The emission saving related to the use of renewable energy sources: The case study of solar thermal collectors

The employment of renewable energy sources can represent a useful way to reduce air emissions released by conventional ones. In this paper we describe the results of a Life Cycle Analysis performed upon one of the most world-wide diffused renewable technologies: the solar thermal collectors for warm sanitary water. Two domestic solar plants have been investigated: mono-familiar plant with a passive flat collector and a large solar plant with forced fluid circulation. The first step has been the evaluation of direct and indirect emissions related to the production and use of plants. The main emissions have been categorised in three of the most important indicators (Global Warming Potential, …

LIFE CYCLE ASSESSMENT OF SOLAR COMMUNITIES: A SCENARIO ANALYSIS

The study proposes the comparisonof the life cycle performances of two different energy systems aimed at covering the needs of a large mixed-mode community, in Calgary (Canada). The two systems investigated are a“conventional” one, using heat pumps for heating, cooling and domestic hot water, and another one widely deploying solar thermal panels as well as a district heating infrastructure and a borehole seasonal thermal storage. The analysis is based on the LifeCycle Assessment (LCA) methodology and includes the stages of raw materials and energy supply, system manufacturing, use stage of the systems, generation and use of energy on-site, maintenance and components’ substitution, and explo…

To Assess the Validity of the Transfer Function Method: A Neural Model for the Optimal Choice of Conduction Transfer Functions

This paper presents a new mathematical approach applied to the Conduction Transfer Functions (CTFs) of a multilayered wall to predict the reliability of building simula- tions based upon them. Such a procedure can be used to develop a decision support system that identifies the best condition to calculate the best CTFs set. This is a critical point at the core of ASHRAE calculation methodology founded on the Transfer Function Method (TFM). To evaluate the perfor- mance of different CTFs sets, the authors built a large amount of data, subsequently employed to train a Neural Network Classifier (NNC) able to predict the reliability of a simulation without performing it. For this purpose all th…

Materiali isolanti per l’edilizia: uno studio di LCA

Il presente lavoro descrive l’applicazione della LCA per valutare l’embodied energy e le emissioni di gas serra (GHGs) di due sistemi edilizi (costituiti da involucro edilizio, pareti interne e pavimenti di interpiano) che differiscono per il materiale isolante: polistirene espanso estruso (XPS) o fibra di cellulosa (FC). I risultati mostrano che l’impiego di FC in alternativa al XPS consente di ridurre l’embodied energy del sistema edilizio di circa il 13% (l’aliquota di energia non rinnovabile, che rappresenta circa il 79-81% del totale, si riduce del 16,5%). Si osserva inoltre una riduzione del 9,3% delle emissioni di GHGs. Un’analisi di dominanza consente di identificare i componenti de…

The redesign of an Italian building to reach net zero energy performances: A case study of the SHC Task 40 - ECBCS Annex 52

In the framework of international actions to reduce the energy requirements and greenhouse gases emissions due to buildings, a new International Energy Agency task has been recently established in order to study Net Zero Energy Buildings (NZEBs). The commonly shared concept of NZEB, is a building whose annual balance of energy consumptions tends to zero. This concept is still too imprecise and the authors of this paper participate to the activities of SubTask B of IEA Task40 with the aim of establishing an internationally agreed understanding on NZEBs. The task is based on a common methodology for identifying and refining design approaches and tools to support industry adoption of innovativ…

The use of hydrogen in residential building climatisation: Technical and economic valuations

From biomass waste to tri-generation: a life-cycle experience in the “agro-combined” of Thibar

The paper presents a Life Cycle Assessment of the energy tri-generation from biomass waste in a plant located in Tunisia. The analysis included the plant construction and end-of-life, the supply of biomass, its use for biogas production and the electricity, heating and cooling generation from biogas. The study is one of the first applications of environmental analysis to tri-generation from biomass waste in developing countries. The results showed that the plant construction is responsible of 76% of primary energy consumption and gives a contribution higher than 88% on resource depletion and ionising radiation. The operation causes 66% of the impact on human toxicity - cancer effects and mo…

The use of hydrogen in residential sector: Economic aspects and environmental benefits

Historical Buildings in protected areas in Italy: a re-design study of a rural building

Historic and traditional buildings, including rural ones, are a territorial resource in Europe and constitute an integral part of the European’s cultural heritage. However they are often characterized by poor energy performances and a large potential for energy retrofit actions. On the other hand, the hardest part of retrofitting such buildings is the limited invasiveness that such actions need to have on the historical and heritage value of the building itself. The paper describes an experience of re-design of an existing rural building located in Sicily, inside the ancient Greeks “Valley of the Temples”. An energy audit was performed on the building, its energy uses thoroughly investigate…

Set up of a monitoring system for a preliminary evaluation of the Urban Heat Island in the town of Palermo

Surface energy balance of urban areas depends on the thermal features of building materials, as well as the overall urban layout and various anthropogenic factors. In extended urban areas, all these factors give rise to the phenomenon known as Urban Heat Island (UHI). From the point of view of urban health, the occurring of UHI drastically changes the fluid dynamic interaction between the air and the city surface, often preventing the dispersion of gaseous pollutants. In the last years in fact, several studies have monitored the increasing trend of breathing diseases and allergies correlated with the presence of UHI. Nowadays, a rational design of the urban areas within large towns should t…

Sustainable development in urban transport: Feasibility study for a plant to produce and store hydrogen from wind energy in the urban transport in Western Sicily

Life cycle energy sustainability assessment: an expanded framework for energy technologies

Life Cycle sustainability assessment is one of the most relevant tools delving in sustainability science, based currently on the triple bottom line idea, that is identified in the use of the three tools of Life Cycle Assessment (LCA), Life Cycle Costing (LCC) and Social Life Cycle Assessment (S-LCA). The methodology is structured on international regulations and is currently being applied to a wide set of products and systems. However, when targeting specifically energy technologies with this methodology some specific issues need to be taken in consideration before applying tout court the standard LCSA methodology. Energy systems – in particular those where fluid streams are used – have an …

Modeling of spanish household electrical consumptions: Simplified and detailed stochastic approach in trnsys environment

The initial assessment of electric energy demands of a building is a key element in the design process, that should be integrated in the earlier stages of the design of a net zero energy building. The objective of the study is the creation of predictive models of household electrical consumptions in the Mediterranean/Spanish climate and its implementation in TRNSYS 17 environment. The models offer both a simplified level of analysis, based on average seasonal electrical consumptions trends and a stochastic in-depth level for the simulation of peak loads through the compiling of multiple TRNSYS types.

An improved algorithm for thermal dynamic simulation of walls using Z-transform coefficients

The Transfer Function Method (TFM), recommended by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), is one of the most modern tools available to solve heat transfer problems in building envelopes and environments. TFM utilises Z-transform to solve the equations system that describes the heat transfer in a multi-layered wall. Due to an analogy with an electric circuit, it is possible to write the equations system in a matrix suitable to be solved by computer. Authors carried out an analysis on an historical building placed in the south of Italy to test the reliability and the quality of the thermal dynamic simulation using TFM. The analysis is performed usi…

Electric mobility in Sicily: An application to a historical archaeological site

Transports should be a key focus in the close future for decarbonization efforts, if the optimistic climate change mitigation objectives to be reached by 2050 on a global scale are to be met. Choosing an emblematic and historical location in the center of Sicily as object of the study, the potential for decarbonization and the reduction of the energy and environmental impacts in the site for electric mobility is assessed, by considering electric mobility scenarios based on different shares of electricity generated through renewable energy technologies. The analysis is performed by means of a life-cycle approach, through the use of the Life Cycle Assessment methodology. A parametric analysis…

ECO-design of solar driven systems: A performance comparison between the Italian and the Brazilian context

The paper shows a comparative analysis of the performances of two typologies of solar assisted cooling systems for building applications. In particular, Life Cycle Assessment (LCA) methodology is applied to assess the energy and environmental impacts of solar-assisted, heat-driven chillers and conventional compression chillers driven by grid-connected and stand-alone photovoltaic configurations. LCA is applied in compliance with the international standards of ISO 14040. System boundaries are defined following a “cradle to grave” approach, taking into account all the life-cycle phases including the raw materials supply, the production of the components of the plant, the operation and mainten…

A user-friendly software for sustainable management of urban areas

The need to collect and process information on urban ecosystem requires the introduction of innovative scientific tools, in order to analyze the current urban factors and to optimize the energetic and environmental profile of urban systems, with regard to carrying capacity and territorial needs and vocations. Addressing these needs requires two main elements: (i) public availability of transparent data; and (ii) availability of interactive software designed to make easier exploration of data, models and results. The aim of the present paper is to show a user-friendly software, which is designed as a decision support system for policy makers in the multi-criteria selection among different pl…

Buildings integrated phase change materials: Modelling and validation of a novel tool for the energy performance analysis

In this paper a novel dynamic energy performance simulation model for the Phase Change Materials (PCM) analysis is presented. The model is implemented in a suitable computer code, written in MatLab and called DETECt, for complete building energy analyses. In the presented model, the “effective specific heat” method is implemented. Here, the specific heat of each PCM layer changes as a function of the system phase and temperature in both melting and freezing processes. A model validation is carried out by comparing numerical results vs. measurements obtained at Solar Laboratory of Concordia University (Montreal, Canada). The simulation model allows exploring the potential of PCMs to increase…