Browsing by Author "Silva, Carlos"
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- Conversão de edifícios existentes em nzeb através da integração de energias renováveis, de micro-redes e de soluções de eficiência energéticaPublication . Estanqueiro, Ana; Joyce, A; Aelenei, Laura Elena; Facão, Jorge; Rodrigues, Carlos; Loureiro, David; Teixeira, J.; Correia, J.B.; Ramalho, Álvaro; Camelo, Susana; Silva, Carlos; Neto, Rui C.RESUMO: O Projeto IMPROVEMENT “Integration of combined cooling, heating and power microgrids in zero-energy public buildings under high power quality and continuity of service requirements” é um projeto financiado pelo Programa INTERREG SUDOE, de cariz marcadamente multidisciplinar e que reúne competências da área de integração e modelação de sistemas energéticos, da gestão de energia em edifícios, de energias renováveis, micro-redes inteligentes e sistemas de monitorização e gestão de consumo. Tem ainda como objetivo geral renovar edifícios públicos existentes, convertendo-os em edifícios com necessidades de energia quase nulas (NZEB), e para tal integra micro-redes com fontes renováveis e geração combinada de calor, frio, eletricidade, equipadas com sistemas de armazenamento.
- Mapping flexibility of urban energy systems (FIRST) project: rationale and study design of an exploratory projectPublication . Aelenei, Daniel; Lopes, Rui Amaral; Silva, Carlos; Costa, F.; Majdalani, N.; Simões, Teresa; Goncalves, Helder; Aelenei, Laura ElenaABSTRACT: With the publication of the new Energy Performance of Buildings Directive, a large number of buildings are expected to become high energy performance and explore more the availability of renewable energy resources. Such buildings are often described in literature as nearly Zero-Energy Buildings (nZEB). Because renewable energy sources, such as wind and solar power, have an intrinsic variability, the zero-energy annual balance of nZEBs is difficult to reach at short time resolution (e.g. hourly). Thus, since electricity generation from small-scale solar renewable (typical case in Portugal) in individual households has limited capacity to be adjusted according to the power system needs, it is relevant to consider the demand flexibility potential, specially at community level (cluster of buildings). Unfortunately, there is a lack of studies on the impact of changes in electricity use at urban level on the future energy systems. Therefore, an approach addressing the energy flexibility (EF) in buildings may allow obtaining useful exploratory directions for the construction sector and related markets, policy makers and regulatory bodies. For these reasons, an exploratory project aimed at examining the potential of EF at the level of an existent neighbourhood in Lisbon was initiated. In this article we describe the objectives, design, and methods of the FIRST project, designed to map out the potential for EF in terms of benefits and costs in Lisbon.
- Performance assessment of a building integrated photovoltaic thermal system in Mediterranean climate : a numerical simulation approachPublication . Bot, Karol; Aelenei, Laura Elena; Gomes, Maria da Glória; Silva, CarlosABSTRACT: This study addresses the thermal and energy performance assessment of a Building Integrated Photovoltaic Thermal (BIPVT) system installed on the facade of a test room in Solar XXI, a Net Zero Energy Building (NZEB) located in Lisbon, Portugal. A numerical analysis using the dynamic simulation tool EnergyPlus was carried out for assessing the performance of the test room with the BIPVT integrated on its facade through a parametric analysis of 14 scenarios in two conditions: a) receiving direct solar gains on the glazing surface and b) avoiding direct solar gains on the glazing surface. Additionally, a computational fluid dynamics (CFD) analysis of the BIPVT system was performed using ANSYS Fluent. The findings of this work demonstrate that the BIPVT has a good potential to improve the sustainability of the building by reducing the nominal energy needs to achieve thermal comfort, reducing up to 48% the total energy needs for heating and cooling compared to the base case. The operation mode must be adjusted to the other strategies already implemented in the room (e.g., the presence of windows and blinds to control direct solar gains), and the automatic operation mode has proven to have a better performance in the scope of this work.
- Retrofit measures evaluation considering thermal comfort using building energy simulation : two Lisbon householdsPublication . Gomes, Ricardo; Ferreira, Ana R.; Azevedo, Luís; Neto, Rui C.; Aelenei, Laura Elena; Silva, CarlosABSTRACT: Retrofit measures for buildings are in general evaluated considering the energy savings and life cycle cost. However, one of the main benefits, the increase of users comfort is very seldom analysed. In this work, two residential households representative of a large share of households in Portugal, were monitored and its thermal behavior was modeled using Energy Plus. The thermal evaluation of the pre-retrofit households shows that the winter season is problematic due to construction solutions and low availability for heating. The retrofit measures analysis was performed considering different retrofit solutions regarding envelope improvement and efficient systems implementation. In order to work around the question of comparing households that do not use energy for acclimatization and therefore have very low energy consumption, in the retrofit scenarios it was considered the thermal comfort evaluation value for the real case (pre-retrofit) and compared the energy consumption to achieve that same average comfort level (in this case avoiding high discomfort peaks). The measures that more rapidly pay the investment are those related with implementing active systems. The approach used in this paper, should be used in more calibrated models in order to have overall conclusions about the retrofit process at a larger scale.
- Retrofit measures evaluation considering thermal comfort using building energy simulation: two Lisbon householdsPublication . Gomes, Ricardo; Ferreira, Ana R.; Azevedo, Luís; Neto, Rui C.; Aelenei, Laura Elena; Silva, CarlosABSTRACT: Retrofit measures for buildings are in general evaluated considering the energy savings and life cycle cost. However, one of the main benefits, the increase of users comfort is very seldom analysed. In this work, two residential households representative of a large share of households in Portugal, were monitored and its thermal behavior was modeled using Energy Plus. The thermal evaluation of the pre-retrofit households shows that the winter season is problematic due to construction solutions and low availability for heating. The retrofit measures analysis was performed considering different retrofit solutions regarding envelope improvement and efficient systems implementation. In order to work around the question of comparing households that do not use energy for acclimatization and therefore have very low energy consumption, in the retrofit scenarios it was considered the thermal comfort evaluation value for the real case (pre-retrofit) and compared the energy consumption to achieve that same average comfort level (in this case avoiding high discomfort peaks). The measures that more rapidly pay the investment are those related with implementing active systems. The approach used in this paper, should be used in more calibrated models in order to have overall conclusions about the retrofit process at a larger scale.