Antonino Nucara

This study presents preliminary findings from an experimental campaign conducted on a pilot-scale green hydrogen production plant powered by a photovoltaic (PV) system. The integrated setup, implemented at the University “Mediterranea” of Reggio Calabria, includes renewable energy generation, hydrogen production via electrolysis, on-site storage, and reconversion through fuel cells. The investigation assessed system performance under different configurations (on-grid and selective stand-alone modes), focusing on key operational phases such as inerting, purging, pressurization, hydrogen generation, and depressurization. Results indicate a strong linear correlation between the electrolyser’s power setpoint and the pressure rise rate, with a maximum gradient of 0.236 bar/min observed at 75% power input. The system demonstrated robust and stable operation, efficient control of shutdown sequences, and effective integration with PV input. These outcomes support the technical feasibility of small-scale hydrogen systems driven by renewables and offer valuable reference data for calibration models and future optimization strategies.

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 CO_2eq yearly emission rates was observed, with the major reduction of 2784 tCO_2eq due to maritime traffic.

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.

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.

Nowadays, energy efficiency and sustainability are the fulcra of building policies. These policies promote the use of new technologies and materials that can reduce the primary energy involved and the environmental costs of construction, guarantying at the same time a high level of comfort for the building’s occupants. Synergy between previous construction techniques and the use of new materials should be pursued by employing materials with a low environmental impact and optimal thermal insulation properties. Within this framework, new materials derived from the agriculture sector, and waste or recycling products from the industrial/agricultural sectors have been studied. The aim of this paper is to contribute to this field by analysing the insulation properties of new environmentally friendly materials composited from waste or vegetal products for their applications within the construction sector. Measurements of the thermal conductivity of nine different samples are carried out, obtaining promising results suggesting that these products can be used as feasible alternatives to the materials traditionally used for construction and insulation. However, further analyses are certainly recommended, to assess the samples’ structural properties and the influence of pre-treatments on the samples.

In the article a statistical approach to the assessment of the emission rates discharged by the road traffic in a spatial context is proposed. It exploits an indicator, the Yearly Average Vehicle, representing the pollutant emission rate of the average vehicle belonging to a specific category, and considers the statistical variability of most of the involved traffic parameters: vehicle speed and mileage travelled in the considered time period. 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.

The limitation of fossil fuel uses and GHG (greenhouse gases) emissions reduction are two of the main objectives of the European energy policy and global agreements that aim to contain climate changes. To this end, the building sector, responsible for important energy consumption rates, requires a significant improvement of its energetic performance, an obtainable increase of its energy efficiency and the use of renewable sources. Within this framework, in this study, we analysed the economic feasibility of a stand-alone photovoltaic (PV) plant, dimensioned in two configurations with decreasing autonomy. Their Net Present Value at the end of their life span was compared with that of the same plant in both grid-connected and storage-on-grid configurations, as well as being compared with a grid connection without PV. The analysis confirms that currently, for short distances from the grid, the most suitable PV configuration is the grid-connected one, but also that the additional use of a battery with a limited capacity (storage on grid configuration) would provide interesting savings to the user, guaranteeing a fairly energetic autonomy. Stand-alone PV systems are only convenient for the analysed site from distances of the order of 5 km, and it is worth noting that such a configuration is neither energetically nor economically sustainable due to the necessary over-dimensioning of both its generators and batteries, which generates a surplus of energy production that cannot be used elsewhere and implies a dramatic cost increase and no corresponding benefits. The results have been tested for different latitudes, confirming what we found. A future drop of both batteries’ and PV generators’ prices would let the economic side of PV stand-alone systems be reconsidered, but not their energetic one, so that their use, allowing energy exchanges, results in being more appropriate for district networks. For all PV systems, avoided emissions of both local and GHG gases (CO₂) have been estimated.