the cosmic-ray spectrum above 100 PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750 m. An inflection of the spectrum is observed, confirming the presence of the so-called second-knee feature. The spectrum is then combined with that of the 1500 m array to produce a single measurement of the flux, linking this spectral feature with the three additional breaks at the highest energies. The combined spectrum, with an energy scale set calorimetrically via fluorescence telescopes and using a single detector type, results in the most statistically and systematically precise measurement of spectral breaks yet obtained. These measurements are critical for furthering our understanding of the highest energy cosmic rays.