6 research outputs found
On the exploitation of dynamic simulations for the design of buildings energy systems
No full textTo achieve the Paris Agreement 1.5 °C target, apart from the obligation for new buildings to be ZEBs, the existing building stock should be retrofitted as well, in order to improve their energy efficiency by using more efficient electromechanical energy systems and envelope materials, whereas RES should cover their energy needs. In this context, Energy Performance Certificates (EPCs) have been institutionalized to certify the energy behavior of buildings. Various types of buildings energy modeling tools and calculation methods have been proposed for EPCs procedures. This study focuses on the energy performance gap between dynamic and quasi steady-state simulation tools. The results from a comparative case study have shown remarkable discrepancies between dynamic and quasi-steady-state simulation processes, for the same building. Indeed, the quasi-steady-state simulation tool estimates 4.5% higher annual electricity consumption per conditioned area for the existing building and approximately 74% less energy savings for the retrofitted one, leading to an overestimation of 85% in CO2 emissions prediction. Finally, compared to the analysis with the dynamic simulation tool, an increased retrofit cost, approximately by 19.7% (and thus 3 times higher payback period), is needed according to the results of the quasi-steady-state simulation tool, in order to achieve the same Energy classification
Enhanced nZEB concept incorporating a sustainable Grid Support Scheme
No full textThe building sector in Europe represents a large amount of the total energy consumption. European Union policies urge energy management systems installation in buildings, to achieve the nZEB targets and mitigate the climate change. Except for renewable energy sources, the incorporation of energy storage units (ESUs) is of major importance for building energy management, in order to increase self-consumption levels. The present work contributes to the mass installation of ESUs in building sector, as a tool to provide flexibility in the distributed production of energy. This concept is an enhanced version of nZEBs that is able to compete in the Electricity Market, and to contribute to the reliability and flexibility of the electricity grid as an alternative to centralized ESUs investments. In this context, the present work proposes a new type of grid ancillary services for building sector and a novel Grid Support Scheme (GSS) that considers both the energy fluctuations of the available energy in the ESU as well as the energy transactions with the grid. The proposed GSS model concludes to a pricing policy relying on the Value of Lost Load (VoLL), in order that the proposed grid support investment becomes sustainable. The validation of the GSS is performed by means of Life Cycle Cost Assessment
Energy yield estimation of on-vehicle photovoltaic systems in urban environments
No full textGreenhouse gases from the propulsion systems of road transportations constitute a significant obstacle to achieve the Paris Agreement objectives. Nowadays, the substitution of conventional internal combustion engines with electric motors, along with electrochemical storage systems are the leading efforts to reduce the use of fossil fuels in road transportations. However, their limited driving range and the long charging times are the main technical factors that hinder the development of electromobility. Thus, energy harvesters and regeneration systems are increasingly incorporated in road vehicles, in order to increase their driving range. In this context, Vehicle Integrated and Applied Photovoltaics (VIAPVs) constitute an attractive prospect. The electricity yield for VIAPVs depends strongly on the route, the shadings due to the urban environment, the applied Maximum Power Point (MPPT) algorithm and the traffic conditions. In this paper, four commonly used commercial MPPT algorithms are experimentally evaluated, regarding their ability to extract the maximum available power simulating realistic city routes. The results show notable discrepancies in the performance of the studied algorithms, between terrestrial and VIAPV applications, highlighting the impact of poor MPPT performance in terms of power generation in moving vehicles
Evolution of PV systems in Greece and review of applicable solutions for higher penetration levels
No full textThe European Directive regarding the promotion of energy from renewable sources (Directive 2009/28 EC) specifies separate national targets for each member state of the EU community, in order at least 20% of EU total energy demands to be met by renewable energy sources by 2020. The analysis performed in this work highlights that grid connected photovoltaic (PV) systems bring remarkable energy benefits to the electricity supply of Greece, meeting in parallel its national targets. This is validated with data reported from the operator of Hellenic Electricity Market (LAGIE). On the other hand a mass energy production coming from PV systems without energy storage units and sufficient electricity network architectures is liable to cause severe disturbances to the Greek electricity network. This issue is acknowledged by representative data from the Hellenic Electricity Power Transmission and Distribution Network Operators (ADMIE and HEDNO). Furthermore, sustainable and innovative electricity network architectures (such as micro-grids, smart-grids and web of cells), as well as innovative intermittent Renewable Energy Sources (RES) stabilization techniques are discussed, in order to facilitate high PVs integration level
Households with Fibre Reinforced Composite BIPV modules in Southern Europe under Net Metering Scheme
No full textIn recent years many Renewable Energy Sources (RES) power plants have been connected to power networks throughout Europe, in order to meet the EU's objectives for sustainable energy supply. As far as RES residential applications are concerned, the grid-connected photovoltaic (PV) systems constitute the most important representative of RES, because PVs can be easily installed even in densely built-up areas. In this context, small residential PV systems utilising Building Integrated PV (BIPV) modules are going to gain ground mainly at newly built or rebuilt building structures. That is because a BIPV module operates as a multi-functional building construction material; it generates energy and serves as part of the building envelope. This paper highlights the energy benefits of residential buildings in Southern Europe with Fibre Reinforced Composite BIPV modules under Net Metering Scheme and proposes suitable grid-connected PV inverter structures in case of BIPV systems with multiple orientation and inclination profiles
The Role of Non-Human Creation in the Liturgical Feasts of the Eastern Orthodox Tradition: Towards an Orthodox Ecological Theology
No full textThis thesis examines the role played by non-human creation in the liturgies for the feast of Holy Pascha (Easter), of the twelve major feasts of the Orthodox Church, and of the period of Great Lent. Applying to liturgical texts and practices the methodology developed by Paul Ricoeur for biblical interpretation, the thesis argues that the kind of world opened by these liturgies allows for the participation of non-human creatures in the liturgy and thus is amenable to an ecological theology. It investigates the implications of the liturgical texts for contemporary theological reflection about salvation, incarnation, sin, and theosis in light of the ecological crisis and the frequent Orthodox claim that the liturgy is ‘cosmic’ in scope. Chapter 1 looks at the role of non-human creation in the Paschal/Pentecost season and lays out the case for the need to include all of creation. Chapter 2 focuses on the feasts of the incarnation and argues for a more inclusive theological interpretation of the incarnation. Chapter 3 examines the liturgies of Lent and Holy Week and develops hamartiological implications of the ecological crisis. The final chapter focuses on the feasts of Theophany and the Transfiguration and proposes a view of theosis that extends beyond humans
