1,720,984 research outputs found
Solar-powered cooling systems: Technical and economic analysis on industrial refrigeration and air-conditioning applications
No full textIn the last years, the growing demand for air conditioning has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the technologies which allows to obtain, by using the renewable solar source, an important energy saving compared to traditional air conditioning plants. The paper describes different technical installations for solar cooling, their way of operation, advantages and limits. The objective of the present study has been to analyze the technical and economic feasibility of solar absorption cooling systems, designed for two different application fields: industrial refrigeration and air conditioning. The possibility to replace or integrate the existing plants is studied, by considering the refrigeration requirements of a company, which works in meat manufacturing, and the heating and cooling demands of a hotel located in a tourist town in Italy. In the first case, the system comprises an absorption chiller coupled to solar flat plate collectors, whereas the second application is about a hybrid trigeneration plant, known as thermo-solar trigeneration; this option allows having greater operational flexibility at sites with demand for energy in the form of heating as well as cooling, for example in a hotel. In this way the authors could compare different results obtained by a technical and economic experimental analysis based on existing users and evaluate the advantages and disadvantages in order to suggest the best solution for the two studied cases
Life cycle assessment of a reflective foil material and comparison with other solutions for thermal insulation of buildings
No full textIn the last twenty years, the exploitation of non-renewable resources and the effects of their applications on environment and human health were considered central topics in political and scientific debate on European and worldwide scale. This kind of resources have been used in different sectors, as energy systems, technological research, but also in private/public buildings and production of consumer goods, involving significantly domestic and ordinary life of every human being. Studies about the effect of this exploitation carried out discouraging results, in terms of climate changes and energy sustenance; this determined a progressive approach process to a new concept of development, able to couple the qualitative standard of modern life with the respect of planet and its inhabitants. Starting from this reflection, scientific community moved towards research on alternative resources and developed a new way to conceive planning process and technical innovations, in order to exploit renewable energies and recycled materials, promote energy savings and reduce environmental pollution. In this context the present paper aims at evaluating benefits relating to different solutions of thermal insulation in building envelope. In fact a high grade of insulation ensures better comfort conditions in inner spaces, reducing energy consumptions due to heating and cooling conditioning. The paper presents the results of a detailed Life Cycle Assessment (LCA) of the reflective foil ISOLIVING, conceived and produced by an Italian company. The Life Cycle Assessment methodology allows to consider all stages of the life cycle, from the extraction of raw materials to the product’s disposal, in an optics “from cradle to grave.” In particular, the study takes into account the production phase of the reflective foil ISOLIVING, the installation phase, the transport of all components to the production site and also the end of life scenario of the material. The possibility to collect many detailed information about the production phase adds value to the study. The analysis is carried out according to UNI EN ISO 14040 and UNI EN ISO 14044, which regulate the LCA procedure. The LCA modeling was performed using SimaPro software application. The results of the analysis allow to make an important comparison concerning the environmental performances, between the reflective foil ISOLIVING and other types of insulating materials
An energy saving solution applied to the final use of electrical and lighting systems of school buildings managed by Perugia Province
Full text linkIn this paper, a study and design of energy conservation actions and the obtention of Energy Efficiency Titles, according to the Italian Ministerial Decree 20th July 2004, applied to lighting and electrical systems in a school district managed by Perugia Province (Italy), is presented. Specifically, the analysis regarded the replacement of neon lamps with high efficiency ones, and the power factor correction of the electrical system with a lower value. The work was carried out through an energy audit of some school buildings. From the results of this energy audit, project solutions were developed and a technical and economical feasibility study was made. This study was then extended to the whole school building fleet managed by Perugia Province. The results of this work were validated by a commercial feasibility assessment through an ESCo
Progetto e realizzazione di una casa passiva a Perugia: bilancio energetico e simulazione per la scelta di soluzioni impiantistiche ottimali
No full textAnalysis of pollutant emissions from cogeneration and district heating systems aimed to a feasibility study of MCFC technology for carbon dioxide separation as retrofitting of existing plants
No full textThe growing world consumption of energy from fossil fuels has the side effect of increasing emissions of greenhouse gases and other pollutants, causing damage respectively at global and local levels. The combination of high temperature fuel cells with traditional energy production systems seems to be one of the possible solutions to this environmental problem. In this context, molten carbonate fuel cells (MCFCs) are the only fuel cells which may work as CO(2) concentrators/separators, if fed by the exhaust gases of a power plant. This paper investigates the chemical composition of flue gases from existing cogeneration plants, in order to perform a feasibility study of the MCFC technology for CO(2) separation. For this purpose, a model of a MCFC using as input the exhaust gas of a combined heat and power plant has been developed and analyzed. The aim of the whole study is to identify the optimal operating conditions of the cell, to achieve the maximum CO(2) removal efficiency
Integrated Planning of a Multifunctional Complex in Perugia: Sustainable Building Solutions and Energy-Environmental Certification
No full textThe need and desire to achieve sustainable architectures, including control of energy relations between climate and built environment to optimize energy consumptions and reduction of environmental impact, require an integrated planning dealt with a multiscale and integral view of building-plant system. In this paper the case of multifunctional building complex Solaria is described: a redevelopment project of a disused industrial area, approximately 20,000 m2, located in the center of Ponte San Giovanni, a town in the immediate periphery of Perugia (Italy), conceived and designed in accordance with the logic above mentioned. Objective of the study has been to achieve an integrated approach to the problems related to demands of comfort and healthy living, sustainability of building process, containment of energy consumptions and use of renewable energy resources. The coordination for energy efficiency has supported an accurate study of plant-structural interventions and innovative experimental components, which synergistically integrated in a single project have enabled to reach important results, as demonstrated by the assessment of avoided CO2 emissions, equal to nearly 500 tons per year. The project plans, for instance, to provide the building complex with: a high-efficiency tri-generation plant (525 kW of electric power) coupled with a distribution network for district heating/cooling; a photovoltaic generation system with 20 kW of peak power and solar thermal panels for sanitary warm water production, able to supply over 50% of the needs; passive solar systems (solar greenhouses and "heat cushions"), equipped with sliding brise-soleils. Moreover, the results are certified through energy certification and sustainability valuation, in accordance with the building code of Municipality of Perugia, and through the BESTClass certification methodology promoted by SACERT. The process for reaching better energy efficiency class has been analyzed under environmental and economic profiles, in terms of avoided emissions and higher costs compared to a standard design. The realization of energy efficiency solutions designed for Solaria makes the complex an advanced model, but also repeatable, of integrated planning unique in the regional scene, as well as a practical application of European Directives on the energy performance of buildings (2002/91/EC) and on energy end-use efficiency and energy services (2006/32/EC)
Comparative Analysis of Three Methodologies for the Energy Certification Applied to Residential Buildings, Developed in Italy in Conformity with European Directive EPBD 2002/91
No full textIn this paper different methods for energy building certification are analyzed in order to examine their application to a residential building into a new multi-functional building complex in Italy. In accordance with Italian and European standards, the authors evaluated the most representative apartment of the residential complex in order to certify all the other lodgings. Currently in Italy there are no existing national guidelines to certify energy performance of buildings, so the case study was evaluated by three different methodologies developed in Italy: CLASS, developed from the Province of Milan and B.E.S.T. Department of the Milan Polytechnic with the technical contribution of ANIT (National Association for the Thermal and acoustic Isolation), the methodology adopted in its own building code by the City of Perugia based on the standard of ITACA Protocol, and finally the CEIP® method elaborated by the Department of Industrial Engineering of the Perugia University. In this way the authors could compare different results obtained by three different methods and evaluate the advantages and disadvantages in order to suggest a better procedure mixing the best of each one. The research is elaborated with the background of the Italian law Digs 192/05, that aligns Italy with the European Directive EPBD 2002/91/CE. However, the legislator has not yet issued the decrees which make it operative
Analysis of Emissions into Atmosphere of the Cogeneration and District Heating Plant in Norcia (Italy)
No full textDistrict heating enables to recover heat produced simultaneously with electricity in combined heat and power generation plants, which would be wasted and dissipated into environment, in order to supply residential and commercial heating requirements; the distribution of this energy is realized close to production site, minimizing losses associated with transportion. The European-wide Authorities identify in urban district heating systems a great opportunity for rationalizing energy use and a very interesting way to decrease harmful emissions, in order to reduce local pollution as well as greenhouse gas emissions. In this paper the district heating plant built in Norcia (Perugia, Italy) is described: it is located in the area of Sibillini, a mountain range that divides anche and Umbria regions, in the centre of Italy. The system is powered by a natural gas cogeneration plant characterized by three engines for an overall electric power of 1050 kW and a thermal power of 1500 kW. The plant supplies heat to about forty industrial and civil users Objective of this study is to correlate the data recordered by monitoring emissions of cogeneration system following several load profiles, in order to optimize simultaneously system management and the trend in emissions into atmosphere. Different emissions are processed through a flue gas analyzer, installed permanently at the poer generator, able to monitor real-time (range of programmable recording from 250ms) concentration of CO, NOx, CO2 and the temperature of the flue gases. Data recording has enabled to compare current situation with the pre-existing one, before plant's realization, in terms of air quality
Feasibility study and design of a low-energy residential unit in Sagarmatha park for environmental impact reduction of high altitude buildings
Full text linkThe project presented in this paper is geographically set within Sagarmatha National Park, a wide area located on the Nepalese mountainside of Everest and declared as World Heritage Site since 1979. In recent years the park was the focus of several studies and initiatives, aimed at improving the management of its many-sided ecosystem, significantly influenced by climate change and increase of human activities and tourism, which occurred from the end of the 1970s, as well as by practices that are harmful both to human health and to our environment (e.g. burn up kerosene or animal excrements in order to obtain heat). Research work has focused on designing a residential unit that meets population needs, in terms of simplicity of realization, replicability, use of local materials, environmental compatibility and exploitation of available renewable energies. For this purpose a thorough analysis was conducted to identify the housing standard characteristic of reference context and Sherpa people, concerning indoor thermal comfort conditions, construction techniques, availability and skills of local workforce. Data necessary for the design phase were obtained through a collaboration with researchers of Ev-K2-CNR center, active at 5,050 meters a.s.l. in Nepal at the base of Mount Everest with a laboratory/observatory (known as the "Pyramid") for highaltitude meteorological studies since 1989. Climate conditions were registered by specific monitoring stations at certain times (2002-2008); during preliminary stage, these values were considered representative of the local context chosen for the project, that is Namche Bazar, a village located within the park, in a central point both from the logistic and altimetric/weather points of view. For the residential unit under investigation, two different constructive approaches were selected and compared: earthbags and straw bales. Both techniques have several advantages, in particular availability of raw material (jute bags, soil, straw), simplicity (e.g. earthbag constructions are realized using the ancient technique of pisé, combined with flexible bags or tubes), durability, insulation performance, costeffectiveness. Through a specific software for calculation of winter/summer thermal loads, different combinations of selections of structure and insulation were examined for both solutions, in order to achieve the optimum for the case study. Furthermore on the base of data monitored on site, a specific assessment was carried out to evaluate the potential of solar and wind resources. Aiming at entirely covering the heat and electric energy needs by exploiting renewable energy sources, various plant configurations were finally assumed. Every single choice was made to reduce human influence on land resources, such as timber, and to improve internal and external environmental quality
Exploring the academic landscape of energy communities in Europe: A systematic literature review
Full text linkOver the past few years, energy communities initiatives have gained traction in Europe as a means to achieve energy transition goals, allowing citizen involvement in energy production, consumption, and distribution. Following the 2018 European directive RED II, these projects have rapidly increased across the continent, showcasing their potential for creating sustainable local energy systems. While studies highlight economic, environmental, and social benefits, barriers such as regulatory challenges, finance access, and low public awareness remain. This paper presents the results of a systematic literature review that explores the state-of-the-art of the academic research on energy communities. The study adopts a systematic approach to examine the body of literature on the topic to provide a comprehensive analysis of the phenomenon on the basis of rigorous and replicable research criteria. The reviewed material consists of 140 articles collected through the Scopus database, evaluated using specific structural dimensions to group the literature into analytical categories. The analysis of scientific papers published between 2018-2022 shows a growing attention towards Renewable Energy Communities, particularly those based on solar energy for electricity production, often combined with storage systems and heat pumps, whereas attention towards energy communities based on thermal energy production is still limited. Furthermore, most scholars focused on analysing specific territorial contexts; comparisons between different regions allows to highlight common features and elements characterizing each model. It emerged that the development of energy communities depends mainly on regulatory, financial, and managerial barriers that require an adequate institutional and legal framework capable of promoting their diffusion. Most studies address the topic from an economic perspective, often in association with incentivizing community models. However, a social perspective should be included by introducing the concept of energy sharing and methodologies for its distribution among all members of the community. The scientific community is called upon to continue investigating and supporting the development of community energy initiatives by providing evidence-based recommendations to policymakers, industry stakeholders, and local communities. This can help to overcome existing barriers and facilitate the diffusion of energy communities models, contributing to the achievement of sustainable and inclusive energy transition goals
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