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Green roofs are widely used in hot or cold climates mainly because they are capable to improve the energy efficiency of buildings and, when implemented at a large scale, reducing air pollution and the urban heat island effect (UHI) in urban contexts. Artificial Neural Network (ANN) black-box algorithms are a valid alternative to studying complex systems. However, the literature highlights - quite surprisingly – none of the available research refers to coupling ANNs and green roofs in the Mediterranean area, where green roofs are instead considered one of the most suitable technologies to reduce the high cooling demand. Therefore, the objective of this research work is to create and validate an ANN for the prediction of the monthly green roof’s internal and external surface temperatures and the monthly internal air temperature, starting from different green roof parameters and climatic variables. Specifically, the ANN was created with reference to a Mediterranean climate considering an existing green roof on a building of the University of Palermo characterized by a cooling demand predominance; 180 green roof configurations, obtained by varying the characteristic parameters of vegetation (plant height, leaf area index and leaf reflectivity) and the substrate thickness and thermophysical properties (lightweight and heavyweight), were dynamically simulated on an hourly basis to build the training dataset. In addition, other 72 green roof configurations were simulated to generate the dataset for the validation purpose of the ANN accuracy. The optimal ANN-related architecture consists of 90 neurons with one hidden layer and guarantees very high accuracy predictions. The outcomes of this research represent a useful tool to determine the thermal response of green roofs and their impact on the building energy demand and indoor thermal comfort and UHI mitigation.

European directives promote activities aimed at developing a sustainable and decarbonised energy system, with a greater share of electricity production from renewable sources, within a framework of greater efficiency. In the energy of nZEB buildings, the reduction of energy needs is accompanied by the use of hybrid renewable energy systems (HRES) for the production of energy on-site to be used for appliances and lighting and also for mobility through the electric vehicle (EV) charging. With reference to this framework, the paper studied the integration of Vehicle to Home (V2H) technology in HRES for residential users. The HRES consists of a photovoltaic (PV) generator, a wind generator, an electrical storage system and a charging station for an EV, in a stand-alone context. V2H technology provides for the use of the EV as an emergency energy source if the generation and storage systems are unable to guarantee the satisfaction of the residential load. For this purpose, an algorithm is proposed that can manage and optimize the dissipated energy produced in excess, providing that this is sent, when possible, to the EV for extra charging compared to the residential charging expected in the load determination. This extra charging process does not affect the load required by the residential user being carried out directly by the generation system with the excess energy produced. With reference to an isolated single-family user not connected to the network and to the use of an EV (which ensures mobility), two energy scenarios were considered, in the absence and the presence of V2H technology. The possibility of EV charging at night and an additional extra charge during the day were considered. The load required for nocturnal EV charging rests on the residential load of the home, while the extra charge is directly borne by the generation system. To reduce excess energy, which in the considered context must be dissipated, two charging strategies were considered that differ in the choice of whether or not to carry out nocturnal charging depending on the EV state of charge. The different system configurations and use of the generated energy make the energy analysis complete to identify the performance of these systems. The dynamic simulations of the HRES operation were carried out through TRNSYS, for the dynamic simulation of the PV and wind systems, which is coupled with MATLAB to dynamically simulate the residential battery and the H2V and V2H technologies. Starting from the hourly results obtained, an yearly energy analysis was carried out.

The rapid and widespread deployment of green roofs requires the need to address their disposal and to assess the environmental impact of this phase of their life cycle to understand whether their current large-scale application may pose a problem. A review of the literature on green roofs environmental performance (particularly Life Cycle Assessment studies) has highlighted the lack of a standardized, commonly adopted, procedure for determining the treatments, recovery and/or disposal, to be assigned to waste from the removal of green roofs. In this regard, it should be mentioned that there is a lack of ad hoc legislation on the disposal of this technology (to the best of the authors’ knowledge, even at the international level). In this paper, an attempt procedure is introduced to identify the end-of-life scenario of green roofs that does not conflict with the current regulations regarding wastes. Specifically, the procedure relies on an “attempt classification” of the waste from individual green roof elements and the priority criterion for intervention. This procedure might thus be used temporarily by technicians, pending the issuance of guidelines specifically dedicated to green roofs disposal, to model their end-of-life and thus assess the environmental impact of this phase of the life cycle. The feasibility of this proposal was verified through a field application. Besides the methodological proposal, the results of the work indicated the need to review the current waste legislation and update it -at least the Italian one - to also consider new materials used in green transition technologies.

In recent years, research has shown a growing interest in the use of hybrid wind photovoltaic (PV) systems that provide better performance compared to the use of a single component due to complementarity in meeting electricity demand. Over the past twenty-five years, hundreds of articles have addressed the topic of hybrid systems considering different configurations and final uses and, over the past decades, many reviews have made a comprehensive summary of various results obtained. However, some reviews deal with the research in a too general and qualitative way, without providing quantitative data, and other reviews are too focused on a specific topic aspect. To provide a qualitative-quantitative prospect of the research trend in the last twenty-five years, the present work is aimed at carrying out a literature review and statistical analysis starting from data extracted from the 550 most relevant and recent articles concerning hybrid systems, published between 1995 and 2020. The review aim was to produce an upgradable matrix literature database that schematizes the content of all articles in terms of different categories, such as the geographical distribution, their component configurations, operating mode and the auxiliary components used to support it, their intended uses and study methodologies (simulation, experimental, economic, energy, environmental and social analysis etc.) and software used. In addition, all the optimization algorithm, energy, economic, environmental and social indicators available in the literature were extracted and elaborated to identify the most used. The 550 articles were analysed, compared, and classified into several categories to provide an overall framework of the state of the art. The objective is to clearly and appropriately show important trends and findings in the development of hybrid wind and solar PV experimental, simulation and optimization projects. Data are elaborated to obtain a statistical analysis for each category or a combination of categories. In particular, the analysis highlighted that research is more focused on testing systems in warm or temperate localities, with the Koppen climate groups B and C prevalent over the others. From the geographical point of view, Asia is the continent most involved in world research (with China, India and Iran the first three countries for total publications produced). However, also in other parts of the world, a growing interest was noticed in this technology. The prevalent tested system configuration mode is the stand-alone hybrid systems, in a wide variety of climates and especially for residential uses. Simulations are mostly implemented in the analysed publications, mainly through HOMER and MATLAB software. Parametric analysis is widely used for optimal system design with a large variety of techniques. In particular, the system performance is examined mostly from an energy point of view. Economic analysis is also very common, alone or in combination with energy analysis. The most frequently used optimization algorithms are the particle swarm optimization (PSO) and genetic algorithm (GA), while the loss of power supply probability (LPSP) and renewable fraction (RE) for the energy analysis, the net present cost (NPC) and cost of energy (COE) for the economic analysis and the emissions (E) of CO2 for the environmental analysis are most widespread indicators. Finally, an analysis on the size of the system components is performed to study which renewable source is more preferred at low and high installed power, for stand-alone, grid-connected systems and overall, considering different intended uses. The analysis highlights that PV systems are preferred at low installed powers, especially for residential use and stand-alone mode, while wind systems, in addition to being extensively used for low installed powers, demonstrates higher employment compared to PV systems as the power increases. The paper findings and upgradable matrix literature database are proposed as a valuable tool for engineers, experts and national and international policymakers.

This dataset supports the research article “Complete greenhouse dynamic simulation tool to assess the crop thermal well-being and energy needs” [1] . In the agricultural sector, the use of energy can be very intensive [2] and the simulation of solar greenhouses is a very complex work [3] . This dataset provides the results of thermal modeling and dynamic simulation of a solar greenhouse considering simultaneously several thermal phenomena. The analysis was performed by TRNSYS 17 software (TRaNsient SYstem Simulation). The results obtained consider different phenomena that affect the thermal behavior of the greenhouse, including evapotranspiration produced by plants, heat exchange with the soil and the presence of artificial lights. Different models are presented for the calculation of the convective coefficient that best suits the presence of glass surfaces, considering the different discretization of the internal volume (single thermal zone and twenty thermal zones). The parameters that influence the thermal behavior of the greenhouse are analyzed on an hourly basis, the model has been validated with EnergyPlus. The data allow the researcher to choose a suitable greenhouse model in the case of free-floating model or in the presence of an air conditioning system.

Greenhouse crops represent a significant productive sector of the agricultural system, one of the main problems to be addressed is indoor air conditioning to ensure thermal well-being of crops. This study focuses on the ventilation analysis of solar greenhouse with symmetrical flat pitched roof and single span located in a warm temperate climate. This work proposes the dynamic analysis of the greenhouse modeled in TRNsys, simultaneously considering different thermal phenomena three-dimensional (3D) shortwave and longwave radiative exchange, airflow exchanges, presence of lamps with their exact 3D position, ground and plant evapotranspiration, and convective heat transfer coefficients. Several air conditioning systems were analyzed, automatic window opening, controlled mechanical ventilation systems (CMV) and horizontal Earth-to-Air Heat Exchanger (EAHX) coupled with CMV, for different air volume changes per hour. In summer, the exploitation of the ground allows having excellent results with the EAHX system, reducing the temperature peaks of up to 5 &deg, C compared to the use of CMV. In winter, it is interesting to note that, although the EAHX is not the solution that raises the temperature the most during the day, its use allows flattening the thermal wave more. In fact, the trend is almost constant during the day, raising the temperature during the first and last hours of the day.

One solution to achieving a large scale distribution, transportation and storage of renewable energy is methanol production from renewable-based power plants integrated with hydrogenation. In this study, a novel non-combustion heat-carrier biomass gasifier system is proposed, coupled with a large-scale solar power plant and alkaline water electrolysis system, for methanol production from syngas, water and carbon dioxide. Aspen Plus, MATLAB and TRNSYS are used to simulate and assess the performance of each component of the proposed system, under different climatic conditions of Toronto, Canada, and Crotone, Italy. In both localities, the best energy performance that minimizes the grid energy interaction factor is obtained with a photovoltaic station of 50.4 MW coupled to biomass gasification, which leads to 0.60 kWh and 0.57 kWh, respectively, in Toronto and Crotone, of electricity sent to or drawn from the grid for each kWh required by the electrolyser. However, higher profitability may be achieved in both localities with a single biomass gasification system which brings an enhanced benefit of 0.56 M€ in Toronto and 0.44 M€ in Crotone for each kW installed. It is expected that the developed modelling approach and these four newly formulated dimensionless indicators, i.e., the satisfied load fraction, utilization factor, grid energy interaction factor, and grid economic interaction value can be used to evaluate large-scale integrated renewable-based power systems.

Artificial Neural Networks (ANNs) are proposed for sizing and simulating a clean energy community (CEC) that employs a PV-wind hybrid system, coupled with energy storage systems and electric vehicle charging stations, to meet the building district energy demand. The first ANN is used to forecast the energy performance indicators, which are satisfied load fraction and the utilization factor of the energy generated, while the second ANN is used to estimate the grid energy indication factor. ANNs are trained with a very large database in any climatic conditions and for a flexible power system configuration and varying electrical loads. They directly predict the yearly CEC energy performance without performing any system dynamic simulations using sophisticated models of each CEC component. Only eight dimensionless input parameters are required, such as the fractions of wind and battery power installed, yearly mean and standard deviation values of the total horizontal solar radiation, wind speed, air temperature and load. The Garson algorithm was applied for the evaluation of each input influence on each output. Optimized ANNs are composed of a single hidden layer with twenty neurons, which leads to a very high prediction accuracy of CECs which are different from those used in ANN training.

The data describe supplementary materials supporting the research article entitled “Worldwide geographical mapping and optimization of stand-alone and grid-connected hybrid renewable system techno-economic performance across Koppen-Geiger climates” (Mazzeo et al., 2020). Hybrid renewable energy systems are increasingly adopted worldwide as technically and economically effective solutions to achieve energy decarbonization and greenhouse gas reduction targets. This data article includes the results of worldwide techno-economic optimization of stand-alone and grid-connected photovoltaic-wind hybrid renewable energy systems designed to meet the electrical energy needs of an office district. The technical simulations have been performed in TRNSYS 17 (Transient Energy System) environment. A total of 48 different locations around the world have been chosen across Koppen-Geiger climates with different latitudes and homogeneously distributed over the whole globe, considering very different climates. The analyses have been conducted for 343 different system power configurations, considering both stand-alone and grid-connected systems. A total of 16464 dynamic simulations were performed, summarized in yearly energy output from each component and in energy and economic indicators.

Greenhouse technology is an important energy consumer sector representing an indispensable solution for modern methods of crop production. In the greenhouse envelope and system design phase, thermodynamic performance simulation tools are required. The greenhouse simulation is still a very complex task despite many building tools are available in the literature. This work aims to overcome this gap by proposing a reference methodology to accommodate the building TRNSYS software for a greenhouse able to consider simultaneously different thermal phenomena with detailed modelling of: dense volume discretization, 3D shortwave and longwave radiative exchange, air flow exchanges, presence of lamps with their exact 3D position, ground and plant evapotranspiration, and convective heat transfer coefficients. A standard hourly simulation of the one-zone greenhouse was validated with another recognized tool, showing excellent agreement throughout the year. The main parameters affecting the greenhouse thermal balance were investigated in both a free-floating and continuous regime. The investigation has shown that a standard simulation is accurate to only reproduce the thermal response in a free-floating regime; instead, the detailed simulation has led to overall cooling and heating energy needs in the continuous regime, respectively, of 51.4 kWh/m3 and 49.1 kWh/m3, avoiding to obtain very high errors.

In the last years, a significant interest in research in stand-alone (SA) and grid-connected (GC) photovoltaic (PV)-wind hybrid renewable energy systems (HRES) is observed for their complementary in the satisfaction of the electrical energy demand in many sectors. However, direct comparisons between the techno-economic performance of two system modes under the same operating conditions are rarely carried out. Additionally, most of the researches are limited to specific weather conditions. This work aims to bridge the lack of this type of investigations providing a worldwide techno-economic mapping and optimization of SA and GC PV-wind HRES to supply the electrical demand of an office building district. For this purpose, energy and economic optimization problems were formulated to find the optimal SA and GC systems worldwide among 343 HRES system power configurations located in 48 different localities, uniformly divided in the sub-group of the Koppen classification. The energy reliability and economic profitability of optimal systems were geographically mapped worldwide. In general, the energy or economic optimizations of SA HRES do not lead to highly profitable systems; instead, feed-in-tariff to sell the energy in excess assures viable GC HRES in many localities. However, economically optimal SA and GC HRES, respectively, do not everywhere comply with the threshold value of 70% of the satisfied energy required by the load and are characterized by a high level of energy exchanged with the grid. The study highlighted that the most suitable climate conditions to install a SA HRES are: (i) Toamasina (Madagascar) from an energy point of view, with 76% of load satisfied and 76% of the energy generated utilized to supply the load; (ii) Cambridge Bay (Canada) from an economic point of view, with 11.1% of the capital cost recovered each year; instead, the most suitable climate conditions to install a GC HRES are: (iii) New Delhi (India) from an energy point of view, with 48% of energy exchanged with the grid per each kWh required by the load; (iv) Lihue (Hawaii, United States) from an economic point of view, with 24.3% of the capital cost recovered each year.

The growth of economies and the world population has led to an increase in the electricity demand, toward a disproportionate use of fossil fuels. The PV-wind hybrid system is considered an optimal solution in terms of technical efficiency and costs to reduce the use of fossil sources. The strong variability of renewable energies generated by solar and wind systems in different locations around the world sometimes leads to the need to use battery storage systems. In addition, the self-consumed energy produced by the hybrid system is strongly dependent on the load trend. Owing to the strong influence of the climatic conditions on a hybrid system energy performance, its optimal sizing is a very complex issue that must be addressed in each weather condition. This paper presents an energy feasibility study of a PV-wind-battery hybrid system considering different yearly climatic conditions in the world, according to the Koppen classification. The system is used to supply electrical energy to a district composed of five office buildings. The electrical load consists of artificial lighting systems, electrical office devices and electric vehicle charging stations. The effects produced by different yearly climatic conditions on three hybrid systems, characterized by the same overall nominal powers and different photovoltaic and wind nominal powers, were investigated. TRNSYS 17 was used for the dynamic simulation of the hybrid system. The overall aim is to identify the most proper climatic conditions by means of the optimization of several energy indicators: maximization of the self-consumed renewable energy and of the renewable energy produced utilized to supply the load, namely minimization of the energy imported from and exported to the grid. For this issue, a global indicator, that measures the energy exchange of the hybrid system and load with the grid, is proposed to select the optimal trade-off localities and hybrid systems.

This paper presents thermal and energy analysis of a multilayer panel in bio-based cork material and natural phase change materials (PCMs) for the development of prefabricated, recyclable and energy-efficient and autonomous building modules. For this purpose, a calculation tool is developed for the dynamic simulation of the thermal and energy behaviour of the sandwich panel. In particular, through an extensive parametric survey, the panel is sized with the identification of the arrangement of the layers, PCM temperature, and layer thicknesses to optimize the insulating and damping properties, considering typical climatic conditions of the Mediterranean climates of Southern Italy. From the conducted simulations, the types of sandwich panels that have the best insulating and storage characteristics for the building module construction were chosen. The results of these simulations will be used in future research for the preliminary design of tests to be carried out in a climatic chamber and to build a building module in real conditions to be constantly monitored through the automatic instrumental survey of internal and external physical quantities such as temperature, humidity and radiant temperature.

For the design of new buildings or buildings undergoing major renovations, the use of building performance simulation (BPS) tools is a key instrument to sizing the envelope or to select the best solution to be integrated. Nowadays, many BPS tools are available and are used by researchers and designers, each of which was independently validated, by considering different operating conditions, and rarely were directly compared in the same conditions. The objective of this work is to evaluate the prediction accuracy of the most popular BPS tools, namely TRNSYS, EnergyPlus and IDA ICE, by means of a comparison of the simulated results and the experimental measurements detected under real operating conditions. For this issue, two different small-scale solar test boxes (STBs) with one glazed wall exposed to the outdoor environment of Rome were employed for the experimental investigation. The envelope of the reference STB is insulated and made by conventional materials. In the other case, the STB floor is equipped also with a commercial phase change material (PCM) panel. Both STBs were equipped with a data acquisition system to detect the internal air temperature, the glass external and internal surface temperature and, for the PCM-based STB, also the PCM floor internal surface temperature. A wide description and comparison of the mathematical models used by the three BPS tools are provided, followed by a geometric, weather data, technical and heat transfer parameters alignment was developed to put all the tools in the same conditions. Three different experimental campaign periods were considered and used for the evaluation of each BPS tool accuracy. Some common accuracy indices were used for the comparison, such as the R2, RMSE and normalized RMSE, and an overall accuracy index that summarizes the previous ones in the different experimental campaign periods. The results have shown have highlighted the most accurate mathematical models for the prediction of the dynamic thermal behaviour of the STB in the absence and presence of a PCM. In the absence of PCM in the STB, all the three tools are comparable providing high overall accuracy index in all periods with a rank variable as a function of the period owing to the different treatment of the solar radiation modelling. In the presence of PCM in the STB, IDA ICE leads to the highest overall accuracy index in all periods. Unlike to IDA ICE, TRNSYS and EnergyPlus do not take into account the PCM hysteresis phenomenon. Instead, TRNSYS model provides the worst accuracy since it neglects both hysteresis and phase change temperature range, that is instead implemented both in IDA ICE and EnergyPlus. However, TRNSYS predictions can be retained acceptable for a preliminary evaluation since only low data and very low computational cost is required.

The implementation of phase change materials PCMs in the building sector has been recently regarded as a valuable strategy in order to achieve nearly Zero Energy Buildings. If properly employed in the internal partition, the PCM layer can increase the thermal storage capacity of the building with consequent reductions of air-conditioning energy requirement. Furthermore, an adequate thermal mass of internal walls can help in attenuating the indoor air temperature drop consequent to the shutdown of the air-conditioning system in winter condition as well as attenuating a temperature rise in summer. These aspects are amplified in highly-glazed buildings, where owing to the solar radiation entering through the glazed surfaces, the surface temperatures of the internal walls are highly variable and it is thus possible to exploit the phase change. In this study, the energy performances of highly-glazed buildings with PCM integrated in the internal walls were evaluated by a parametric analysis conducted by means of dynamic numerical simulations. A modular two-story reference building, with a highly glazed external envelope, located in Rome was investigated considering three different typologies of external opaque walls, different volumes of PCM integrated in the internal walls and several values of melting temperature in the summer and winter seasons. The simulations were conducted with the aim to assess the thermal energy requested for heating and cooling and to determine a temperature deviation index to quantify the ability of PCM to maintain the indoor air temperature at acceptable levels, when the system is not operating. The results of the analysis showed, both in insulated and non-insulated buildings, in which conditions in a warm Mediterranean climate, the phase change materials can mitigate the energy demand associated with the building air conditioning and temperature deviation in the environments when the system is switched off.

The development of hybrid renewable systems is an economically competitive solution to reach energy decarbonization and reduction of greenhouse gasses. Based on the literature, energy, economic and environmental indicators were rarely simultaneously employed in the optimization of a hybrid renewable system. In addition, there is no procedures or a set of indicators to be applied uniformly in all applications for the shared analysis. The paper presents a novel energy-economic-environmental multi-criteria decision-making in the optimization of a hybrid renewable system, based on a new set of dimensionless indicators, proposed as a standard for future applications. The procedure compares the entire PV-wind-battery system configuration with the PV-wind, PV-battery and wind-battery system sub-configurations. A width parametric and multi-optimization analysis permit the identification of the most proper nominal powers of each system component. The procedure proposed was applied in a Mediterranean residential building, demonstrating that some system configurations allow complying simultaneously with at least two of the three energy objectives proposed, the cost-optimal level and the maximum reduction of emissions, for specific values of the load. The solar source was the most suitable both from energy, environmental and economic point of view, while the use of the wind source leads to a greater system operating time in the nominal power conditions. The study pointed out and quantified that, for specific loads, PV, wind and battery powers, the development of specific incentives for wind systems and of battery systems with a higher lifespan can help to make the hybrid systems more economically competitive.

The Italian Pediatric Network is now 8 years old. The number of pediatric Departments has increased from the 19 that in 2006 began a feasibility study of the project, to the 129 of today. The objectives of the network are: scientific research, surveillance of rare events, monitoring of complex phenomena, standardization of diagnostic criteria and therapeutic processes, creation of a hospital network capable of allowing a fast and profitable exchange of informations, evaluation of the degree of implementation of clinical Guide Lines. The Network was created by the Working Group for the Accreditation and Quality Improvement (GSAQ) of the Italian Society of Pediatrics Clinical. Date are recorded at the time of discharge by a single operator for each hospital and loaded into anonymous electronic case report forms, different for each pathology, prepared with the help of subspecialty Scientific Societies and available in the Pediatric Network website [http://networkpediatrico.sip.it]. It is not possible to report here all the results obtained from the analysis of the data concerning the first four pathologies investigated (idiopathic trombocytopenic purpura, diabetes at onset, bacterial meningitis after the neonatal period, acute asthma after the second year of life). We will present just a few data on the fifth pathology: acute gastroenteritis in children below 5 years of age. 31 centers filled 612 case report forms in 7 months. It is interesting to compare the diagnostic and therapeutic policies of the partecipating units with the indications of the ESPGHAN Guide Lines. The appropriateness of admissions was rather low, beeing only 42,5% altogether, and minimal for patients admitted under pressure from the family, 2%. Appropriateness of treatments: only 2/3 of the patiens have been correctly treated showing complete or almost complete adherence to the recommendations (no more than 2 major violations or one major and two minor). Major violations were considered those that might negatively affect the course of the disease, unnecessarely increase the cost of treatment or any violation to high grade recommendations, minor violations those that did not change the course of the disease, even if not appropriate and all interventions in contrast with low grade recommendations. The most frequent violations were: microbiological studies, wrong diet prescriptions, use of unrecommended antidiarrhoeal drugs or of probiotics lacking evidence of efficacy, prescription of antibiotics. Two other report forms, concerning bronchiolitis and ALTE, will be officialy presented at this meeting and are ready to be launched in the network.