1,720,985 research outputs found
The role of demand side management into the emergency department: a smart health grid solution
No full textParametric Exergy Analysis of a Tubular Solid Oxide Fuel Cell (SOFC) stack through Finite-Volume Model
No full textA joint approach for strategic bidding of a microgrid in energy and spinning reserve markets
Full text linkIn the electricity market, short-term operation is organized in day-ahead and real-time stages. The two stages that are performed in different time intervals have reciprocal effects on each other. The paper shows the strategy of a microgrid that participates to both day-ahead energy and spinning reserve market. It is supposed that microgrid is managed by a prosumer, a decision maker who manages distributed energy sources, storage units, Information and Communication Technologies (ICT) elements, and loads involved in the grid. The strategy is formulated considering that all decisions about the amount of power to sell in both markets and the price links to the offer, must be taken contextually and at the same time, that is through a joint approach. In order to develop an optimal bidding strategy for energy markets, prosumer implements a nonlinear mixed integer optimization model: in this way, by aggregating and coordinating various distributed energy sources, including renewable energy sources, micro-turbines–electricity power plants, combined heat and power plants, heat production plants (boilers), and energy storage systems, prosumer is able to optimally allocate the capacities for energy and spinning reserve market and maximize its revenues from different markets. Moreover, it is considered that both generators and loads can take part in the reserve market. The demand participation happens through both shiftable and curtailable loads. Case studies based on microgrid with various distributed energy sources demonstrate the market behavior of the prosumer using the proposed bidding model
Parametric exergy analysis of a tubular Solid Oxide Fuel Cell (SOFC) stack through finite-volume model
No full textThis paper presents a very detailed local exergy analysis of a tubular Solid Oxide Fuel Cell (SOFC) stack. In particular, a complete parametric analysis has been carried out, in order to assess the effects of the synthesis/design parameters on the local irreversibilities in the components of the stack. A finite-volume axial-symmetric model of the tubular internal reforming Solid Oxide Fuel Cell stack under investigation has been used. The stack consists of: SOFC tubes, tube-in-tube pre-reformer and tube and shell catalytic burner. The model takes into account the effects of heat/mass transfer and chemical/electrochemical reactions. The model allows one to predict the performance of a SOFC stack once a series of design and operative parameters are fixed, but also to investigate the source and localization of inefficiency. To this scope, an exergy analysis was implemented. The SOFC tube, the pre-reformer and the catalytic burner are discretized along their longitudinal axes. Detailed models of the kinetics of the reforming, catalytic combustion and electrochemical reactions are implemented. Pressure drops, convection heat transfer and overvoltages are calculated on the basis of the work previously developed by the authors. The heat transfer model includes the contribution of thermal radiation, so improving the models previously used by the authors. Radiative heat transfer is calculated on the basis of the slice-to-slice configuration factors and corresponding radiosities. On the basis of this thermochemical model, an exergy analysis has been carried out, in order to localize the sources and the magnitude of irreversibilities along the components of the stack. In addition, the main synthesis/design variables were varied in order to assess their effect on the exergy destruction within the component to which the parameter directly refers ("endogenous" contribution) and on the exergy destruction of all remaining components ("exogenous" contribution). Then, this analysis is used to detect the parameters to be optimized in order to reduce the overall irreversibility rate in the cell
The role of protection systems in Smart Grids: the Protection Automation and Control application
No full textThis paper provides an overview on Protection, Automation and Control systems at Smart Grids. The aim is to analyze the state of art, challenges and barriers that protection system must deal with in the advent of new smart power system. Smart Grids implementation requests more coordination between the several resources involved in the network than the traditional power systems, more control in order to guarantee always the good work of the grid, and a faster communication system. In this context the role of the Protection, Automation and Control system is crucial, Protection, Automation and Control systems must be able to work both in normal condition and to protect against the unexpected situation. A solution for the protection issue is represented by the several schemes that can be applied to the Smart Grid, and that will be described in this work. Finally, an advanced Protection, Automation and Control system designed and currently in development at ENEA Smart Grid and Energy Network laboratory is shown
Analisi energetica, economica ed ambientale di un impianto di trattamento del percolato da discarica
No full textA smart health grid solution for demand management of Emergency Departments
No full textOvercrowding is a very challenging problem that Emergency Departments (EDs) face every day.
Many scholars dealt with it focusing on a single ED and few works analyse the problem in a
network perspective. In this paper, we reinforce the idea that managing EDs as a network can be an
appropriate solution for mitigating overcrowding. Based on energy smart grid concept, we propose
an optimization model of demand side management for reducing the waiting time of the ED
network. In order to show the potential of model, its application to a 3 EDS network located in
Naples (Italy) is presented
What drives university engineering students to become entrepreneurs? Finding different recipes using a configuration approach
No full textThis research aims to investigate how combinations of factors lead to the entrepreneurial intention and propensity of engineering university students. The study proposes the application of a configuration approach (Qualitative Comparative Analysis) with a sample of 10,008 engineering students from 43 universities in 10 European countries. The findings show that entrepreneurial intention and propensity do not depend only on a single driver but on the interplay of multiple factors. The intensity of entrepreneurship education is a necessary but not sufficient condition. Different recipes brought to light in the analysis belong to similar socioeconomic contexts
Mapping of Energy Community Development in Europe: State of the Art and Research Directions
Full text linkWithin the framework of defining a new energy paradigm to address climate change and other global challenges, the energy community model is gaining interest in several countries, especially in Europe. This article analyses the literature and experiences of organisational forms that fall under the definition of energy communities in a broad sense, in relation to their ability to bring improvements to the social, environmental and economic dimensions, and to ensure durability and replicability. The main elements that constitute a complete, albeit simplified, model of energy community are identified and analysed. The legislative and regulatory frameworks, technologies and social innovation frameworks, identified here as enabling elements, are discussed, as well as the elements of the energy community business models and the impacts generated at the environmental and energy, economic and social levels. The transformation potential of energy communities is confirmed as more than promising. However, in order to develop as a sustainable and replicable model capable of achieving social and environmental goals, as well as economic stability, further significant research and experimentation, following a cross-sectoral and multidisciplinary approach and strong political leadership, are needed
- …
