1,720,962 research outputs found
A fair dynamic incentive allocation method for virtual energy sharing in renewable energy communities that rewards members’ virtuosity and engagement
Full text linkThe development of renewable energy communities is essential for the energy transition and is strongly supported by European policies promoting local renewable energy initiatives. However, implementing fair economic allocation methods remains a significant challenge, as these must maximize the benefits of local renewable generation and encourage efficient electricity sharing. Addressing this issue is necessary for advancing the effectiveness and equity of renewable energy communities across Europe. This work proposes a novel economic incentive model aiming to equitably allocates rewards among users in electricity-sharing initiatives. The method uses a reward system based on daily evaluations of two factors: a similarity factor, measuring each user's alignment with renewable generation profiles, and a utilization factor, assessing the renewable energy exploited to meet their load. A case study of four members in a standard Italian multifamily residential building demonstrates the model's effectiveness. Results show that users' virtuous behaviours positively impact energy efficiency and economic returns. The findings highlight this method's potential to enhance community engagement, foster cooperation, and drive renewable energy adoption. This study provides a robust framework integrating economic principles with renewable energy use, showcasing the viability of innovative incentive mechanisms to promote equitable, sustainable energy practices and support the global energy transition
A framework for assessing the energy performance of Personalized Environmental Control Systems (PECS) for heating, cooling and ventilation
Full text linkThis study presents a methodological framework for assessing the energy performance of Personal Environmental Control Systems (PECS), aiming to address the existing gaps in standardized evaluation approaches. Initially, a systematic approach to delineate the distinct spatial control volumes associated with PECS is presented, facilitating the classification and comparison of various system types. Utilizing this framework, the study introduces definitions for energy efficiency and effectiveness specific to PECS, providing a procedure for the experimental assessment of the quantities related to these definitions. To validate the proposed framework, the method was applied to an illustrative case study involving two PECS under varying operational conditions – heating and cooling. The experimental results provide insights into the energy performance of the evaluated PECS, highlighting the framework's applicability and effectiveness in assessing their energy efficiency. The study underscores the importance of systematically evaluating PECS energy performance, offering a robust methodology that can guide future research and development efforts in this domain
La contabilità a base economico patrimoniale
No full textL'obiettivo del capitolo è spiegare come e perché si tiene la contabilità economico-patrimoniale degli enti territoriali: Regionali ed enti locali. Il percorso logico-didattico seguito nel capitolo è guidato dal principio di non disgiungere mai la soluzione tecnica da adottare dalla sua spiegazione. Il capitolo affronta i tre momenti tipici delle rilevazioni in contabilità economico-patrimoniale: le scritture continuative, le scritture di assestamento economico e le scritture di chiusura e riapertura
Modelling a fifth-generation bidirectional low temperature district heating and cooling (5GDHC) network for nearly Zero Energy District (nZED)
Full text linkCurrent sustainability challenges place entire communities at the centre of the energy revolution, rather than individual buildings. The need to develop energy-efficient and low-carbon economies lies at the heart of fifth-generation district heating and cooling (5GDHC) networks. The potential of these networks is represented by a lower working temperature close to the ground temperature, usually between 10 and 25 °C. Thanks to this feature, the network presents optimal conditions to be used as a heat source for reversible heat pumps. 5GDHC networks provide users with a fundamental active role, giving the possibility of extracting and releasing energy into the thermal network, while producing heating and cooling simultaneously. The integration of renewable sources and reduced heat losses are added values to be taken into consideration. Given the limited application of 5GDHC networks, this paper aims to evaluate the energy advantages of coupling several users within a bidirectional fifth-generation network based on the integration of reversible heat pumps with on-site production by renewable sources and waste energy recovery. An integrated model of 5GDHC network with buildings was developed in order to meet the energy needs of a neighbourhood made up of users with different energy profiles throughout a whole year. To enhance future applications, the energy performance of the 5GDHC network model was studied through a simulation tool. An hourly numerical calculation tool was developed to simulate the behaviour of the network and the users’ response over an annual period, estimating the energy shared between users during both the heating and cooling seasons. The results obtained are presented not only in terms of energy exchanged in the network, but also in the form of performance indexes of the individual users, identifying advantageous combinations between the users for future design developments of these systems. The outcomes of this paper highlight the integration of established technologies into fifth-generation thermal networks, with a view to a future development of nearly Zero Energy Districts (nZED)
Design and experimental analysis of an Integral Collector Storage (ICS) prototype for DHW production
Full text linkThis paper presents an innovative solar ICS (Integral Collector Storage) for the production of Domestic Hot Water (DHW). The novelty consists in combining an absorbent surface, heat pipes and a storage cavity made up of a phase change material (PCM) within a single compact casing. The energy performance of the system was experimentally studied in different seasons of the year, with and without domestic hot water production. The temperatures inside the collector were monitored using K-type thermocouples and their trends were analysed and discussed. During the experimental phase, the thermal storage reached the maximum temperature of 79.3 °C, exploiting the latent heat of the PCM. Overall performances demonstrated good agreement with results available in the literature in terms of efficiency and energy storage. A specific heat flux of 2.64 kW·m−2 was achieved in DHW production, with a water flowrate of 0.87 kg·min−1. The 0.02 m3 PCM section was able to store 24.57 kWh of thermal energy along a monitored month. Future developments of this new technology include new experimental tests with larger prototypes and the coupling with a real user
Static vs dynamic hygrothermal simulation for cellulose-based insulation in existing walls: A case study comparison
Full text linkWhen dealing with energy-saving topics, it is increasingly common to focus on the efficiency of existing systems, rather than adopting new ones. In the specific case of the building envelope this practice is supported by the difficulty in completely replacing opaque components of the envelope, such as external walls or roofs. This work involves the renovation of a cavity wall, with the aim of improving its energy performance. A traditional cavity wall has been modified by blowing a bio-based insulating material obtained from cellulose flakes inside the air cavity gap. Although an operation of this type leads to a significant increase in thermal performance of the wall, it is not equally obvious that it is effective in terms of humidity and vapor condensation. The purpose of this work is to evaluate the effect of the blowing process on the hygrometric performance of the opaque component to ensure correct compliance with the performance parameters established by Italian legislation in terms of vapor transmission and condensation phenomena. In order to study the hygrometric behaviour, a numerical model of the construction was developed and simulated. The simulation involved two different regulatory approaches, which were compared: a first calculation was carried out in steady-state conditions, according to the UNI EN ISO 13788 standard (ISO, 2012). Afterwards, a dynamic simulation following the UNI EN 15026 standard was performed (CEN, 2007). The results obtained by both the methods were analysed and compared. The results demonstrate that by adopting the calculation procedure in steady-state conditions, the phenomenon of interstitial condensation occurs. A different result is obtained by applying the calculation method in dynamic regime, according to which the vapor would not condense inside the structure
Resilient optimal design of multi-family buildings in future climate scenarios
No full textIn Europe, the second recast of EPBD promotes long-term strategies to accelerate the path to nZEBs, fostering the cost-optimized building design already suggested in the EPBD first recast. Since the nZEB design is a complex optimization problem that is subjected to uncertainty in its boundary conditions (climate, technologies, market, ...), it is necessary to guarantee the resilience of the NZEB optimal design to possible variations of future scenarios, especially as regards the climate change. This work applies the new EdeSSOpt methodology (Energy Demand and Supply Simultaneous Optimization) developed by the Authors aiming at investigating the variation of the cost-optimized multi-family building design in different Italian future climate scenarios, therefore considering parameters related to the building envelope, energy systems and renewable energy sources. The method is implemented into the TRNSYS® (energy model), GenOpt (optimizer) and WeatherShift® (future climate scenario generator) tools. The resulting cost-optimal solutions in future scenarios are related to a lower global cost and a decreased total primary energy consumption. Beyond the future trends of such performance indexes, the fact that most of technical solutions associated with the optimal solutions have not changed with the studied climate scenarios, indicates a certain resilience of the optimal design variables facing climate change
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
