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Renewable energy communities (RECs) aim at achieving economic, environmental, and social benefits for members and for society. This paper presents a roadmap for the design, operation, and monitoring of renewable energy communities in Italy, fundamental to guide and orient any stakeholder involved in the decision-making process of a REC. The roadmap is inspired by the Deming Cycle, also known as Plan-Do-Check-Act, which provides a framework for continuous improvement and standardization of the procedures. To demonstrate the practical application of the roadmap, a real case study is presented for Italian energy communities, making full adoption of data derived from official databases and using a real urban district as a case study. The findings of phase I in the “do” stage of the roadmap indicate that the REC could lead to a decrease in carbon emissions of roughly 38% and could support 51 to 67 families through REC’s revenues, depending on the installed PV capacity. Furthermore, both physical self-consumption and virtual self-consumption schemes assist in the sustainable transition of the built environment, where consumers have a significant impact on the electrical markets. Therefore, these results validate the roadmap’s effectiveness in promoting an informed design and implementation of RECs while guiding energy, social, and political decisions.

This study aims to propose the repowering of an existing Italian natural-gas fired combined cycle power plant through the integration of Molten Carbonate Fuel Cells (MCFC) downstream of the gas turbine for CO2 capture and to pursuit an exergetic analysis of the two schemes. The flue gases of the turbine are used to feed the cathode of the MCFC, where CO2 is captured and transported to the anode while generating electric power. The retrofitted plant produces 787.454 MW, in particular, 435.29 MW from the gas turbine, 248.9 MW from the steam cycle, and 135.283 MW from the MCFC. Around 42.4% of the exergy destruction has been obtained, the majority belonging to the combustion chamber and, in minor percentages, to the gas turbine and the MCFC. The overall net plant efficiency and net exergy efficiency are estimated to be around 55.34 and 53.34%, respectively. Finally, the specific CO2 emission is around 66.67 kg/MWh, with around 2 million tons of carbon dioxide sequestrated.

In response to the Positive Energy District transition, this paper proposes an energy tool for the modeling of energy sharing configurations among buildings equipped with energy production systems and distributive storages. The model is targeted for urban planners and energy policymakers and gives insights into the role of buildings in fostering the achievement of net-zero energy balances in districts when virtual or physical peer-to-peer configurations are established in the area. A real urban district is considered as a case study and the energy performances are measured against properly defined Key Performance Indicators. Results confirm the strategic role played by energy sharing among buildings in achieving self-sufficient and carbon-neutral areas. In particular, the insertion of storages allows not only for higher self-sufficiency of the area (by facilitating the coupling of production and demand) but also for higher distribution rates among buildings. However, photovoltaic insertion and storages should be appropriately balanced since it has been observed that at increasing the number of production and storage systems, the distribution is reduced in favor of autonomy, thus limiting the usefulness of an interconnected local distribution grid.

Complexity is a widely acknowledged feature of urban areas. Among the different levels to which this definition applies, the energy sector is one of the most representative of this way of conceiving cities. An evidence of this complexity can be detected in the growing impact of prosumers. Prosumers produce energy to meet their own demands, distribute it directly to neighbors and, eventually, store the energy neither consumed nor distributed. The modelling of distribution networks is a challenging task that requires ad hoc models to simulate the mutual energy exchanges occurring among prosumers. To serve at this scope, this paper proposes an agent-based model aiming at determining which operating conditions enhance the energy distribution among prosumers and diminish the supply from traditional power plants. An application of the model within a residential territory is then presented and simulations are conducted under two scenarios: the first investigating the distribution among prosumers equipped with photovoltaics (PV) systems, the second integrating energy storage systems to PV panels. Both scenarios are studied at varying the installed PV capacity within the territory, the allowed distance of connection among prosumers, as well as the rate of utilization of the links of the network. Results from the simulated case study reveal that the energy distribution among prosumers can be enhanced by providing short-range links for the electricity exchange. Similar advantages can be achieved by integrating storage systems to PV, along with a significant reduction in the electricity requested to the centralized grid.

The power sector is undergoing a fundamental transition from centralized fossil-fuelled to distributed production systems. Usually, the decentralization of the energy distribution is treated by considering the interactions between prosumers and main grid, neglecting to include the rising chance for prosumers to directly exchange the produced energy, thus bypassing the grid. In this direction, this paper proposes a prosumer-centred dynamical model able to take the energy interactions among prosumers into account, along with the usual interactions established with the grid. The modelling approach takes inspiration from the methodological framework of agent-based models, particularly appropriate to deal with problems characterized by a significant number of interactions among the parts. Specifically, the developed model has been formulated with the main scope of investigating to what extent energy exchanges among prosumers reduce the supply from traditional plants. The electricity demand and production of each prosumer, the distance among buildings, operational and technological features (usage of the links, installed capacity of the energy production systems have been included in the analysis. Hourly-based simulations run on NetLogo performing a real urban area in Southern Italy as a case study for two scenarios evaluating the distribution from photovoltaic panels and small-scale cogeneration units. In addition, an a posteriori environmental analysis to evaluate the reduction of carbon emissions due to the distribution among prosumers has been conducted. Results reveal that short-range interactions among prosumers are preferred when planning to reduce the electricity supply from the main grid. In addition, the spatial configuration of the buildings within the area as well as the capacity of the installed energy production systems significantly affect the distribution. Finally, simulations highlight the noticeable impact of seasonality on both the distribution and the emissions’ reduction.

Combined heat and power systems are widely recognized as a cost-effective solution for the achievement of sustainable and energy efficiency goals. During the last decade, cogeneration systems have been extensively studied from both the technological and operational viewpoints. However, the operation of a cogeneration system is a topic still worth of investigation. In fact, along with the determination of the optimal configurations of the combined heat and power systems, it is likewise fundamental to increase the awareness on the design and cost parameters affecting the operation of cogeneration systems, especially if considering the micro-grid in which they are inserted. In this direction, this paper proposed a mixed integer linear programming model with the objective of minimizing the total operational costs of the micro-grid. Different scenarios include the satisfaction of the cooling demands of the micro-grid as well as the opportuneness to include a heat storage. The influence of the main design and cost parameters on the operation of the micro-grid has been assessed by adopting the statistical tool ANOVA (Analysis Of Variance). The model and the experimental application of the ANOVA have been applied to a micro-grid serving a hospital located in the South of Italy.

Energy demand and production of neighbourhoods are central issues in the development of integrated spatial-energy strategies in the framework of recent European Policies. This study provides a comprehensive tool that combines spatial and energy issues with optimization methods to support urban planners in the decision-making process for urban energy strategies. By adopting an integrated approach, optimized urban energy scenarios aimed at reducing CO2 emissions are developed and results are shown in spatial-energy maps. Through the application of the proposed method, current urban energy demand is determined and potential local production of electrical energy due to the introduction of renewable energy systems is assessed. The insertion of renewable energy systems allows configuring a network of energy exchanges where buildings are considered able to share energy through physical connections. The optimization of energy exchanges among buildings is carried out by using a model based on complex networks and is represented in maps, developed in GIS, allowing the integration between energy evaluations and spatial planning. As case study, the method has been applied to a neighbourhood of the municipality of Catania in Southern Italy.

According to the Fifth Assessment Report of the International Panel on Climate Change, cities account for the 67% of the global energy demand and are the major contributors in emitting CO2 in the atmosphere. To face this problem, National and European policies pushes towards the insertion of distributed energy systems within urban areas as a valid alternative to the traditional centralized energy supply. In this direction, the installation of distributed energy systems gives raise to consumers with production capabilities, by now called ‘prosumers’. They use the autonomously produced energy to satisfy their own energy requirements and distribute the eventual exceed to neighbours. Yet, the energy exchanges occurring among prosumers permit the modelling of a network where nodes are identified as the prosumers and the energy interactions as links. This paper deals with this issue and proposes a cost-based methodology to model the energy distribution network of prosumers within the urban territories by deepening their impact on the traditional supply. Results are discussed by comparing a theoretical energy distribution network to a real case study.

The International Standards ISO 50001 and ISO 50006 can be easily transferred to organizations, which outputs consist of tangible products. However, it is equally important to build an energy management system tailored to public organizations, whose outputs are often immaterial goods and in which buildings highly affect the overall energy performances. Commonly, energy performances of buildings are assessed by comparison with sector-based benchmarks, whilst monitoring and control practises are often overlooked. Under these premises, this paper aims at proposing a common framework for an energy management system tailored to public organizations in which buildings play a pivotal role in targeting energy performance improvement. The proposed energy management system also relies on the effective exploitation of monitoring and control tools to promptly identify deviations from the expected energy performance values and to evaluate improvements over time.

This paper explores the viability of Carbon Capture and Storage (CCS) in Italy by examining two different scenarios. The first scenario evaluates the investments on traditional power generation technologies, i.e. USC (Ultra Super Critical), NGCC (Natural Gas Combined Cycle) and IGCC (Integrated Gas Combined Cycle), with and without CCS, and on wind farms; the second scenario studies the convenience of retrofitting existing Italian power plants with respect to the construction of new capture-ready plants. To the scope, a techno-economic analysis based on the calculation of the LCOE (Levelised Cost Of Electricity), the CCAV (cost of CO2 avoided) and the CCAP (cost of CO2 captured) is assessed. Beyond these measures, the analysis in both scenarios accounts for the calculation of the so-called LACE (Levelised Avoided Cost of Electricity) in order to evaluate the profitability of CCS systems and, therefore, to properly orient CCS investment decision in Italy.

Significant research contributions and Directives approach the issue of the insertion of renewable-based energy systems on urban territory in order to face with the growing energy needs of citizens. The introduction of such systems gives raise to installers to both satisfy their energy demands and distribute eventual energy excesses to close neighbours. This paper presents a multi-layer agent-based computational model that simulates multiple event of the network of the energy distribution occurring within urban areas. The model runs on the NetLogo platform and aims at elaborating the most suitable strategy when dealing with the design of a network of energy distribution. Experimental data are discussed on the basis of two main scenarios within an operating period of 24 hours. Scenarios consider both the variation of the percentages of installers of renewable-based energy systems and the distance along which energy exchanges occur., 22 pages, 15 figures

Since cities are responsible for 67% of the world’s energy demand and are the major contributors of CO 2 emissions, governments and researchers push towards energy policy initiatives aiming at increasing the sustainability of urban areas. In this context, the diffusion of autonomous energy production systems on territory has been recognized as a cost-effective solution. The integration of distributed energy systems in cities gives to consumers the possibility to exchange their own produced energy. In order to design the optimal energy distribution network among consumers and, at the same time, minimize the energy supply from traditional power plants, a comprehensive and focused approach is introduced and developed in this paper. The presented model encompasses the frameworks of complex networks theory and energy distribution issues, thus providing a suitable solution than current models. A real case study is then presented to validate the numerical results. Overall, the proposed model offers significant insights for the definition of proper urban action plans centered on the efficient usage of energy and favoring the exploitation of renewable energy, thus allowing urban planners to make reasoned investment decisions.

Organized by 36th UIT Heat Transfer Conference Catania, 25-27 June, 2018 The annual UIT Heat Transfer Conference of the “Unione Italiana di Termofluidodinamica” (UIT) aims at endorsing the collaboration among scientists and engineers working in the field of heat transfer and thermal sciences. The 36th UIT Conference was held in Catania, Italy, 25-27 June, 2018 at the Four Points by Sheraton Hotel. The coverage of topics reflects the current interests of the international and Italian research communities, such as natural, forced and mixed convection, conduction, radiation, computational fluid dynamics, multi-phase fluid dynamics and interface phenomena, heat transfer in nuclear plants, flow visualization, heat transfer and efficiency in energy system, environmental technologies and buildings. With 72 abstracts, 36 oral and 22 poster contributions, the Conference provided not only the opportunity for authors to present and discuss their research development, but also to stimulate the debate on their respective research areas. Keynote Lectures were given by Professor Giovanni S. Barozzi (University of Modena and Reggio Emilia), Professor Michele Ciofalo (University of Palermo) and Professor Marco Marengo (University of Brighton). These Proceedings contain 50 full papers, selected from among the scientific contributions discussed during the Conference. The Editors thank the authors for their participation and contributions, the Scientific Committee and the reviewers for their efforts. Special thanks are extended to the Organizing Committee. The Editors gratefully acknowledge the Italian Union of Thermal-Fluid Dynamics (UIT) and its President, Professor Alfonso Niro, for all efforts made for promoting the Conference. Finally, they acknowledge the financial support of the University of Catania. Alberto Fichera, Arturo Pagano and Rosaria Volpe - Editors Scientific Committee of the 36th UIT Heat Transfer Conference Alberto Fichera, Chair Università degli Studi di Catania, Italy Paolo Baggio Università degli Studi di Trento, Italy Giovanni S. Barozzi Università degli Studi di Modena e Reggio Emilia, Italy Gian Paolo Beretta Università degli Studi di Brescia, Italy Neima Brauner Tel Aviv University, Israel Gianni Cesini Politecnica delle Marche, Italy Gian Piero Celata Centro Ricerche ENEA Casaccia, Rome, Italy Wilson K.S. Chiu University of Connecticut, USA Michele Ciofalo Università degli Studi di Palermo, Italy Luigi P.M. Colombo Politecnico di Milano, Italy Davide Del Col Università degli Studi di Padova, Italy Paolo Di Marco University of Pisa, Italy Walter Grassi University of Pisa, Italy Adriano Lezzi Università degli Studi di Brescia, Italy Giovanni Longo Università degli Studi di Padova, Italy Oronzio Manca Seconda Università degli Studi di Napoli, Italy Luigi Marletta Università degli Studi di Catania, Italy Rita Mastrullo Università degli Studi di Napoli Federico II, Italy Gianluca Morini Università degli Studi di Bologna, Italy Vincenzo Naso Università degli Studi di Napoli Federico II, Italy Hisashi Ninokata Professor Emeritus of the Tokyo Institute of Technology, Japan Alfonso Niro Politecnico di Milano, Italy Enrico Nobile Università degli Studi di Trieste, Italy Carlo Nonino Università degli Studi di Udine, Italy Bruno Panella Politecnico di Torino, Italy Sara Rainieri Università degli Studi di Parma, Italy Gianfranco Rizzo Università degli Studi di Palermo, Italy Luisa Rossetto Università degli Studi di Padova, Italy Peter C. Stephan Technische Universität Darmstadt, Germany Giovanni Tanda Università degli Studi di Genva, Italy John R. Thome École Polytechnique Fédérale de Lausanne (EPFL), Switzerland Akio Tomiyana Kobe University, Japan Organizing Committee Alberto Fichera, chair Gianpiero Evola Antonio Gagliano Luigi Marletta Francesco Nocera Arturo Pagano Rosaria Volpe

Cities are responsible for the 70% of the world's energy demand and represent the largest source of GHG emissions. The constant growth of cities encourages towards the configuration of urban energy plans in order to make urban areas more sustainable places. In this direction, Decentralized Energy Systems (DES) play an important role in order to improve the efficiency in urban energy consumptions. However, the decentralization of urban energy systems requires a comprehensive evaluation of the energy interactions that can occur among consumers. To this aim, proper mathematical models need to be defined in order to take into account how those interactions occur. In this paper, a mathematical procedure based on the complex network theory is introduced and tested to a neighborhood within the city of Catania.

The concept of Positive Energy District is one of the main areas of research and extensive applications of the principles of the clean energy transition within the building sector. In the past years, the most widely accepted definitions have focused specifically on carbon neutrality, while several other aspects regarding all sustainability approaches (including environmental, social and economic perspective) were included qualitatively or to a lesser degree. This paper proposes a discussion on the state of the art of the sustainability assessment of Positive Energy Districts, by investigating environmental, social and economic sustainability applications. The three sustainability dimensions are investigated individually first, while discussing methodological insights, key performance indicators used and quantitative results, as well as in an integrated perspective. Finally, the paper describes research gaps and areas for further development on the topic.