200 research outputs found

    Evaluation methodology for energy efficiency measures in industry and service sector

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    Directive 2012/27/EU, transposed in Italy with Decree of 4 July 2014 No102, a common framework of measures for the promotion of energy efficiency in European Union, is an innovative tool for improvement of energy efficiency and also necessary to undertake main objective of European Union (save 20% of primary energy consumption by 2020). Large enterprises and energy-intensive firms, except those having an energy management system (EnMS) according to ISO 50001 or compliant with EMAS Eco-Management and Audit Scheme or ISO 14001 fall under obligations and must be carry out energy audits every 4 years starting by December 2015 having "SMART" requirements: be Specific, Measurable, Accessible, Realistic, Time related. The analysis on a sample of Italian companies, mainly of small and medium enterprises (SME) in industry and the service sector, was conducted. Energy audit was carried out to identify Energy Company Profile, rationalize energy consumption to increase energy efficiency, assessing potential for energy savings and reducing of environmental impact. For any business context a series of energy efficiency measures has been proposed, selecting high profitability energy saving options by applying a priority criterion. Technical and economic indicators were reported on best practices focusing on tertiary sector and also industry. The study, starting from the feasibility assessments, aims to establish a possible correlation between energy performance indicators (EnPIs) and a limited number of parameters of the energy systems, in terms of production, operation and power consumption. Comparative assessment of energy-saving measures provides an useful method for assessing applicability of standard energy-saving measures in similar contexts and cost-effectiveness of solutions, as a function of a limited number of parameters

    Mobile Platform of SRF Production and Electricity and Heat Generation

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    Abstract The technological frontier is ripe for action on the cycle of municipal waste at local level through the optimization of existing treatment processes, adapting to European Union directives. The study concerns the analysis of the waste cycle in order to rationalize the current paths of the waste by adapting to EU directives, with a view of the entire supply chain - from the delivery to the energy production (WtE, Waste to Energy) – with a intermediate stage of SRF (Solid Recovered Fuel) production. The DIMA has developed an innovative platform for MSW treatment (unsorted and not), based on newly developed technologies that enables its weight and volume reduction and the transformation in SRF high quality, by achieving consistent chemical-physical and particle size parameters through the innovative technology of mechanochemical micronization. This standardized fuel product is therefore suitable for energy recovery within the platform using the most advanced gasification process. The study aims at developing a mobile demonstration plant of 100-200 kWe for energy recovery from waste in cogeneration by conversion of MSW into SRF through a system of characterization, treatment and recycling based on a highly innovative mechanochemical refining system. The SRF is enhanced through more advanced gasification process and it can used for the production of electricity and thermal energy. The production, the gasification and the syngas combustion take place in modular units arranged in appropriate mobile units (containers) appropriately configured, to fully meet the objectives of a sustainable policy management and security of waste. b Unit 1 (waste treater - SRF producer) is developed to operate the transformation of industrial waste in SRF for subsequent gasification inside unit 2 (Boiler Gasifier). It carries out a pre-treatment and mechanochemical micronization waste treatment. The SRF is reduced into pellets to be introduced into the 2 (boiler gasifier) to its gasification (syngas production). The pellet (auxiliary unit 4, pellettizer) is gasified in the unit 2 and enriched in order to obtain synmethan gas for producing electricity in the cogeneration unit 3 (energies production)

    Impact of carrier dynamics on the photovoltaic performance of quantum dot solar cells

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    The study presents a theoretical investigation of the impact of individual electron and hole dynamics on the photovoltaic characteristics of InAs/GaAs quantum dot solar cells. The analysis is carried out by exploiting a model which includes a detailed description of quantum dots (QD) kinetics within a drift-diffusion formalism. Steady-state and transient simulations show that hole thermal spreading across the closely spaced QD valence band states allows to extract the maximum achievable photocurrent from the QDs; on the other hand, slow hole dynamics turns QDs into efficient traps, impairing the short circuit current despite the extended light harvesting provided by the QDs

    Photovoltaics Noise Barrier: Acoustic and Energetic Study

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    AbstractIn the light of global warming, renewables such as solar photovoltaics (PV) are important to decrease greenhouse gas emissions. An important issue regarding implementation of solar panels on large scale, is the limited available area. Therefore, it can be interesting to combine PV with alternative applications, as a ways of not requiring “additional” space. One example is a photovoltaic noise barrier (PVNB), where a noise barrier located along a highway or railway is used as substructure for PV modules. Even though PVNB is not a novel concept, in this paper it is studied the best shape of the barrier to optimize the acoustic and energy properties

    Homeless persons and migrants in precarious housing conditions and COVID-19 pandemic: peculiarities and prevention strategies

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    Homeless persons and migrants in precarious housing conditions are vulnerable populations that have been peculiarly impacted by the Coronavirus Disease 19 (COVID-19) pandemic. These populations are more at risk of contracting COVID-19 as they often find it difficult to adhere to public health directives and, if exposed, may be more susceptible to illness or death due to the higher prevalence of underlying physical and mental comorbidities compared to the general population. In addition, vulnerable populations may have limited access to essential diagnostics and treatments, thus leading to untreated COVID-19 cases and their development into more severe forms. Health, social and government agencies should collaborate to develop services that support these communities, in accordance with the World Health Organization principles. Migrant and homeless centers have a central role, as they provide a significant contribution to prevent infection spread and favor access to early medical treatment to those affected, thus preventing more severe forms of infection

    Variational control approach to energy extraction from a fluid flow

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    Energy harvesting from the environment is an important aspect of many technologies. The scale of energy capturing and storage can involve the power range from mWatt up to MWatt, depending on the used devices and the considered environments (from ambient acoustic and vibration to ocean wave motion, or wind). In this paper, the wind turbine energy harvesting problem is approached as an optimal control problem, where the objective function is the absorption of an amount of energy in a given time interval by a fluid-flow environment, that should be maximized. The interest relies on outlining general control models of fluid-flow-based extraction plants and identifying an optimum strategy for the regulation of an electrical machine to obtain a maximum-efficiency process for the related energy storage. The mathematical tools are found in the light of optimal control theory, where solutions to the fundamental equations are in the frame of Variational Control (the basis of the Pontryagin optimal control theory). A special problem, named Optimally Controlled Betz’s Machine OCBM-optimal control steady wind turbine, is solved in closed form, and it is shown that, in the simpler steady case, it reproduces the maximum efficiency machine developed in Betz’s theory

    Assessment of Natural Resources Use for Sustainable Development - DPSIR Framework for Case Studies in Portsmouth and Thames Gateway, U.K.

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    This chapter reports on the uses of the DPSIR framework to assess the sustainability of the intertidal environments within the two UK case study areas, Portsmouth and Thames Gateway. It focuses on statutory conservation areas dominated by intertidal habitats. Two are located in Portsmouth (Portsmouth and Langstone Harbours) and four in the Thames Gateway (Benfleet Marshes, South Thames Estuary, Medway Estuary and the Swale in the Thames Gateway). Based on the reduction of a number of pressures and impacts observed in recent decades and the improvement of overall environmental quality, all six SSSIs are considered to be sustainable in the short and medium term. In the future, it is possible that the impacts of climate change, especially sea-level rise, might result in further reduction in the area and/or quality of intertidal habitats. Further integration between conservation and planning objectives (both for urban development and management of flood risk) at local level is needed to support the long-term sustainability of intertidal habitats

    Energy Enhancement of Solid Recovered Fuel within Systems of Conventional Thermal Power Generation

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    Abstract The main objective of this article is to verify the feasibility, in terms of technical and economical issues, of a new refuse-derived fuel SRF (Solid Recovered Fuel) to be used as a new fuel in a thermal power station or in an incineration plants. By means of the innovative micronization technology it is possible to produce SRF suitable for the technical specifications of the plants which, taking into account appropriate modifications, could be reconverted and not decommissioned. The present energy supply scenario shows a partial contraction of the activities of power plant thermal generation despite an increase of the power demand and despite one of the highest energy cost in Europe. It is likely to surmise a gradual stall of such activities and finally the decommissioning due to the fact that plants will turn out to be not economically productive. On the other hand, it is now necessary to promote adequate policies for sustainable waste management. An opportunity in this sense is represented by the smart usage (made possible through innovative manufacturing processes) of the SRF as an energy source. The tests conducted on the innovative chemical-mechanical micronization technology showed an average energetic cost of 30 kWh/ton, and an average production cost of 15 €/ton for the 0.5 mm size. Combustion tests showed a good environmental and combustion performance. In this article, the refuse-derived fuel (which is governed according to the Decrees of the Ministry of Environment, Land and Sea) has been obtained through an innovative technology of chemical-mechanical micronization. We have also proceeded to verify the functional feasibility of the fuel production in order to feed incinerators and power plants in partial or total substitution of the conventional fuels (coal, fuel oil)
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