Marco F. Torchio’s research while affiliated with Polytechnic University of Turin and other places

In 1990, the United Nations (UN) presented the Human Development Index (HDI) as a measure of human development that considers three fundamental dimensions: a long and healthy life, being knowledgeable, and having a decent standard of living. This paper proposes some considerations about human well-being factors based on HDI analysis, also introducing some considerations on environmental pollution. As regards environmental issues, two different pollutants are considered together with their environmental costs: (i) greenhouse gas (GHG) emissions, which have an impact on a global scale, and (ii) emissions from fine particulate matter, primarily having an impact on a local scale. Thus, a new index based on the external environmental costs is proposed, and two scenarios are discussed. On the other hand, as it concerns human well-being, the results of surveys among the population are used. Furthermore, other features regarding health services and demographic aspects are taken into account, too. Italy is analysed as a case study over the last three decades. Easterlin’s considerations are verified based on the variation of perceived well-being related to the changes in GDP. The Italian case study shows that despite having achieved a satisfactory HDI level, there is a wide margin for improvement from both the environmental and the well-being standpoints.

Sustainability is an imperative of the 21st century in order to preserve the environment for the next generations, but sustainable development also requires the introduction and use of new technologies, and the related abilities for their use. The United Nations have adopted the Human Development Index HDI in order to assess human well-being. This index includes a component related to knowledge, the Education Index, which is expressed in terms of the mean schooling years. However, this information does not contain a measure of the student’s ability to solve complex problems or ability to reason, which are fundamental skills for sustainable development. In this study, an improved version of the Education Index was developed by considering the data available from the OECD’s Programme for International Student Assessment (PISA). This new index takes into account both the social impact of schooling years and the outcomes of the education systems for each country (PISA scores). As a consequence of this new Education Index, a new Human Development Index, HDI*, is proposed. Two case studies were performed, comparing the European and non-European countries, focusing on government education spending. Moreover, the trends of an energy and an environmental indicator are analyzed in relation to the HDI*.

Energy and environmental data represent fundamental information for the analysis of sustainable development. On the other hand, these aspects should be associated with economic and human dimensions in order to obtain a more holistic vision. From this perspective, some indicators are discussed and analyzed in this paper in order to assess the performance of a country. As regards the energetic aspects, the data of total primary energy supply and exergy losses were considered. The environmental aspects were taken into account by considering the greenhouse gas emissions and the particulate matter emissions. These energy and environmental data were put in relation to the GDP (gross domestic product) and HDI (human development index, a multidimensional index proposed by United Nations), respectively. So, two sets of indicators were introduced—the set E for economic properties and the set H for human aspects. A case study was conducted by analyzing a group of countries that meet two criteria: the same macro-geographical area and comparable numbers of citizens. The European area—in particular, its six most populous countries—was chosen. From the results obtained, it is possible to point out that some countries present different rankings depending on whether set E or set H is considered. Another important aspect discussed is the temporal evolution of the indicators (the interval from 1990 to 2017 was considered). Political decision-makers can be supported by the use of the indicators of set H in order to evaluate well-being related to their choices on actions related to the energy and environment. These indicators can be used both to analyze the trends of a country and to compare them with the performance of some other similar countries.

In the first part of this work, combined heat and power (CHP) criteria pertaining to energy, exergy, environmental (pollutant emission) and economic aspects, have been investigated and compared. Although the constraints in legislation usually refer to energy efficiency, primary energy savings and greenhouse gas savings, other criteria should also be taken into account in order to obtain a better evaluation of a cogeneration plant. Here particular attention has been paid to saving indexes for both an individual CHP-unit and for a CHP-system, that is the complete system with all the cogeneration units and the auxiliary plants necessary to cover the users’ demand. Five indexes, named potential indexes, have been introduced to evaluate the cogeneration potential: one for energy saving, one for exergy, two for environmental aspects (global and local scale) and one for economic aspects. Finally, some indexes analysed in the paper have been applied to a case study concerning a district heating cogeneration system, and the different behaviour of the energy-exergy, environmental and economic aspects has been discussed.

District heating CHP (combined heat and power) and distributed generation CHP have been compared in this paper on the basis of energy, environmental and economic criteria, and a deviation index has been proposed to establish, in aggregate form, what the improvement margins are for a given design choice. Three technologies that are suitable for both district heating and distributed generation have been chosen: a mature market technology, internal combustion engines, and recent entry market technologies, that is, microturbines, and fuel cells. The calculations have been based on the real heating load curve of a town in Northern Italy at the current market conditions: power and fuel prices, tax exemptions relative to cogeneration, white certificates, etc. Two scenarios have been considered: maximum energy saving and maximum present value saving. In the first scenario, district heating obtained better energy and CO2 savings than distributed generation, but critical values have been observed for local nitrogen oxides (NOx) and particulate matter emissions, when internal combustion engines are adopted. In the second scenario, all the options offer positive energy, environmental and economic savings, and the payback times are significantly reduced compared to the previous scenario. The district heating options show the best present value savings and payback times, while distributed generation is only economically viable when internal combustion engines are adopted. Microturbines leads to the best NOx savings. Finally, the comparison with an alternative separate production of heat and power has shown that there are scenarios where none of the analysed technologies leads to a significant improvement. All this information, analysed together, provides a sort of map for policy makers through which they can better orientate themselves among the different scenarios.

The well-to-wheels assessment is widely used in the automotive sector to analyze the efficiency and competitiveness of different powertrain/fuel options. The paper proposes a global index that takes into account both the energy and environmental aspects on an uniform basis, through the assignment of the costs associated to the energy and to the pollutant emissions. The European market is analyzed and other pollutants (NOx, PM and SOx) are added to the traditional well-to-wheels evaluations (energy and GHG). The proposed well-to-wheels global index offers a useful place-list that takes into account both energy and environmental aspects and, at the current market conditions, it results that the energy cost prevails (70–85%) over the environmental costs, and among the analyzed external costs, the main contribution is due to the GHG emissions. Natural gas-derived fuels seem to be the most promising. The global index for battery electric vehicle from a European mix are closely linked to the driving range. Conventional biofuels are very critical at present, while significant improvement of the well-to-wheels global index is foreseen for when new generation biofuels will be mature (2030 forecast). In short, even though the proposed global index is not an exhaustive index, it could be a useful tool for decision makers.

District heating (DH) systems, together with combined heat and power (CHP) plants, have been increasing both in number and interest over the last decade, but the environmental improvements are still controversial, because although there is usually a reduction in CO2 emissions, a positive effect concerning other pollutants is not always certain. A limited number of works that pay particular attention to the local environmental effect due to DH plants have been found in a brief overview of DH papers. The energetic and environmental impact of a new DH+CHP plant has been investigated in the present paper, where this plant has been proposed to substitute the existing heating systems. The environmental aspects concerning the local variations due to some pollutants, such as sulfur oxides (SOx), particulate matter (PM) and nitrogen oxides (NOx), are in particular taken into account. The main data necessary for the analysis and the hypotheses that are useful to simulate the behavior of the local heating plant and DH plants (e.g. efficiency, the heating demand, etc.) are discussed. A dispersion model (Gaussian model) has been used to evaluate the effect at a local scale. Finally, a case study concerning a new DH+CHP plant in Northern Italy is presented and discussed.

In this paper, starting from previous works, further analyses on district heating cogeneration systems are proposed and particular attention is given to the NOx pollutant. In addition to the mean yearly concentrations, the hourly limit values for the protection of human health are also taken into account: the 18th maximum hourly concentration is considered. The main steps necessary to characterize a district heating plant are shown and two case-studies are discussed. As far as the energetic aspects are concerned, these new plants always offer a primary energy saving, and the global environmental effects are improved due to a reduction in CO2. Local NOx emissions of a future plant do not decrease with respect to the existing emissions, and this aspect is closely connected to the type of CHP unit that is adopted (in this paper, natural gas fuelled engines). The local environmental effects due to NOx are estimated using a dispersion model, and the NOx concentrations (annual mean value and maximum hourly value) introduced by the new plant and those avoided through the non-use of existing domestic boilers are compared. For one of the case-studies emerges that some zones do not satisfy ambient air quality limits. For these reasons, a higher stack has been assumed for this critical case and the new results show that a reduction in the frequency of the overcomings, which is in agreement with expectations, can thus be obtained. The analysed case-studies have shown that even a small CHP district heating plant can produce critical aspects and a pollutant concentration analysis is a useful tool to check local environmental aspects.

This article describes a methodology and an apparatus used to evaluate the onset time of free convection in hot-wire experiments. The evaluation of the onset time is useful to obtain a measurement interval that is suitable to estimate the thermal properties of a fluid. If a pure conduction regime is present, the hot-wire temperature increment versus time is a straight line in a semilog plot, whereas the convection effect induces a deviation from this trend. An algorithm based on the F test is proposed to evaluate the onset time of free convection. The experimental facility has the particular feature of allowing an easy change of the hot-wire inclination angle up to 118.3 mrad. The wire is kept in a tilted position by a permanent horseshoe magnet, and the tilting angle from the vertical is measured by a theodolite. Some testing results using water are discussed for vertical and inclined wires. A good agreement between the experimental onset times and the theoretical ones is found in the case of a vertical wire.

The paper describes an experimental analysis on the effect of cathode flow stoichiometry on the electrical performance of a PEMFC stack. The electrical power output of a PEMFC stack is influenced by several independent variables (factors). In order to analyse their reciprocal influence, an experimental design methodology was adopted in a previous experimental session, to determine which factors deserve particular attention. In this work, a further experimental analysis has been carried out on a very significant factor: cathode stoichiometry. Its effects on the electrical power of the PEMFC stack have been investigated. The tests were performed on a 3.5kWel ZSW stack using the GreenLight GEN VI FC Test Station. The stack characteristics have been obtained running a predefined loading pattern. Some parameters were kept constant during the tests: anode and cathode inlet temperature, anode and cathode inlet relative humidity, anode stoichiometry and inlet temperature of the cooling water. The experimental analysis has shown that an increase in air stoichiometry causes a significant positive effect (increment) on electric power, especially at high-current density, and up to the value of 2 stoichs. These results have been connected to the cathode water flooding, and a discussion was performed concerning the influence of air stoichiometry on electrode flooding at different levels of current density operation.