• Energy Research
• 13. Climate action close
• 6. Clean water close
• IT close
• ES close
• Polytechnic University of Turin close

The decentralization of the production sector crisis following industries in the suburbs have generated a multitude of empty containers in the medium-large Italian cities, which are abandoned, unsafe, and often dangerous for the community. From this arises the need to recover them and transform them into something else. This is not always possible or interesting for the subjects involved in the transformation. When the abandoned space is (even if only partially) polluted, then any hypothesis of transformation is stopped due to the high impact of decontamination costs, which greatly compromise the profitability of the investment. This paper deals with this issue focusing on a complex case study involving the abandoned area and the buildings of a former paint mill in the center of a typical city in the Turin metropolitan area. The suggested hypothesis is to act only on building components and external areas without any ground modification because of its contamination. Moreover, the new planned use (energy production from renewable sources to supply part of the public administration’s needs) does not foresee neither a stable presence of people nor a further consumption of land. The technical analysis of community energy needs and the subsequent economic and financial study lead to a financial sustainability over a period of about 25 years.

The development of new methods for the correct disposal of waste is unavoidable for any city that aims to become eco-friendly. Waste management is no exception. In the modern era, the treatment and disposal of infectious waste should be seen as an opportunity to generate renewable energy, resource efficiency, and, above all, to improve the population’s quality of life. Northern Italy currently produces 66,600 tons/year of infectious waste, mostly treated through incineration plants. This research aims to explore a more ecological and sustainable solution, thereby contributing one more step toward achieving better cities for all. Particularly, this paper presents a conceptual design of the main sterilization chamber for infectious waste. The methodology selected was Design Thinking (DT), since it has a user-centered approach which allows for co-design and the inclusion of the target population. This study demonstrates to the possibility of obtaining feasible results based on the user’s needs through the application of DT as a framework for engineering design.

Abstract District Heating (DH) technology is considered to be a sustainable and quasi-renewable way of producing and distributing hot water along the city to heat buildings. However, the main obstacle to wider adoption of DH technology is represented by the thermal request peak in the morning hours of winter days, especially in Mediterranean countries. In this paper, this peak-shaving problem is tackled by combining three different approaches. A thermodynamic model is used to monitor the buildings’ thermal response to energy profile modifications. An agent-based model is adopted in order to represent the end-users and their adaptability to variations of temperatures in buildings. Finally, a Reinforcement Learning algorithm is used to optimally mediate between two needs: on the one hand, a set of anticipations and delays is applied to the energy profiles in order to reduce the thermal request peak. On the other hand, the algorithm learns by trial and error the individual agents’ sensitivity to thermal comfort, avoiding drastic modifications for the most sensitive users. The experiments carried out in the DH network in Torino (north-west of Italy) demonstrate that the proposed approach, compared with a literature solution chosen as a baseline, allows to achieve better results in terms of overall performances and speed of convergence.

Abstract Recent studies suggest that the supplementation of powdered Fe° generates a positive effect on anaerobic fermentation processes but the exact relationship between metals with biological systems has not been fully elucidated. Experimental tests on dark fermentation (DF) were carried out at different Fe° concentrations. The anaerobic corrosion (AC) of Fe° and the production of H2 through DF of Organic Waste Market (OWM) were tested separately, and subsequently DF tests with Fe° at 1 g/L and 2 g/L were carried out. A macroscopic dynamic study was conducted, using Roels approach based on relaxation times (τR) to establish whether interactions between AC and DF phenomena exist. Experimental bioH2 production and Fe° AC were fit by Gompertz and saturative models, respectively to estimate τR. The results of the macro-analysis suggest that both phenomena are concurrent, with τR of the same order of magnitude, generating a positive symbiotic effect. The experimental tests of hydrogen production via DF in presence of 2 g/L of Fe° showed an increase of 46% compared with the control tests, of amount of gas and a greater H2/CO2 ratio. The results suggest an enhancement of key enzymes activity due to the action of iron increasing bioH2 production.

Abstract Driven by urbanization growth, in recent years, the relationships among energy systems and underground space are becoming more and more intense for many reasons: the severe competition in the land use, the security of energy commodities management, the need of huge infrastructures for mass and energy transportation (e.g. pipelines), the safety requirements against seismic events and eventually, economic and environmental considerations. For such reasons, nowadays underground space is becoming an extremely important as an alternative for urban areas expansion, if properly planned. In fact, a correct underground space planning strategy, together with the progressive developments of suitable integrated connections between surface and subsurface can increase the livability of cities and improve public health. Population in urban areas is expected to grow, in particular in developing economies (such as China); this phenomenon leads to an increasing pressure on urban areas to supply the growing energy needs. In fact, several end-use services should be fulfilled to provide indoor comfort in buildings, for mobility of people and goods, etc. Anyway, only a very limited amount of energy can be generated inside urban areas (from municipal solid wastes, from thermal/solar PV and heat pumps installations); as a consequence, the majority of the energy commodities are produced, converted and stored in power plants located far from cities and require huge transport infrastructures. In this paper, the cost/benefit relationship between underground and energy use is explained by reviewing main application of existing underground space utilizations for energy processes (distribution, storage and generation), as well as other innovative opportunities. From the analysis of past experiences analysis, the main conclusion is that a rational approach in urban energy planning procedures, integrating both over- and below-ground space utilizations, could help to raise the quality of energy services and it is fundamental for reaching a smarter and more resilient society. In such a new Underground Urbanism approach, the need for long-term Integrated Master Plans that propose suitable Guidelines is highlighted.

Abstract Although CSP has reached technological maturity, high capital investment and specific electricity cost remain the major development barriers. To reduce them, highly efficient, integrated, and cheaper CSP components are urgently needed. In this paper, we investigate a novel CSP plant configuration with a single-tank Thermal Energy Storage (TES) fully integrated with the steam generator. The objective of this research is twofold: i) provide a reliable model of single-tank thermal storages with integrated steam generator; ii) identify two optimized CSP plant designs to achieve best energetic and economic performances. To achieve these aims we developed a numerical model of the main system components and validated it against experimental data. This model was then integrated in a full simulation and heuristic design optimization of the plant. The results revealed that the system proposed can generate electricity in middle-Italy (Rome) at a cost of 230.25 $/MWh with a 15% reduction compared to the double tank option. Furthermore, if cogeneration is used to recover the waste heat, this system is an interesting option for users such as small districts, university campuses and hospitals. In the latter case, the optimized system pays off in 6 years and covers 80% of the heating and cooling requirements.

Finding cost-optimal solutions towards nearly-zero energy buildings in accordance with the Energy Performance of Buildings Directive (EPBD) is a challenging task. In order to reach the 20-20-20 targets, EU energy policy has introduced new ambitious levels for the large-scale spread of nearly-zero energy buildings (nZEBs) and the concept of the cost-optimal level, defined as the energy performance level, which leads to the lowest cost during the estimated economic lifecycle of the building. Consequently, building design has begun a challenge involving both energy targets and economic concerns. The aim of this research is to analyze an example building of a new single family house, using the cost-optimal methodology, in order to define how energy and economic aspects influence the preliminary design phase of the project and, in particular, the choice of the performance features of some components of the project itself, such as envelope elements and systems. The impact on energy performances of different configurations for the building envelope and heating, ventilation and air conditioning (HVAC) systems was assessed with the dynamic simulation software EnergyPlus. Finally, the costs of the different design scenarios were estimated, according to the European Standard EN 15459:2007 to establish which of them had the lowest global cost and, consequently, represents the cost-optimal level for the design configurations analyzed. In order to test the stability of the results obtained, different sensitivity analyses were carried out.

A new multizone premixed-diffusive combustion model has been developed, assessed, and applied to diagnose the burning process and emission formation in a conventional and in a premixed charge compression ignition (PCCI) diesel engine. The model is based on the Dec conceptual scheme, which considers combustion as a two-stage quasi-steady process: All fuel particles undergo a first rich premixed combustion phase, and the products complete their oxidation in close-to-stoichiometric conditions at the jet periphery through a diffusion flame. The combustion chamber contents have been divided into several homogeneous zones to which the energy and mass conservation principles were applied. The computed thermodynamic and thermochemical properties in the burned gas zones allowed a post-processing analysis to be made of the nitric oxides (NO), particulate matter (PM), and carbon monoxide (CO) formation. The model requires the in-cylinder pressure trace and other experimental engine quantities as input data and calculates the premixed and diffusive heat release rates along with the temperature and mass evolutions of the different zones. Thus, the model is not predictive but diagnostic: The objective is to interpret measured engine data in order to obtain insight into the in-chamber combustion and pollutant formation processes. The model has been tested on EGR-sweeps and under full-load conditions on the conventional engine and under a high EGR operating condition on the PCCI engine. With reference to NO emissions, the model results showed an excellent agreement with the experimental data for all the tests even when the main model parameters were kept constant for different test conditions. Good results were also obtained for the prediction of the CO and PM emission levels. Finally, for the premixed combustion zone, it was ascertained that higher local A/F ratios were required in the PCCI combustion mode than in the conventional mode as a consequence of the increase in the degree of premixing.