• Energy Research

AbstractIn this paper, a BIPV-PCM installed in an office building façade is investigated to approach the practical application of PV-PCM. Based on an updated mathematical model, theoretical simulation has been conducted for BIPV-PCM in this case. Furthermore, field testing for this case has also been performed to validate the model, and then the simulated and experimental results are compared and found in considerably good agreement. The experiments have been conducted during the winter time, as the prototype has been installed in January 2013. The experimental and numerical results show a good agreement, the maximum electrical efficiency of this BIPV-PCM can reach 10% and the thermal one 12%.

This study presents some preliminary results of an on-going European Project, RePublic-ZEB [1], where an analysis is conducted for identifying the cost optimal levels for the existing buildings, towards nearly Zero Energy Buildings (nZEB) performance. The analysis is applied to the reference building for an existing office building in five different countries: Italy, Portugal, Romania, Spain and Greece. The evaluation tool uses a new cost optimization procedure based on a sequential search-optimization technique considering discrete options [2] is applied and the results will be presented in terms of optimal "package of measures", energy consumption and global costs. Finally a cross-country analysis will be performed. © 2015 The Authors. Peer Reviewed

The 2018 revision of the European Performance Building Directive (EPBD) requires that from the year 2020 onwards, all new buildings will have to be “nearly zero energy buildings”. It also further promotes smart building technologies, raising awareness amongst building owners and occupants of the value behind building automation. The European Commission also identified, in 2011, Key Enabling Technologies (KETs), which provide the basis for innovation in the EU. In the frame of the SUDOKET project, the Solar XXI building was used as a pilot case, as innovative integrated solutions and technologies are monitored and controlled. The objective of this paper is to validate a simulation of the laboratorial test room in EnergyPlus with data obtained experimentally and determine the impact of the control systems on energy needs and on thermal comfort. Two systems, in particular, were studied: the Building-Integrated Photovoltaic (BIPV) and the earth tubes. Once validated, the simulation of the test room without the systems was created, allowing their impact to be determined. The results show that, for the analysed periods, BIPVs reduced the heating consumption by 22% while also increasing thermal comfort, and the earth tube system would reduce the cooling needs by 97%.

A computer system that consists of a set of several programs that share both the same geometric definition and a consistent set of definitions for construction elements, is under development. The system consists of a common program allowing different types of exportation to other simulation programs or to other modules. The main modules under development until now are: an interface to the Energy Plus program, which builds an "idf" file from a 3D geometric definition that was previously modeled in graphical mode; and a module, that will provide the necessary calculations to verify if a given shape fulfills the thermal regulation of buildings which is based upon the Energy Performance of Buildings Directive (EPBD) approved by European Parliament and Council. An interface with Radiance program is also being developed. Using this system, which has been designed firstly for architectural conception, the user can perform different simulations with different aims, but sharing the same architectural shape and construction types, in order to check if the building fulfills thermal Portuguese codes and to perform energy simulations with Energy Plus or Radiance. The use of this system has demonstrated that it can represent a great saving of time in simulations and helping to reduce the occurrence of design errors as well. Since it allows performing simulations in a very quick way it can contribute also to help architects on achieving better solutions while designing, in terms of the optimization of all the parameter evaluated. The use of energy plus to evaluate the comfort of the buildings while being design as shown that this methodology can help to find more sustainable solutions in terms of their architectural shape and construction elements.

Abstract 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.

CIES2020: As Energias Renováveis na Transição Energética: Livro de Comunicações do XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia Solar. Helder Gonçalves, Manuel Romero (Ed.). Lisboa, Portugal: LNEG, 3-5 Novembro, 2020, p. 1115-1121. ISBN: 978-989-675-076-3