Development of a greenhouse gas accounting GIS-based tool to support local policy making - Application to an Italian municipality

Climate change is the issue of the century and, according to Agenda 21, local actions are essential to impact global mitigation of greenhouse gases (GHG) emissions (“think globally, act locally”). However, in order to plan and implement effective, sustainable actions, local authorities need detailed information on their GHG emissions and their sources. This paper presents the work that led to the development of a GIS-based tool for local GHG accounting, which provides data for local decision-makers in an innovative manner different from traditional GHG inventories. The original aspects of the study are the geo-referencing of all results and the possibility of calculating all emissions (carbon sources) and removals (carbon sinks) with input data of different accuracy

Acoustic optimization of windows and doors through sound intensity measurements

ISO 140-5 defines the procedures to evaluate the sound insulation of façades obtaining the global value D2m,nT,w. Moreover, each component of the façade can be characterized in laboratory by means of its airborne sound insulation R using the methodology given by ISO 10140, and the weighted sound reduction index RW calculated using ISO 717-1. It is possible to deepen the analysis of the façade components behavior using sound maps obtained through sound intensity measurements. These are used to locate sound leakages and, in general, to have a clear view of the performance of the tested element sub-components. The paper, after a brief description of the method and the instruments used, presents the results of several campaigns executed on different moveable parts of a building’s envelope: windows, doors and minor components such as rolling shutter boxes. Thanks to the various case-studies presented, it is demonstrated how the sound intensity measurements – using P-P probes - could bring to not negligible improvements both on the design and the installation of the investigated components. Finally, a different technique for measuring sound intensity passing through a window is presented, using a P-U (Pressure - Velocity) probe

Comparative analysis of solar power technologies through Life Cycle Assessment approach

Through the Life Cycle Assessment (LCA) approach, a comparative environmental analysis was carried out to evaluate both photovoltaic (PV) and concentrated solar power (CSP) technologies. The analysis was performed on the basis of the same key parameters (location, solar radiation, etc.), considering three different power plants: a PV plant with polycrystalline Silicon modules, a Parabolic Through CSP plant (PT-CSP) and a Central Tower CSP plant (CT-CSP). All the plants are equipped with solar tracking systems. Manufacturing processes of materials and components of the power plants, their transportation, the operation and the end of life of the power plants themselves are considered, while construction activities, maintenance and dismantling activities are omitted. The functional unit chosen is 1 kWh of electricity produced by the plant and the following key indicators were calculated to make the comparison: Greenhouse Gases (GHG) emissions over a 100 years time horizon and Energy Payback Time (EPT). The analysis shows an overall impact of the PV plant significantly higher than both CSP plants: GHG emissions for PV plant are equal to 34.4 gCO2eq/kWh, while for PT-CSP and CT-CSP the values are, respectively, 20.6 gCO2eq/kWh and 14.2 gCO2eq/kWh. The trend in results is the same for EPT, in fact it results 2.1 years for PV, 1.2 years for PT-CSP and 0.7 for CT-CSP. The results are also in agreement with the data reported in literature

Experimental and theoretical investigation of solar driven absorption chillers

Within the Vigoni Programme for cooperation between Italian and German universities, the University of Perugia and the Technische Universität Berlin have been carrying out in the last years a joint research programme on two similar solar driven absorption plants, with evacuated tube solar collectors and Water-Lithium Bromide thermosyphon absorption refrigerators of the same manufacturer, but of different cooling capacity. The performance – especially in part-load - of these systems is not as satisfactory as it should be theoretically, so the research focused on the phenomenon of the overflow of the refrigerant, in order to improve this situation and to forward the technology. A detailed analysis of the thermodynamic process was conducted, employing comparable and shared measurement chains; the results suggested a control strategy, which balances the machine in such a way that the evaporator is neither overflowing nor running dry

Comparison of two similar solar driven absorption chillers for different values of solar radiations

Within the Programme Vigoni for cooperation between Italian and German universities, a research work has been carried out between the University of Perugia, Industrial Engineering Department and the Technische Universität Berlin, Institut für Energietechnik on the theoretical analysis and the operational experience of solar cooling plants. The laboratories of the two universities house two similar solar driven absorption plants, with evacuated tubes solar collectors and Water-Lithium Bromide thermosyphon absorption refrigerators of the same manufacturer, but of different cooling capacity. In both plants measurement facilities allow to record in real time all the main operating parameters of internal and external circuits (temperatures, pressures and flow rates). It is known that the main problem for such solar chiller system is to have the highest feeding temperature when the refrigerating load request is greater since many parameters influence their correlation. Therefore, the aim of research has been focusing on the study of feeding temperature variations versus solar radiation and some system parameters, for both absorption chiller, conditions to find the optimal one

Smart materials: Cementitious mortars and pcm mechanical and thermal characterization

Climate change (CC) is predominantly connected to greenhouse gas (GHG) emissions from the construction sector. It is clear how it is necessary to rethink construction materials in order to reduce GHG emissions. Among the various strategies proposed, recent research has investigated the potential of smart materials. This study in particular aims to develop an innovative building component that combines high energy performance with reduced thickness and weight. For this reason, the potential of Phase Change Materials (PCM) in cement-based mixes is investigated, comparing the performance of a traditional mix with two innovative mixes made with the addition of 3% and 7% PCM. This work characterizes the new material, analyzing its mechanical and thermal performance, highlighting how the mix strength decreases as the PCM ratio increases; however, both mixes may be considered suitable for masonry structures and may be classified as M5 and M15. Furthermore, from the analysis of the thermal performance, it emerges that the mix presents good behavior in terms of insulating properties

Energy and exergy analysis of glycerol combustion in an innovative flameless power plant

The consequence of biodiesel consumption and production growth involves a significant surplus of glycerol, which is a source of concern in the energy field. The glycerol poor Low Heating Value and its ineffective combustion, with the possible risk of producing toxic acrolein, reduces the interest to use it as a fuel. The present study reports the energy and exergy analysis of an innovative oxy-combustion plant fed by glycerol. Oxy-combustion allows to reach high temperatures, limiting the pollutants emission linked to the glycerol combustion such as acrolein. The study consists on evaluating the actual performance of the plant, in comparison with other conventional fossil fuel-fed energy systems. Experimental measurements of pressure, temperature and flow rate were acquired to calculate both the system energy and exergy efficiencies of the main components; namely, reactor, quencher and boiler. Results show encouraging performance of the plant (energy efficiency 65%, exergy efficiency 22%), if compared with traditional fossil fuels combustors, which further contributing to the energy output of the biodiesel production chain. Finally, the CO2 generated from the combustion is easily sequestrated, therefore, the results valorise the glycerine as biofuel for energy production