1,720,998 research outputs found
Weights of embodied energy and carbon emissions in an energy retrofit of the building envelope: Assessment for a Mediterranean residential building
No full textEurope’s commitment to reduce energy consumption and CO2 emissions by 2050 led to a proposal to amend the EPBD in December 2021. This proposal introduces the environmental footprint assessment for new buildings involving all phases of their life cycle. The life cycle approach, however, could provide valid suggestions and results even if applied to energy renovation interventions. In this study, the LCA methodology - according to the variant cradle-to-gate with options - is used to investigate the energy and emissions consumed and produced for the energy-oriented retrofit of both opaque and transparent building envelope of a residential building, in the Mediterranean area. The analysis shows that the solutions that allow maximum energy savings in the operational phase of the building differ from those characterized by minimal energy impact from a life cycle perspective. At the same time, however, the latter enable an acceptable operational energy saving and a higher total reduction of energy demands. In detail, the solution that allows maximum energy savings in the operational phase, equal to about 39.4%, has a weight of the embedded energy of 7.1%. The solution with the minimum weight of the incorporated energy, equal to about 5.5%, allows an operating energy saving of 39.1%
H2 micro-cogeneration in buildings: from nZEBs to HZEBs. State of Art, with a novel experimental set-up
No full textA new installation of hydrogen FC in a net zero energy building is presented, to support the energy transition toward clean energy systems. The development of hydrogen technologies, both for the high electrical efficiency of small sizes and for the energy storage potential (in the presence of electricity surplus from renewables) may have an important potential for a low carbon future. Surely, with a view to renewable energy communities, the scientific research on storage - thermal and electrical, daily and seasonal - is becoming central to compensate for the temporal "gaps" between conversion and use of energy. These topics are here discussed, presenting a novel installation of H 2 in a real living lab building, an example of the transition from nZEBs to HZEBs. In particular, wide in-field monitoring is under investigation, by testing the real performance of a small-scale solid oxide fuel cell, in which both electrical and thermal output are used to cover the low energy demands. The technology is highly promising, being improved electrical efficiency with respect to other CHP technologies, and this fulfills the future energy transition, which will be characterized by an equal or increased demand for electrical energy, with a lower need for heat
From consumers to prosumers: the rise of Energy Communities and their role in the energy transition
No full textThis paper provides an overview of energy communities, analyzing the energy context, with environmental and climate problems, that have led to the need to develop smart and sustainable solutions for a new social model of energy self-production. The concept of energy community contains important objectives for the sustainable evolution of cities, firstly the spread of renewable energy. Exploring the methodologies and approaches used in the literature, conclusions were drawn to be able to manage and understand the functioning of zero-impact energy systems, defined as nearly-zero energy districts, where energy is designed to be shared. To overcome the boundaries of the individual building and consider the influence of the surrounding urban context, starting from the concept of a smart city and the limits of the model itself, the importance of having an overview of the urban area is defined, and citizens themselves to cooperate in the design and management of energy systems and energy production, thus considering the concept of selection of energy flows. By defining the concept of the energy community, the state of the art in Europe is explained, by analyzing real cases and classifying them according to technical characteristics, types of modeling/optimization approach and methodology used to assess the performance of the energy community. The final aim is to show the potential advantage, through the evaluation of the reviewed articles, to use the redevelopment of an ex-industrial area such as Bagnoli (Naples, Italy) to make it a renewable and sustainable energy community. © 2023 University of Split, FESB
Social housing as an open issue of energy consumption in the building sector in Europe: a case study in Berlin
No full textThe decarbonization goal by 2050, as set by Directive 844/2018, is an ambitious objective that requires a big effort. The strategy to act on the building sector includes the construction of new highly efficient buildings and the energy refurbishment of the existing ones. This study focuses on the renovation of social housing buildings, which are a wide component of the existing building stock, and in most cases, present poor energy performances. The investigation focuses on the role that social housing plays in the European building stock, from an energy point of view, and through significant examples, review the strategies adopted to improve their energy performances. A significant case study in Berlin, representative of both German and even European social housing, was investigated by selecting energy efficiency measures to improve its performance. In a final configuration that combines different energy efficiency measures, a heating thermal energy saving of 88% was obtained. The study includes a technical economic analysis of the proposed energy efficiency interventions and shows how some of them are not economically convenient without governmental incentives
Using Miniature Thermoelectric Generators for Wearable Energy Harvesting
No full textUsing thermal energy harvesting from human body has the potential to create wearable self-powered devices for multitude of purposes. The focus of this work is to develop a flexible thermoelectric module prototype, consisting of 8 encapsulated miniature thermoelectric generators, which can later be used for powering such a device. The first part of the work focuses on measuring electrical parameters of single miniature thermoelectric generators and the power output of the whole module while using various series-parallel configurations. In the second part of the work a measurement on the forearm is performed to measure typical power output of these configurations in room temperature. Average power output at rest is 3 μW. The last part of this work is centered around testing two DC/DC step-up converters, the LTC3108 and EM8900. Only the EM8900 is proven effective at powering an analog accelerometer with the proposed thermoelectric module as the only power source
Optimization of solar energy exploitation for a neighborhood towards nearly zero energy buildings
No full textThe energy transition of neighborhoods towards nearly zero energy buildings (nZEBs) is fundamental to promote sustainability. The study deals with this issue by proposing a methodology to optimize energy retrofit through the exploitation of solar energy by photovoltaics. Part of a neighborhood in the city of Naples (South Italy) is investigated. The coupling between EnergyPlus and MATLAB® is used for energy modelling, simulations and retrofit optimization through a smart research method, performing a comprehensive analysis of heating, cooling and electric loads. A Pareto multi-objective approach is applied to minimize both energy consumption and global cost in order to optimize the solar energy exploitation and to achieve the nZEB standard while ensuring cost-effectiveness. Different retrofit scenarios for building envelopes and energy systems are investigated. Two optimal retrofit solutions are identified. One pursues the minimization of the neighborhood's energy impact ensuring a PEC reduction from 116.8 kWh/m2a to 66.3 kWh/m2a with discounted payback (DPB) of around 10 years. The other solution maximizes the cost-effectiveness yielding a PEC around 83.7 kWh/m2a with a DPB of only 4 years. The outcomes offer deep insights into the potentials of energy transition for neighborhoods and guidelines for the implementation of multi-generation energy systems as well as to address public energy policies
Comprehensive insights into the influence of climatic stress on building heating demand
No full textThe study aims at providing comprehensive insights into the influence of the climatic stress on building heating demand. The examined case studies are two residential buildings, representative of the Italian existing and newly-built stocks, respectively. Building energy performance is simulated by comparing a standard normative approach with a tailored accurate one using EnergyPlus. The comparison is performed for several locations (i.e., 63) to consider all typical Italian climates. A global sensitivity analysis is performed to identify the most influential climatic parameters and to investigate the correlation between heating demand and HDD (heating degree days). The findings show that a base temperature of 18 °C in HDD assessment provides higher determination coefficient compared to 20 °C, and that HDD should consider also solar radiation and/or latitude to achieve a better correlation. Finally, climatic stress curves are provided to assess thermal energy demand and running cost for heating operation as a function of HDD for both the existing and the newly-built building
A Microservices-based IoT Monitoring System to Improve the Safety in Public Building
No full textSafety of public buildings' users is an important issue, especially in buildings frequented by a great number of people. In such places, in case of an emergency, like a fire, rescue workers must intervene in a timely manner, directing their efforts towards places where there are people to be saved. This work presents an Internet of Things(IoT)-based framework, aiming at monitoring environmental parameters in order to support rescuers during emergencies. The microservices paradigm allows a pattern-based specification of system components that are refined and adapted on-The-fly depending on the specific execution context, based on the changing aspects such as, user's need and requirements, context variables, user's behavior, sensor data. First results related to the validation of the proposed system mainly concerning non-functional requirements of the implemented system through a proof-of-concept are reported and discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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