The real assets, procedures, systems,and subsystems of a city can be virtually represented throughan urban digital twin(DT),which integrates heterogeneous data to learn and evolve with the physical city,offering support to monitor the current status and predict possible future scenarios.A DT of a city can be organized into layers, which represent specific facets of the city and cooperate to address specifici ssues.In this work,we present an application scenario in which a geometric layer,representing the 3D morphology of the urbane nvironment, cooperates with an energy consumption layer,providing knowledge of the peculiarities of thebuilding urban area and in particular of the built fabric,to assess their impact in terms of energy efficiency.The analysis of the urban geometries provides quantitative measuresas useful input,for instance,to define heat leakage.

The architectural engineering and construction sector accounts for about 30-40% of global energy consumption. The European goal of reducing this consumption and the linked greenhouse gas emissions calls for an increased capacity to implement building renovations. Building Information Modelling (BIM) and Building Performance Simulations (BPS) are among the most promising tools for fostering interdisciplinary, efficient processes and feasible analysis and design solutions to support this goal. Of the whole building stock, heritage buildings represent the most challenging part, although their potential as a driver for mitigating climate change and supporting sustainable development is being increasingly recognized. This paper presents a Heritage BIM and BPS-based workflow to support the energy and environmental improvement of publicly-owned historical buildings, that was applied to 9 case studies of 7 different Mediterranean countries. The overall aim of this research is to enhance the capacity of public local administrations and professionals to upgrade the historical building stock and demonstrate the scalability of the proposed workflow to the entire building stock of the Mediterranean area.

Meeting ever-tightening emission regulations and ambitious climate targets requires drastic efficiency improvements and emission reduction across all sectors. Hybridization as an intermediary step towards electrification is a prominent approach to achieve this. Within the forestry sector, most equipment still relies on conventional mechanical or hydraulical drivetrains. This work focuses on the design of hybrid tower yarder drivetrains, in order to facilitate the technological transition to more sustainable equipment. Tower yarder duty cycle data are extracted from the literature and organized into a set of reference duty cycle data via Matlab simulations. Based on typical performance requirements, various technological solutions are studied for the following key tower yarder subsystems: energy storage, winch drive, energy source, and energy dissipation. The objective is to determine the most performing design considering system cost, performance, weight, and durability. Challenging control considerations are discussed and control algorithms are presented. Further presented are drivetrain architecture alternatives to boost overall efficiency. The best hybrid drivetrain, based on a large set of operation data gathered from other studies, is finally subjected to design calculations and a case study involving a 5-ton tower yarder. Results indicate that off-the-shelf electric drives, reduction gearing, and energy dissipation systems can satisfy all performance requirements, including a maximum power of about 100 kW per drive. A 15-45 kWh power-dense battery pack or a 100 kWh energy-dense battery pack may be required to cope with a power of up to 70 kW RMS, pointing to a need for substantial overdesign and confirming that the energy storage system represents the largest design challenge. The engine should achieve at least 41.5 kW of power to compensate for combined average net energy consumption in the yarder. These results confirm the feasibility of tower yarder hybridization and the large potential for energy recovery. This is especially true in the closed-loop setup, with a recovered energy of up to 5 kWh per transport cycle. Finally, differences between the proposed optimal design and the commercial hybrid design by Koller Forsttechnik are discussed.

This technical guideline proposes a methodology for the energy audit of a historical building to support its energy and environmental improvement (as shown in the Energy Audit Process Flow schema based on the EN 16247-2:2014), from the analyses to the design stage up to the implementation, using Energy Performance Contracting (EPC) to attract funding. Each section of the guideline can also be used as a technical specification for tender activities. An extended version of this document is available online at the Url: https://zenodo.org/record/6393028 and includes also reference templates for drafting the reports required by each activity. 1.2 GENERAL PROJECT INFORMATION This guideline was developed within the ENI CBC Med BEEP project and aims to enhance the capacity of public local administrations to design and realise innovative energy and environmental improvement interventions on historic public buildings, through a multidisciplinary and integrated digital approach, using Building Information Modelling and performance-based design to develop an Energy Efficient Heritage Building Information Model - EE-HBIM. The guideline is based on the testing of this emerging technology on built heritage in seven different EU and non-EU Mediterranean countries, to demonstrate its scalability to the entire building stock of the Med area. The project will provide public administrations with a powerful method for the energy rehabilitation of public buildings to be supported with private funds through Energy Performance Contracting (EPC). The HBIM model should integrate previously collected information on the historical building (geometric, diagnostic, environmental data), to create a comprehensive documentation of its current state. Moreover, the model will be used as a basis to inform the subsequent simulation-based energy-environmental improvement concept, through energy renovation scenarios that are both compatible with the building and capable to enhance its energy and environmental performance.

Le azioni per il miglioramento energetico-ambientale del patrimonio co-struito sono ormai riconosciute come strategie di conservazione (Carbonara, 2015), così come gli interventi di restauro e manutenzione, in quanto volti alla trasmissione del bene alle future generazioni, perseguono obiettivi di sosteni-bilità, in una prospettiva di economia circolare. La centralità del patrimonio nelle azioni di lotta al cambiamento climatico è inoltre testimoniata dalla sua presenza nei 17 Sustainable Development Goals (Laine et al., 2019) e, in ambi-to europeo, in quanto driver fondamentale per la transizione ecologica (Potts, 2021). Il paper vuole evidenziare il contributo del progetto BEEP in questo contesto, per superare le lacune ancora esistenti nell'applicazione al patrimo-nio di strumenti avanzati di analisi e simulazione, sia attraverso esempi di suc-cesso che con attività di trasferimento competenze attraverso strumenti di LOF (Learning Outcome Framework).

The building sector accounts for a relevant portion of the overall energy consumption and CO2 emissions. The type of construction materials used in the buildings as well as the characteristics of the envelope affect their energy consumption. The choice of appropriate building materials is a crucial challenge widely discussed in the context of the bioclimatic architecture concept. The implementation of phase change materials (PCMs) into the building envelope is among the investigated solutions to make the building sector more sustainable. In this paper, cement mortar integrated with solid/solid PlusIce X25 commercial PCM was characterized and tested. The main feature of the proposed composite is the use of the solid/solid phase change, which avoids typical PCMs' issues due to the leakage occurring when the material becomes liquid. The properties of the PCM material itself were investigated by measuring the latent heat and the phase change temperature through differential scanning calorimetry (DSC). Furthermore, in order to evaluate the performance of the realized samples, an experimental setup was designed and built. The main feature of the experimental setup is the possibility to test two different cement mortar bricks subjected contemporary to the same testing conditions. Experimental results confirmed the advantages of the PCM-loaded plaster. Thermal performances of the PCM were further compared to those ones of two specimens of cement mortar incorporating rubber and cork with the same experimental conditions. Experimental results were used to validate and calibrate a finite element model, implemented in COMSOL Multiphysics 5.6. Parametric simulations to investigate the effect of the PCM mass fraction were carried out. The results showed remarkable thermal performance improvements in terms of peak temperatures reduction with mass fraction of 25-50%. Furthermore, different placements of the PCM in the wall of a building were simulated and discussed.

Battery aging is one of the major concerns for the pervasive devices such as smartphones, wearables and laptops. Current battery aging mitigation approaches only partially leverage the available options to prolong battery lifetime. In this regard, we claim that wireless crowd charging via network-wide smart charging protocols can provide a useful setting for applying battery aging mitigation. In this paper, for the first time in the state-of-the-art, we couple the two concepts and we design a fine-grained battery aging model in the context of wireless crowd charging, and two network-wide protocols to mitigate battery aging. Our approach directly challenges the related contemporary research paradigms by (i) taking into account important characteristic phenomena in the algorithmic modeling process related to fine-grained battery aging properties, (ii) deploying ubiquitous computing and network-wide protocols for battery aging mitigation, and (iii) fulfilling the user QoE expectations with respect to the enjoyment of a longer battery lifetime. Simulation-based results indicate that the proposed protocols are able to mitigate battery aging quickly in terms of nearly 46.74-60.87 % less reduction of battery capacity among the crowd, and partially outperform state-of-the-art protocols in terms of energy balance quality.

The research, carried out in collaboration between the ESTER lab of the University of Tor Vergata (network 9 of the DTC) and the BHiLab of the CNR (network 10 of the DTC) is the development of a methodology for environmental monitoring and thermographic and thermofluximetric analyses aimed at to the development of intervention scenarios to improve the energy and environmental performance of prestigious historic buildings, through an approach based on simulation. The studies were performed on Palazzo Maffei Borghese, the Italian case study of the European project ENICBCMed BEEP, coordinated by BHiLAB.

This paper proposes the design of a LLC resonant converter to supply a proton exchange membrane (PEM) electrolyzer. The PEM requires a low voltage with high current, a reduced output voltage ripple, and an overdamped dynamic behavior of the converter to avoid voltage overshoots. The designed converter allows satisfying the design constraints, minimizing switching and reverse recovery losses; the efficiency is influenced mainly by the output rectifier's conduction losses.

Energy consumption is one of the major issues in today's computer science, and an increasing number of scientific communities are interested in evaluating the tradeoff between time-to-solution and energy-to-solution. Despite, in the last two decades, computing which revolved around centralized computing infrastructures, such as supercomputing and data centers, the wide adoption of the Internet of Things (IoT) paradigm is currently inverting this trend due to the huge amount of data it generates, pushing computing power back to places where the data are generated--the so-called fog/edge computing. This shift towards a decentralized model requires an equivalent change in the software engineering paradigms, development environments, hardware tools, languages, and computation models for scientific programming because the local computational capabilities are typically limited and require a careful evaluation of power consumption. This paper aims to present how these concepts can be actually implemented in scientific software by presenting the state of the art of powerful, less power-hungry processors from one side and energy-aware tools and techniques from the other one.

The EU H2020 project MultiPACK has given the opportunity of installing three state-of-the art CO2 systems for supermarkets in South Europe, able to supply all the required thermal energy needs of the site, i.e. refrigeration, heating, cooling and hot water production. The MultiPACK units include parallel compression, ejectors for expansion work recovery and liquid recirculation and evaporator overfeeding, together with full monitoring of operation and performances. After more than one year of operations, field data of two supermarkets installed in Italy are presented and operating conditions and performance are illustrated; KPI indicators are evaluated to prepare for comparison with traditional solutions. A maximum monthly average COP of 4.2 was measured in central Italy in March 2020. The average specific energy consumption, due to Refrigeration, AC and heating, referred to the shopping area, was found to be 111 and 146 kWh myear for the two sites.

The Happen project is aimed at stimulating the market uptake of deep retrofitting of buildings, with special regard to the Mediterranean area and to the residential built stock, by tackling major bottlenecks. In the Project framework, the definition of different suitable retrofitting options for each reference building into a specific climate and "integrated sets of renovation measures" plays a pivotal role and is developed in the Work Package 3 entitled "Optimal Solutions". The present deliverable D3.5 belongs to this WP3, in particular refers to the Task 3.4, whose title is "Calculation of the holistic impact of the renovation interventions". In the present deliverable the aim is to demonstrate the holistic impact of HAPPEN, evaluating the spillover effects both for stakeholders of retrofitting and for society more in general, starting from data of the POSs fine-tuned in Task 3.3 for different countries and climate zones. In a complementary manner to T3.3, the present aim is the economic evaluation of the retrofit investment, not only from a financial point of view, but also from the environmental and social one, first through the comparison of the different solutions of retrofitting also from this point of view in order to define, for each Package of Optimal Solutions (POS) identified in the previous deliverables, the environmental and economic sustainable better solution, using combining results from Life Cycle Costing (i.e., LCC) and non-parametric technique (i.e. DDF methodology). Moreover, the positive externalities due to reduction of energy consumption and less CO2 emissions will be evaluate, also economically, thanks to the data of a survey carried out among the project partners. For each country, a single analysis will be carried out (with the construction of country files) while, for those whose where data resulted to be available, a cross-sectional analyses will be performed, to compare how the various countries behaved in terms of energy efficiency during the three periods considered. For some countries, using data and results of the DDF methodology and of the survey between the countries, a comparison will be made between before (current state of the stock of building emerging from the survey and related Primary Energy Consumption and CO2 emissions) and after deep retrofitting, in terms of possible environmental improvements and also economic savings. The main idea is to estimate costs recovery referred to CO2 and Primary Energy Consumption if the buildings of the pilot cases studies presented in deliverable D3.4 adopted the optimal solutions selected through the holistic efficiency score developed in the present deliverable. Measures on the energy efficiency of buildings, and consequently actions aimed at promoting retrofitting interventions, are very important because more and more studies are showing that, unlike what was previously thought, i.e. thermal systems for heating buildings have an impact on total CO2 emissions in urban areas, which is up to 6 times higher than the incidence of vehicular traffic.

Wireless edge networks in smart industrial environments increasingly operate using advanced sensors and autonomous machines interacting with each other and generating huge amounts of data. Those huge amounts of data are bound to make data management (e.g., for processing, storing, computing) a big challenge. Current data management approaches, relying primarily on centralized data storage, might not be able to cope with the scalability and real time requirements of Industry 4.0 environments, while distributed solutions are increasingly being explored. In this paper, we introduce the problem of distributed data access in multi-hop wireless industrial edge deployments, whereby a set of consumer nodes needs to access data stored in a set of data cache nodes, satisfying the industrial data access delay requirements and at the same time maximizing the network lifetime. We prove that the introduced problem is computationally intractable and, after formulating the objective function, we design a two-step algorithm in order to address it. We use an open testbed with real devices for conducting an experimental investigation on the performance of the algorithm. Then, we provide two online improvements, so that the data distribution can dynamically change before the first node in the network runs out of energy. We compare the performance of the methods via simulations for different numbers of network nodes and data consumers, and we show significant lifetime prolongation and increased energy efficiency when employing the method which is using only decentralized low-power wireless communication instead of the method which is using also centralized local area wireless communication.

In electrolyzers, Faraday's efficiency is a relevant parameter to assess the amount of hydrogen generated according to the input energy and energy efficiency. Faraday's efficiency expresses the faradaic losses due to the gas crossover current. The thickness of the membrane and operating conditions (i.e., temperature, gas pressure) may affect the Faraday's efficiency. The developed models in the literature are mainly focused on alkaline electrolyzers and based on the current and temperature change. However, the modeling of the effect of gas pressure on Faraday's efficiency remains a major concern. In proton exchange membrane (PEM) electrolyzers, the thickness of the used membranes is very thin, enabling decreasing ohmic losses and the membrane to operate at high pressure because of its high mechanical resistance. Nowadays, high-pressure hydrogen production is mandatory to make its storage easier and to avoid the use of an external compressor. However, when increasing the hydrogen pressure, the hydrogen crossover currents rise, particularly at low current densities. Therefore, faradaic losses due to the hydrogen crossover increase. In this article, experiments are performed on a commercial PEM electrolyzer to investigate Faraday's efficiency based on the current and hydrogen pressure change. The obtained results have allowed modeling the effects of Faraday's efficiency by a simple empirical model valid for the studied PEM electrolyzer stack. The comparison between the experiments and the model shows very good accuracy in replicating Faraday's efficiency.

The European Union 2050 climate neutrality goal and the climate crisis require coordinated efforts to reduce energy consumption in all sectors, and mainly in buildings greatly affected by the increasing temperature, with relevant CO emissions due to inefficient end-use technologies. Moreover, the old building stock of most countries requires suited policies to support renovation programs aimed at improving energy performances and optimize energy uses. A toolbox was developed in the framework of the PrioritEE project to provide policy makers and technicians with a wide set of tools to support energy efficiency in Municipal Public Buildings. The toolbox, available for free, was tested in the partners' communities, proving its effectiveness. The paper illustrates its application to the Potenza Municipality case study in which the online calculator DSTool (the core instrument of the toolbox) was utilized to select and prioritize the energy efficiency interventions in public buildings implementable in a three-year action plan in terms of costs, energy savings, CO emissions' reduction and return on investments. The results highlight that improvements in the building envelopes (walls and roofs), heating and lighting and photovoltaic systems allow reducing CO emission approximately 644 t/year and saving about 2050 MWh/year with a total three-year investment of 1,728,823 EUR.

The main objective of the article is to provide a thorough review of currently used AC-DC converters for alkaline and proton exchange membrane (PEM) electrolyzers in power grid or wind energy conversion systems. Based on the current literature, this article aims at emphasizing the advantages and drawbacks of AC-DC converters mainly based on thyristor rectifier bridges and chopper-rectifiers. The analysis is mainly focused on the current issues for these converters in terms of specific energy consumption, current ripple, reliability, efficiency, and power quality. From this analysis, it is shown that thyristors-based rectifiers are particularly fit for high-power applications but require the use of active and passive filters to enhance the power quality. By comparison, the association combination of the chopper-rectifier can avoid the use of bulky active and passive filters since it can improve power quality. However, the use of a basic chopper (i.e., buck converter) presents several disadvantages from the reliability, energy efficiency, voltage ratio, and current ripple point of view. For this reason, new emerging DC-DC converters must be employed to meet these important issues according to the availability of new power switching devices. Finally, based on the authors' experience in power conversion for PEM electrolyzers, a discussion is provided regarding the future challenges that must face power electronics for green hydrogen production based on renewable energy sources.

Video summarization (VS) has attracted intense attention recently due to its enormous applications in various computer vision domains, such as video retrieval, indexing, and browsing. Traditional VS researches mostly target at the effectiveness of the VS algorithms by introducing the high quality of features and clusters for selecting representative visual elements. Due to the increased density of vision sensors network, there is a tradeoff between the processing time of the VS methods with reasonable and representative quality of the generated summaries. It is a challenging task to generate a video summary of significant importance while fulfilling the needs of Internet of Things (IoT) surveillance networks with constrained resources. This article addresses this problem by proposing a new computationally effective solution through designing a deep CNN framework with hierarchical weighted fusion for the summarization of surveillance videos captured in IoT settings. The first stage of our framework designs discriminative rich features extracted from deep CNNs for shot segmentation. Then, we employ image memorability predicted from a fine-tuned CNN model in the framework, along with aesthetic and entropy features to maintain the interestingness and diversity of the summary. Third, a hierarchical weighted fusion mechanism is proposed to produce an aggregated score for the effective computation of the extracted features. Finally, an attention curve is constituted using the aggregated score for deciding outstanding keyframes for the final video summary. Experiments are conducted using benchmark data sets for validating the importance and effectiveness of our framework, which outperforms the other state-of-the-art schemes.

The necessity of restraining global warming to 1.5°C (IPCC Special Report 2018) implies many actions at global and local level in order to reduce CO2 emissions to net zero by 2050. Moreover, in urban area, the intensity of more and more frequent heatwaves is magnified by Urban Heat Island (UHI) effects and it increases the production of CO2 due to the intensification in cooling demand. Over the years, the historic settlement (medieval town) has showed to be more resilient to temperature changes than modern district. This paper compares the historic district with the modern one in Bari (southern Italy) in terms of morphology, type and construction technology through Envi-met simulations. It highlights how the fabric of the old town may have positive impact on summer regime for thermal comfort and its analysis can be useful for the definition of some guidelines for contemporary settlement. Natural solutions (e.g. vegetation, green roofs and water jects) and cool materials are proposed to reduce energy demand according to EU directive 2018/844 and complying with the constraints for consolidated urban area. The aim is also to evaluate the solutions for microclimate mitigation of urban canyons towards zero energy settlement starting from the old town features.

Rapporto tecnico del primo anno di attività del progetto SunHorizon

The inexorable extension of urbanization is consuming huge amounts of soil drastically reducing natural vegetation, replacing it with buildings and low albedo surfaces. The changes due to the different thermal properties of surface materials and the lack of evapotranspiration in urban areas lead to a phenomenon known as "urban heat island effect". By reintroducing the vegetation back into the urban landscape, a partnership between nature and cities should be strengthened to create a new sustainable urban environment. Since the outer surfaces of building offer a great amount of space for vegetation, planting on roofs and walls has become one of the most innovative way to provide several environmental services. Moreover, all the green infrastructures, such as urban gardens or nature areas, that form an important part of cityscapes, could ensure also a thermal isolation and constitute a sustainable energy saving solution for buildings. This work presents a critical review of environmental and potential thermal benefits of green infrastructures in the cities.