Electrolytic Hydrogen Production From Renewable Source, Storage and Reconversion in Fuel Cells: The System of the “Mediterranea” University of Reggio Calabria

AbstractNowadays a redesign of cities, amid the others from an energetic point of view, is taking place. It increasingly addresses the smart city model, an organic system in which infrastructures, services and technology are organized in order to achieve friendly and livable cities, combining in a single urban model environment protection, energy efficiency and economic sustainability.In smart cities buildings are nZEB and equipped with domotics applications, energy grids are smart, transports are electric, lighting is high-efficiency, hydrogen is used for energy storage, ecc. As concerns this latter, in the last periods hydrogen has increasingly shown to be particularly fit as an energetic carrier, being not pollutant, versatile, allowing production at all scales and, compared to electric battery, not requiring time consuming recharging. Anyway, due to the present relevant starting funds of its technology, its quick, effective penetration into the market still requires the necessary economic breakthroughs.Within this frame, in the paper a system aimed at hydrogen production through electrolysis from renewable source (provided by both PV and wind generators), its storage and reconversion in fuel cells is presented. The system is installed at the Mediterranea University of Reggio Calabria. Particularly, in the paper the global process taking place in the system is described, evaluating the hourly hydrogen stored amount, the power autonomy provided and the global efficiency of the process

A Case-Study Plant for a Sustainable Redevelopment of Buildings Based on Storage and Reconversion of Hydrogen Generated by Using Solar Energy

In todays process of decarbonisation and transition to a green economy based on distributed and sustainable energy production, hydrogen is considered the most promising energy carrier, thanks to its multiple properties. It is clean, versatile and has a high combustion efficiency and more importantly, renewable energy could be used as a primary source for hydrogen production near the end use point, making full use of local energy potential. Nevertheless, the current cost of its technology still requires further research and development, necessary to obtain its rapid and effective launch onto the market. Moreover, hydrogen storage and distribution infrastructures, fundamental to make it usable and competitive, are currently lacking.In this framework, the paper analyses a photovoltaic (PV) system, equipped with hydrogen storage and reconversion subsystems. The technological plant is basically aimed to be easily integrated into buildings for their sustainable redevelopment. At this stage, the presented case study was designed to supply a part of electrical needs of the Mediterranea University of Reggio Calabria.In brief, starting from the PV generation of electricity, hydrogen is obtained through electrolytic production, which is stored and then reconverted into electricity by using fuel cells. The study clearly meets the main goals of the 2030 Agenda for sustainable development. Un caso studio di impianto per la riqualificazione sostenibile degli edifici basato sullo stoccaggio e sulla riconversione dell’idrogeno prodotto usando l’energia solareNell'odierno processo di decarbonizzazione e transizione verso un'economia verde basata sulla produzione di energia distribuita e sostenibile, l'idrogeno è considerato il vettore energetico più promettente, grazie alle sue molteplici proprietà: è pulito, versatile e ha un'alta efficienza di combustione. In particolare, l'energia rinnovabile potrebbe essere utilizzata come fonte primaria per la produzione di idrogeno vicino al punto di utilizzo finale, sfruttando appieno il potenziale energetico locale. Tuttavia, l'attuale costo della sua tecnologia richiede ancora ulteriori ricerche e sviluppi, necessari per ottenere la sua rapida ed efficace penetrazione nel mercato. Inoltre, al momento le infrastrutture di stoccaggio e distribuzione dell'idrogeno, fondamentali per renderlo utilizzabile e competitive, sono ancora lacunose.In questo scenario, il lavoro analizza un sistema fotovoltaico (PV), dotato di sottosistemi di stoccaggio e riconversione dell'idrogeno. L'impianto tecnologico è pensato per essere facilmente integrato negli edifici per una loro riqualificazione sostenibile; in questa fase, il caso di studio testato era finalizzato alla alimentazione di una parte delle utenze elettriche dell'Università Mediterranea di Reggio Calabria. In breve, a partire dalla generazione fotovoltaica di elettricità, l'idrogeno viene ottenuto attraverso la produzione elettrolitica, immagazzinato e poi riconvertito in elettricità utilizzando le celle a combustibile. Lo studio è chiaramente in linea con i principali obiettivi dell'Agenda 2030 per uno sviluppo sostenibile.In todays process of decarbonisation and transition to a green economy based on distributed and sustainable energy production, hydrogen is considered the most promising energy carrier, thanks to its multiple properties. It is clean, versatile and has a high combustion efficiency and more importantly, renewable energy could be used as a primary source for hydrogen production near the end use point, making full use of local energy potential. Nevertheless, the current cost of its technology still requires further research and development, necessary to obtain its rapid and effective launch onto the market. Moreover, hydrogen storage and distribution infrastructures, fundamental to make it usable and competitive, are currently lacking.In this framework, the paper analyses a photovoltaic (PV) system, equipped with hydrogen storage and reconversion subsystems. The technological plant is basically aimed to be easily integrated into buildings for their sustainable redevelopment. At this stage, the presented case study was designed to supply a part of electrical needs of the Mediterranea University of Reggio Calabria.In brief, starting from the PV generation of electricity, hydrogen is obtained through electrolytic production, which is stored and then reconverted into electricity by using fuel cells. The study clearly meets the main goals of the 2030 Agenda for sustainable development. Un caso studio di impianto per la riqualificazione sostenibile degli edifici basato sullo stoccaggio e sulla riconversione dell’idrogeno prodotto usando l’energia solareNell'odierno processo di decarbonizzazione e transizione verso un'economia verde basata sulla produzione di energia distribuita e sostenibile, l'idrogeno è considerato il vettore energetico più promettente, grazie alle sue molteplici proprietà: è pulito, versatile e ha un'alta efficienza di combustione. In particolare, l'energia rinnovabile potrebbe essere utilizzata come fonte primaria per la produzione di idrogeno vicino al punto di utilizzo finale, sfruttando appieno il potenziale energetico locale. Tuttavia, l'attuale costo della sua tecnologia richiede ancora ulteriori ricerche e sviluppi, necessari per ottenere la sua rapida ed efficace penetrazione nel mercato. Inoltre, al momento le infrastrutture di stoccaggio e distribuzione dell'idrogeno, fondamentali per renderlo utilizzabile e competitive, sono ancora lacunose.In questo scenario, il lavoro analizza un sistema fotovoltaico (PV), dotato di sottosistemi di stoccaggio e riconversione dell'idrogeno. L'impianto tecnologico è pensato per essere facilmente integrato negli edifici per una loro riqualificazione sostenibile; in questa fase, il caso di studio testato era finalizzato alla alimentazione di una parte delle utenze elettriche dell'Università Mediterranea di Reggio Calabria. In breve, a partire dalla generazione fotovoltaica di elettricità, l'idrogeno viene ottenuto attraverso la produzione elettrolitica, immagazzinato e poi riconvertito in elettricità utilizzando le celle a combustibile. Lo studio è chiaramente in linea con i principali obiettivi dell'Agenda 2030 per uno sviluppo sostenibile

DISTRETTI ENERGETICI: UNO STUDIO SU UN QUARTIERE DI UNA CITTÀ DELL’ITALIA MERIDIONALE

Nowadays the energy transition, which implies the design of a new energy supply and distribution model based on RES, is an urgent course of action. Not only is it crucial to tackle climate change issues but it is also an opportunity to generate new technical, economic and social development possibilities. In this framework, the implementation of new structures of collective and collaborative economy, such as energy districts and communities, is encouraged by the European Union's development programs as a crucial strategy to mitigate both climate change crisis and economic inequalities as well as socio-environmental injustices. With a view to providing a contribution to the studies addressing the effectiveness of these new energy management structures, especially in Mediterranean climates, this work proposes an analysis focused on a neighborhood of a city located in the Southern Italy. The results showed that the implementation of RES in an energy district perspective, according to the feasibility granted by the neighborhood features, allowed the balance between energy productivity and needs to be reached

Assessment of the Road Traffic Air Pollution in Urban Contexts: A Statistical Approach

In the article, a statistical approach to the assessment of the emission rates discharged by road traffic in a spatial context is proposed. It exploits the ‘yearly average vehicle’, an indicator representing the pollutant emission rate of the average vehicle belonging to a specific category, considering the statistical variability of most of the involved traffic parameters: the vehicle speed and mileage travelled in the considered time. Finally, indicators assessing both the most probable value among the possible emission rates and the extent of their variability range are proposed. They may also be used to underpin decision-making processes, when the effects of different policies addressing air pollution issues are to be evaluated. Therefore, they are suitable for the analysis supporting urban planning activities, with a view to addressing and mitigating the effects and the consequences of pollution due to the transportation sector of the urban context. In addition, they can also be exploited by researchers when prediction analyses are to be performed

Modelling Indoor Radiative Heath Exchanges for Effective People Thermal Comfort and HVAC Design.

Radiative heat exchanges inside buildings are responsible of a relevant part of the thermal balance of people occupying such confined spaces and, in turn, of their thermal comfort sensations. Mean radiant temperature of the internal surfaces is supposed to affect considerably this balance but, usually, it is computed by means of too simplified relationships that significantly affect the comfort evaluations. These simplified approaches can be also accountable of a less effective design of HVAC systems. Unfortunately, an accurate evaluation of the mean radiant temperature, especially when high intensity sources are present in a given internal space, depends on the angle factors between human subjects and surrounding surfaces of the enclosure. Angle factors, on the other hand, are a direct function of the projected area factors. Presently, there is still a certain lack in the availability of simple and reliable methods capable of computing angle factors of people in assigned postures, particularly for buildings characterized by a complex geometry. On the base of experimental results, obtained by means of a photographic apparatus on purpose designed, a comprehensive algorithm is presented for assessing angle factors of people living or working in confined spaces, where heat high intensity sources are present, and sun among them. The algorithm, that is applicable to people in seated or standing postures, apart a more accurate evaluation of the indoor thermal comfort of people, allows a more effective design of heating, ventilating and air conditioning mechanical systems

Greenhouse Gas Balance in the City of Reggio Calabria and Assessment of the Effects of Measures of Emission Reduction and Absorption

Climate change and its ascertained attribution to anthropic activity need to be tackled with extreme urgency and must not be postponed. The need to reduce greenhouse gas emissions require a change in the energy paradigm, mainly affecting the construction and mobility sectors. Countries need to move towards climate neutrality with a widespread adoption of innovative models, systems, and technologies, reducing dependence on non-renewable sources and increasing energy efficiency. Measures to be adopted to achieve the prefixed decarbonization targets should involve, in addition to central governments, local communities. In this paper, in order to contribute to the definition of mitigation measures by the local administration, the balance of emissions and removal of greenhouse gases, assessed following the IPCC guidelines, for an Italian city (Reggio Calabria) on the date of 1 January 2020 is presented. Several hypotheses concerning reduction measures to be applied to the building and transport sectors, together with absorption interventions, have been developed and we have analyzed the effectiveness of each of them and their global effects on 1 January 2030. The proposed measures allow a reduction of 17% of total emissions, indicating that to reach carbon neutrality in 2050, more incisive and wide range interventions are required

Effects of the SARS-CoV-2 Pandemic on CO₂ Emissions in the Port Areas of the Strait of Messina

The Strait of Messina is characterised by a significant ship flow, especially of ferries, between its two shores. The ferry services involve four harbours, located on the Sicilian and Calabrian shores. During the epidemic emergency related to the SARS-CoV-2 virus, due to the restrictions adopted to counteract the spread of the infection, a significant reduction in ferry activities and vehicle flow occurred. These circumstances made flow data, related to different actual scenarios, available and allowed the assessment of the environmental impact of the port area. Therefore, the port area became a noteworthy case study, suited to draw conclusions regarding possible future courses of action designed to curb greenhouse gas emissions in these types of settlements. In the study, in order to assess the effect of different levels of human activity on pollutant emissions, the total CO2 emissions from ferry activities in two successive years, 2019 before the spread of the virus and 2020 when the epidemic was at its peak, were evaluated and compared. The EMEP/EEA methodology was used and, as a result, an overall reduction of 13.2% in CO2eq yearly emission rates was observed, with the major reduction of 2784 tCO2eq due to maritime traffic

A generalized model of human body radiative heat exchanges for optimal design of indoor thermal comfort conditions

Human thermal sensation depends heavily on radiative exchanges between the human body and the surrounding environment. Because these exchanges play a crucial role in the thermal balance of the human body, about 35% of the process, human thermal sensation should draw the attention of planners when designing both indoor environments and equipment. The present study aims to contribute to this field by proposing a procedure for delineating the optimal comfort conditions for occupants in most of the articulate and realistic configurations of actual indoor environments. Specifically, this procedure enables accurate assessment of the radiant field surrounding a subject in a given indoor realistic environment and considers its variability with space and time along with the presence of high-intensity radiant sources. The proposed simulation tool contains a set of algorithms in which the degree of complexity depends on the level of accuracy for modelling the radiative heat transfer between the occupants and surrounding environment. The feasibility of these algorithms for designers and researchers has also been checked for a single room characterised by the presence of windows in two different exposures. This configuration implies a complex pattern of the sun entering the room, which in turn determines relevant spatial modifications of the indoor comfort thermal conditions. Such complex situations are effectively interpreted by the proposed model. This analysis provides useful indications for suitable design of layouts of the confined space and the size of an effective heating, ventilating, and air conditioning system to limit the discomfort felt inside the room

The spatial evaluation of the radiative human body heat exchanges: An effective contribution for limiting energy consumption and achieving better indoor conditions in buildings

Radiative heat exchanges inside buildings remarkably affect the thermal balance of the human body in confined spaces and the related thermal comfort sensations of people. The mean radiant temperature is an important component of this balance. Unfortunately, it is usually computed by means of too simplified relationships, which significantly influence the comfort evaluations. Such simplified approaches are also accountable for a less effective design of HVAC systems which, in turn, could result in high energy consumption in the climatization of buildings. However, an accurate evaluation of the mean radiant temperature, especially when high intensity sources are present in a given internal space, depends on the angle factors between human subjects and surrounding surfaces of the enclosure. Angle factors, in turn, are direct functions of the projected area factors of the human body. Presently, there is still a certain lack in the availability of simple and reliable methods for computing angle factors of people in assigned postures, particularly in case of complex geometry and presence of heat high intensity sources, like sun. A comprehensive method is here introduced for evaluating the thermal comfort conditions of indoor spaces, avoiding the difficult singling out of several algorithms, dispersed in an inorganic way in the literature. A further contribution consists in the possibility of evaluating geometrically complex enclosures also in presence of direct solar radiation entering the room. Moreover, an analytical method for computing the projected area factors, based on experimental results, obtained by means of a photographic apparatus on purpose designed, is included in the methodology. An application of the method to a typical building situation in presence of direct solar radiation is also proposed