Papers by Polo Lopez Cristina Silvia
The paper refers to the application of Building Integrated Photovoltaic (BIPV) systems for the re... more The paper refers to the application of Building Integrated Photovoltaic (BIPV) systems for the renovation of heritage buildings and urban landscapes, preserving their historic, material, aesthetic and natural values as well as lowering energy bills, increasing comfort, and improving their technical quality in terms of economic and environmental sustainability. Several criteria for the compatible use of BIPV systems in heritage context are proposed, also taking into account the perspective of architectural preservation, legislative framework, research projects, and the scientific literature. The research is structured in the following steps: (i) examination of existing criteria for acceptable use of BIPV on heritage sites; (ii) examination of the theory of architectural preservation and restoration; (iii) identification of a set of criteria for compatible insertion of BIPV; and (iv) assessment of these criteria on case studies. The study shows new opportunities of inserting new and emerging solar products in these contexts, especially thanks to the advanced customization possibilities to preserve their values by resembling other known building materials.
Sustainability, 2021
This paper proposes to identify an approach methodology for the incorporation of building-integra... more This paper proposes to identify an approach methodology for the incorporation of building-integrated photovoltaic systems (BIPV) in existing architectural heritage, considering regulatory, conservation and energy aspects. The main objective is to provide information about guidance criteria related to the integration of BIPV in historical buildings and about intervention methods. That will be followed by the development of useful data to reorient and update the guidelines and guidance documents, both for the design approach and for the evaluation of potential future interventions. The research methodology includes a categorization and analysis of European and Swiss case studies, taking into account the state of preservation of the building before the intervention, the data of the applied photovoltaic technology and the aesthetic and energy contribution of the intervention. The result, in the form of graphic schedules, provides complete information for a real evaluation of the analyze...
The present need to, dramatically, increase the renewable part of our energy supply is now pushin... more The present need to, dramatically, increase the renewable part of our energy supply is now pushing to maximize the Photovoltaics (PV) use on the building skins, making architectural and building integration a key issue. The European Directive 2010/31/EU establishes that starting from 2020 all new buildings will have to be Nearly Zero Energy Buildings (NZEBs). This will have an impact both in the building’s design by reducing the energy need by the building itself, and in the diffusion of renewable energies on site (near-by), which will produce the remaining part of energy if it is needed. PV will be gaining more and more relevance in the NZEBs design, thanks to its features and potentialities. “BIPV” is for technicians a well-known acronym to indicate PV module used in/on building when PV modules replace part of the traditional building elements of the envelope. Despite the discussion has been treated in several international projects and research programmes, settled up to find a co...
Governments are committed for decreasing greenhouse gases emissions to accomplish with the global... more Governments are committed for decreasing greenhouse gases emissions to accomplish with the global world set targets and towards NZEB, Net Zero Energy Buildings. Since new construction in Europe amounts only a small percentage of the total building stock, emissions from existing buildings cannot be ignored and it need to be reduced. Historic buildings, located in inner cities can also have room for some energy improvements, even across compliance with some modern standards and new construction techniques without damaging their main valuable architectural features. However, to meet these energy requirements it is necessary to promote the use of solar energy also on existing buildings, with or without particular historical values. This matter should thus become a top priority for mid-term future but today it is still not being properly exploited because of psycho-social barriers and lack of information. This paper presents some experience and the lesson learnt from different research p...
Urban densification and preservation of soil are a much discussed topics on which there is still ... more Urban densification and preservation of soil are a much discussed topics on which there is still little detailed research. In Switzerland these concepts are also acknowledged by visions and regulations at the federal level together with the importance of increasing energy supply by renewable energy sources and reducing the energy demand in-primis of existing building. The scientific community is however well aware of the need to enlarge the scale of analysis and to move to urban planning and design scales, which would better allow to take into account buildings shape, orientation and density and to detect possible cumulative effects limiting both the access to sunlight or solar gains and the possibility of equipping buildings with solar renewable systems. Moreover the impact of solar energy availability on existing buildings (in particular historical buildings) during urban transformation is still not well understood and is a matter of research. High-urban densification plans expect...
Sustainability, 2021
Within the framework of IEA-SHC Task 59, a multidisciplinary team of experts from around the worl... more Within the framework of IEA-SHC Task 59, a multidisciplinary team of experts from around the world has come together to investigate current approaches for energy retrofit of the built heritage with energy efficiency conservation-compatible measures, in accordance with cultural and heritage values, and to check and adapt the new standard EN-16883:2017 for historic buildings. This paper introduces activities within IEA-SHC Task 59 (Subtask C) focused on retrofit solutions with high impact on sustainability, energy efficiency, and the integration of renewables, which is the main goal of the solar group, focused on the integrated solar systems for historic buildings. Relying on an extensive, detailed, and accurate collection of case studies of application of solar photovoltaic and thermal systems in historic buildings, the assessment criteria of the standard have been reviewed and tailored for better solar implementation evaluation in a heritage context. All this is studied based on tec...
Sustainability, 2021
Historic, listed, or unlisted, buildings account for 30% of the European building stock. Since th... more Historic, listed, or unlisted, buildings account for 30% of the European building stock. Since they are complex systems of cultural, architectural, and identity value, they need particular attention to ensure that they are preserved, used, and managed over time in a sustainable way. This implies a demand for retrofit solutions able to improve indoor thermal conditions while reducing the use of energy sources and preserving the heritage significance. Often, however, the choice and implementation of retrofit solutions in historic buildings is limited by socio-technical barriers (regulations, lack of knowledge on the hygrothermal behaviour of built heritage, economic viability, etc.). This paper presents the approach devised in the IEA-SHC Task 59 project (Renovating Historic Buildings Towards Zero Energy) to support decision makers in selecting retrofit solutions, in accordance with the provision of the EN 16883:2017 standard. In particular, the method followed by the project partners...
Energy and Buildings, 2015
Whereas the modern architecture trends to an extensive use of glazing elements, buildings are inc... more Whereas the modern architecture trends to an extensive use of glazing elements, buildings are increasingly required to minimize the external energy demand, cutting down the energy needed and covering the residual demand using local energy generation solutions. In this context, the integration of optimized Semi-Transparent Photovoltaic (STPV) elements seems to present a promising energy saving potential, leading to significant reductions of the heating, cooling and lighting loads while the on-site electricity generation is supplied. In mild climate areas, building glazings are required to perform as solar control systems with a low solar factor in order to avoid overheating. However, g-value is frequently unavailable in the data sheet of the STPV elements, making it difficult to design the optimal building solution. In the present work, an indoor testing facility to analyze the solar factor of STPV elements has been further developed and validated. The operating principles of the calorimetric system as well as the experimental data obtained in the validation stage are presented. Results show that the system accuracy and sensitivity are fully adequate to perform detailed analyses of the solar factor of STPV glazings. Furthermore, g-value variations with the transparency degree have been analyzed over different electrical operating points.
2012 38th IEEE Photovoltaic Specialists Conference, 2012
ABSTRACT Today the market is open to new solutions that integrate solar thermal and photovoltaic ... more ABSTRACT Today the market is open to new solutions that integrate solar thermal and photovoltaic (PV) devices into a single element in order to generate electricity and heat, the so-called photovoltaic thermal (PV/T or PVT) hybrid solar collectors. The PVT modules improve the performance of PV modules keeping the cells cooled, increasing the overall efficiency of the panel. One stand test for hybrid PVT systems in order to develop new solutions and better knowing their performance under real operating conditions was designed. One innovative low-cost prototype of PVT module was developed using pipes of a floor heating system filled with a special brine to cool the PV cells. To improve module design and to check their behavior in typical domestic hot-water systems, two different PVT solutions, but with identical PV modules, were analyzed without the heat transfer system. This first test assessed modules overall performances. The features of two different collector types are also described.
Energy Procedia, 2014
Integrated photovoltaic BIPV components and the usage of renewable energy is already a standard f... more Integrated photovoltaic BIPV components and the usage of renewable energy is already a standard for reducing power consumption, but it would also be important knowing the possible contribution to improve comfort and health of building occupants and assessing an operational balance between the energy consumed and produced. This work describes the testing methodology employed by the authors to further study aspects linked to human comfort when using semi-transparent BIPV elements tested in a real setting and outdoor weather conditions. This research aims to analyse the whole set of issues that influence the global energy consumption in a building that use semi-transparent BIPV as a multifunctional building skin in order to improve quality in test and evaluation procedures of BIPV.
Energy Procedia, 2014
When installing photovoltaic modules on buildings, the mounting system significantly affects both... more When installing photovoltaic modules on buildings, the mounting system significantly affects both the heat-exchange between the module and the building envelope, and the operating temperatures of the PV modules, which in turn strongly influence the energy yield of the PV system. It is therefore important to be able to simulate and evaluate in advance the behaviour and the potential advantages of a certain type of installation. This paper presents the monitoring results of two examples of building integrated PV systems when installed as a façade cladding system or as roof tiles. The investigated parameter (i.e.: module temperature, electrical parameter, energy yield) can be used to predict the behaviour of such modules on real buildings.
Energy Procedia, 2014
When facing a retrofitting project which tries to improve the energy performance of a cultural he... more When facing a retrofitting project which tries to improve the energy performance of a cultural heritage building it is necessary to weigh carefully different aspects such as: energy efficiency, modernization and comfort. These energy improvements are desirable, but are not always possible without compromises. The situation may become slightly problematic when solar energy systems should be installed in historic buildings. The first step to overcoming barriers successfully, is to better understand the processes for both, historic preservation and solar PV project implementation, and to foster working with professionals in each sector to receive appropriate support and guidance. Establishing an assessment criterion for each step was the top priority of the research project presented here to assist in achieving a successful result.
Facades are the central element in the design and architectural definition of contemporary buildi... more Facades are the central element in the design and architectural definition of contemporary buildings. Several solutions, with different aesthetical appeal, perform the finishing materials of existing building and new constructions. A sustainable design process today is intended to produce high-performance buildings that are energy-efficient, healthy and economically feasible, by wisely using renewable resources to minimize the impact on the environment and to reduce, as much as possible, the energy demand. For this reason, the facade system plays an important role for achieving these energy and environmental goals and Photovoltaic can play a leading role in this challenge. Relying on a vast database of products and building examples, collected in different research projects, a multi-criteria analysis has been performed to compare BIPV solutions with other technological possibilities for facade (either traditional than innovative), in terms of technological, architectural, energetic,...
IOP Conference Series: Materials Science and Engineering, 2020
The integration between solar energy systems and building components is highly critical in sensit... more The integration between solar energy systems and building components is highly critical in sensitive heritage contexts. On the one hand there is the need for finding a balance between the preservation of the aesthetic appearance and the historical values, but on the other hand, finding the space where to effectively integrate the systems might be quite challenging. The solar systems can be divided in photovoltaic (PV) and solar thermal (ST) systems. Building Integrated Photovoltaics (BIPV) and Building Integrated Solar Thermal (BIST) are PV or ST panels integrated into the building envelope, combining the energy generation with other functions, such as noise, weather protection, thermal insulation, sun shadow, and other aspects. Nowadays, the dynamism of the market allows to design highly compatible products which look like traditional architecture materials. This situation fosters the integration of these products in the BIPV and BIST systems within the heritage sites, especially t...
Governments are committed for decreasing greenhouse gases emissions to accomplish with the global... more Governments are committed for decreasing greenhouse gases emissions to accomplish with the global world set targets and towards NZEB, Net Zero Energy Buildings. Since new construction in Europe amounts only a small percentage of the total building stock, emissions from existing buildings cannot be ignored and it need to be reduced. Historic buildings, located in inner cities can also have room for some energy improvements, even across compliance with some modern standards and new construction techniques without damaging their main valuable architectural features. However, to meet these energy requirements it is necessary to promote the use of solar energy also on existing buildings, with or without particular historical values. This matter should thus become a top priority for mid-term future but today it is still not being properly exploited because of psycho-social barriers and lack of information. This paper presents some experience and the lesson learnt from different research projects carried out in Switzerland by the Institute for Applied Sustainability to the Built Environment (ISAAC) to promote energy efficiency and regulate the use of solar energy system, such as PV, solar thermal and solar passive systems, on historical buildings. These research projects have enabled ISAAC to establish specific measures to integrate properly these solar systems with the collaboration and special contribution of different and same time divergent field experts.
Sustainability, Special Issue Advances in Historic Buildings Conservation and Energy Efficiency, 2021
This paper proposes to identify an approach methodology for the incorporation of building-integra... more This paper proposes to identify an approach methodology for the incorporation of building-integrated photovoltaic systems (BIPV) in existing architectural heritage, considering regulatory, conservation and energy aspects. The main objective is to provide information about guidance criteria related to the integration of BIPV in historical buildings and about intervention methods. That will be followed by the development of useful data to reorient and update the guidelines and guidance documents, both for the design approach and for the evaluation of potential future interventions. The research methodology includes a categorization and analysis of European and Swiss case studies, taking into account the state of preservation of the building before the intervention, the data of the applied photovoltaic technology and the aesthetic and energy contribution of the intervention. The result, in the form of graphic schedules, provides complete information for a real evaluation of the analyzed case studies and of the BIPV technological system used in historical contexts. This research promotes a conscious BIPV as a real opportunity to use technology and a contemporary architectural language capable of dialoguing with pre-existing buildings to significantly improve energy efficiency and determine a new value system for the historical building and its environment.
Sustainability, 2021
Historic, listed, or unlisted, buildings account for 30% of the European building stock. Since th... more Historic, listed, or unlisted, buildings account for 30% of the European building stock. Since they are complex systems of cultural, architectural, and identity value, they need particular attention to ensure that they are preserved, used, and managed over time in a sustainable way. This implies a demand for retrofit solutions able to improve indoor thermal conditions while reducing the use of energy sources and preserving the heritage significance. Often, however, the choice and implementation of retrofit solutions in historic buildings is limited by socio-technical barriers (regulations, lack of knowledge on the hygrothermal behaviour of built heritage, economic viability, etc.). This paper presents the approach devised in the IEA-SHC Task 59 project (Renovating Historic Buildings Towards Zero Energy) to support decision makers in selecting retrofit solutions, in accordance with the provision of the EN 16883:2017 standard. In particular, the method followed by the project partners to gather and assess compatible solutions for historic buildings retrofitting is presented. It focuses on best practices for walls, windows, HVAC systems, and solar technologies. This work demonstrates that well-balanced retrofit solutions can exist and can be evaluated case-by-case through detailed assessment criteria. As a main result, the paper encourages decision makers to opt for tailored energy retrofit to solve the conflict between conservation and energy performance requirements.
Sustainability 2021, 2021
Within the framework of IEA-SHC Task 59, a multidisciplinary team of experts from around the worl... more Within the framework of IEA-SHC Task 59, a multidisciplinary team of experts from around the world has come together to investigate current approaches for energy retrofit of the built heritage with energy efficiency conservation-compatible measures, in accordance with cultural and heritage values, and to check and adapt the new standard EN-16883:2017 for historic buildings. This paper introduces activities within IEA-SHC Task 59 (Subtask C) focused on retrofit solutions with high impact on sustainability, energy efficiency, and the integration of renewables, which is the main goal of the solar group, focused on the integrated solar systems for historic buildings. Relying on an extensive, detailed, and accurate collection of case studies of application of solar photovoltaic and thermal systems in historic buildings, the assessment criteria of the standard have been reviewed and tailored for better solar implementation evaluation in a heritage context. All this is studied based on technical compatibility, the heritage significance of the building and its settings, the economic viability, the energy performances and indoor environmental quality and use, as well as the impact on the outdoor environment of solar renewables.
Urban densification and preservation of soil are a much discussed topics on which there is still ... more Urban densification and preservation of soil are a much discussed topics on which there is still little detailed research. In Switzerland these concepts are also acknowledged by visions and regulations at the federal level together with the importance of increasing energy supply by renewable energy sources and reducing the energy demand in-primis of existing building. The scientific community is however well aware of the need to enlarge the scale of analysis and to move to urban planning and design scales, which would better allow to take into account buildings shape, orientation and density and to detect possible cumulative effects limiting both the access to sunlight or solar gains and the possibility of equipping buildings with solar renewable systems. Moreover the impact of solar energy availability on existing buildings (in particular historical buildings) during urban transformation is still not well understood and is a matter of research. High-urban densification plans expect a complex environment, where self-shading and the overshadows of adjacent buildings can dominate solar energy potential and daylight availability, but also the imposition towards greater energetic production of PV for new buildings would compromise the visual perception of existing settlement under transformation. But how do these urban revolutionary changes towards densification appear and impact? What are the implications for existing buildings during the process? What does solar energy mean for new/existing urban areas with protected heritage buildings? The aim of this research is to delve into these questions by analyzing a real case study in the city of Lugano Paradiso (Ticino). The City Centre district is currently undergoing a profound change towards densification of the urban environment with a new urban master plan and new zoning regulations.
Conference Paper 8th Euro-American Congress on Construction Pathology, Rehabilitation Technology and Heritage Management, REHABEND 2020; Granada; Spain; 24 March 2020 through 27 March 2020; Code 253609, 2020
The paper refers to the application of Building Integrated Photovoltaic (BIPV) systems for the re... more The paper refers to the application of Building Integrated Photovoltaic (BIPV) systems for the renovation of heritage buildings and urban landscapes, preserving their historic, material, aesthetic and natural values as well as lowering energy bills, increasing comfort, and improving their technical quality in terms of economic and environmental sustainability. Several criteria for the compatible use of BIPV systems in heritage context are proposed, also taking into account the perspective of architectural preservation, legislative framework, research projects, and the scientific literature. The research is structured in the following steps: (i) examination of existing criteria for acceptable use of BIPV on heritage sites; (ii) examination of the theory of architectural preservation and restoration; (iii) identification of a set of criteria for compatible insertion of BIPV; and (iv) assessment of these criteria on case studies. The study shows new opportunities of inserting new and emerging solar products in these contexts, especially thanks to the advanced customization possibilities to preserve their values by resembling other known building materials.
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Papers by Polo Lopez Cristina Silvia
ISBN 978-3-9812053-6-7