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European Union identified the battery value chain as strategic for achieving a sustainable and decarbonized economy. Focusing on the environmental sustainability of batteries, this paper presents an application of the Life Cycle Assessment methodology to three flow-redox cells characterized by electrodes made by different materials. The results are referred to one kWh of energy supplied by the cell during its useful life and are calculated following a “from cradle to grave” approach. Negligible differences (lower than 1.5%) are observed in the energy and environmental impacts of the three types of cells, mainly due to the type of electrode and the use phase. A dominance analysis shows that the cell manufacturing (including the raw materials supply) is responsible of more than 58% of most of the impact categories examined

To support the global transition towards a climate-neutral economy by 2050, countries all over the world are implementing low carbon and energy effi ciency policies. This is leading to a rapid increase in the installations of distributed generation technologies. A hybrid system consisting of two or more energy sources could provide a more reliable supply of energy and mitigate storage require ments. In this context, this paper develops an environmental early analysis by the employment of a simplified Life Cycle Assessment approach. The above mentioned approach is used to investigate the environmental performances of the hybrid energy system of the smart polygeneration micro-grid of the University Campus of Savona, which integrates photovoltaics and combined heat and power generators with an electricity storage system. Moreover, two further compari son scenarios are analyzed: electricity demand met by importing energy from the electricity grid (Scenario 1) and management of cogeneration plants to primarily satisfy thermal demand (Scenario 2). An early environmental assessment analysis shows that the cogeneration systems have a predominant weight on the majority of the environmental impact categories analyzed. On the other hand, the PV sys tems are the most responsible for the impacts on human toxicity cancer effects (35%), freshwater ecotoxicity (60%), and resource depletion (72%); while the energy imported from the grid has a predominant weight on freshwater eutrophi cation (55%). Finally, the results show that the alternative scenarios investigated are responsible for higher environmental impacts than the case study. The only exceptions are represented by the resource depletion for Scenario 1 and the global warming potential for Scenario 2. In fact, for these indicators, the base case shows higher environmental impacts than those of the alternative scenarios.

Ventilated Façades integrated with photovoltaic panels have become a popular way to improve both the thermal-physical performances of the existing built environment. The increased usage of not-programmable renewable energy sources implies the adoption of energy storage systems to mitigate the mismatch between the power generation and the building’s demand. Aiming at properly integrates a photovoltaic panel and a battery (Lithium based) as a module of an active ventilated façade, the prototype design has been carried out in terms of thermo-fluid dynamics performance. Based on experimental setup, a numerical study of flow through the air cavity of the active ventilated façade has been carried out by the fluid-dynamics Finite Volume code-Ansys-Fluent. The calibrated model was lastly used to perform a wide range of parametric analyses on different climate and boundary conditions to explore the viability of the prototype.

The European Union is moving towards a sustainable, decarbonized, and circular economy. It has identified seven key value chains in which to intervene, with the battery and vehicle value chain being one of them. Thus, actions and strategies for the sustainability of batteries need to be developed. Since Life Cycle Assessment (LCA) is a strategic tool for evaluating environmental sustainability, this paper investigates its application to two configurations of a sodium–nickel chloride cell (planar and tubular), focusing on the active material and the anode, with the purpose of identifying the configuration characterized by the lowest environmental impacts. The results, based on a “from cradle to gate” approach, showed that the tubular cell performs better for all environmental impact categories measured except for particulate matter, acidification, and resource depletion. With nickel being the main contributor to these impact categories, future sustainable strategies need to be oriented towards the reduction/recovery of this material or the use of nickel coming from a more sustainable supply chain. The original contribution of the paper is twofold: (1) It enriches the number of case studies of LCAs applied to sodium/nickel chloride cells, adding to the few studies on these types of cells that can be found in the existing scientific literature. (2) The results identify the environmental hot spots (cell configuration and materials used) for improving the environmental footprint of batteries made from sodium/nickel chloride cells.

The transition to a sustainable society and a carbon-neutral economy by 2050 requires extensive deployment of renewable energy sources that, due to the aleatority and non-programmability of most of them, may seriously affect the stability of existing power grids. In this context, buildings are increasingly being seen as a potential source of energy flexibility for the power grid. In literature, key performance indicators, allowing different aspects of the load management, are used to investigate buildings’ energy flexibility. The paper reviews existing indicators developed in the context of theoretical, experimental and numerical studies on flexible buildings, outlining the current status and the potential future perspective. Moreover, the paper briefly reviews the range of grid services that flexible buildings can provide to support the reliability of the electric power system which is potentially challenged by the increasing interconnection of distributed variable renewable generation.

Although nearly zero energy buildings have attracted growing research attention, literature analysis shows that only a limited number of researches try to couple load match/grid interaction issues and environmental impacts in early design stages. The study proposes a novel multidisciplinary design approach that allows to integrate these two conflicting aspects aiming to find trade-offs. The proposed approach has been applied to a building case study, equipped with a photovoltaics system without energy storage. The results show that even though on yearly basis the energy use (5,290 kWhe) is largely overcome by the on-site energy generation (8069 kWhe), an oversized PV system alone may not be the best solution for reducing the environmental impact of the building sector, besides not being very efficient in improving load match. Afterwards, a parametric analysis was carry out analysing three redesign scenarios, obtained varying the sizes of the PV system and installing different sizes of the storage systems. The results show that the use of storage systems, in addition to decrease the grid dependency, can increase the environmental benefits arising from the renewable energy sources (e.g. there is a decrease of global warming potential of 48%, compared to the base case, with 5.28 kWp PV system and 10 kWh storage system). Conflicting results are found according to specific impact categories and this suggests the need for a holistic approach, including different domains and indicators. In this context, the proposed approach can contribute to the transition toward low-carbon energy technologies, by supporting researches and designers to take environmentally sound considerations.

Il concetto di “edificio a energia netta zero” è stato recentemente implementato in tutti i regolamenti dei paesi europei. Tuttavia, l’approccio dettato dall’Europa si concentra principalmente sulla scala dell’edificio singolo, tralasciando alcuni aspetti riguardanti ad esempio l’interazione di generazione e carico tra edifici e le interazioni energetiche tra edifici. L’obiettivo di questo studio consiste nell’applicazione della definizione di net zero energy building ad un gruppo di edifici ubicati nell’Italia meridionale e caratterizzati da una destinazione d’uso variegata. Lo status quo di una ventina di edifici è stato simulato in ambiente energy plus e sono state successivamente selezionate una serie di soluzioni di retrofit applicate sia sull’involucro sia sugli impianti. Per raggiungere il target di edificio a energia netta zero si è ipotizzato di generare energia da sistemi fotovoltaici a scala di distretto. Grazie alle soluzioni di retrofit il quartiere avrà un consumo complessivo annuo di circa 628 MWhe, con una riduzione di circa il 28% rispetto alla situazione precedente. Tutte le soluzioni di retrofit proposte hanno tempi di ritorno dell’investimento inferiori ai 13 anni. The concept of “net zero energy building” has been recently implemented in regulations throughout Europe: however, some aspects regarding e.g. the interaction of generation and load between buildings and the energy interactions of each building between each other are often overlooked by an approach that focuses mostly on the single building scale. The objective of the study is to evaluate the potential for reaching net zero energy target on a district level in a mixed-use community in southern Italy. The paper identifies a district case study, made of around twenty buildings having mixed uses. The buildings were modeled in Energy Plus environment and a set of retrofit solutions are identified, including HVAC and envelope components, as well as energy generation options from photovoltaic systems. The retrofitted neighbourhood shows an overall electricity yearly energy use of around 628 MWhe, with a reduction of around 28% if compared to the existing one. All retrofit solutions show payback times below 13 years.

Climate Change is a priority, due to the large variety of implications and importance that it may cause in the next decades. In this context, the building sector is a significant contributor to greenhouse gas emissions. For this reason, buildings should be designed in such a way that they are responsible for fewer GHG emissions. In this context, the paper analyses the potential impact of climate change on the energy performances of buildings, with and without onsite generation from renewable energy, using a prototype building located in Messina (Italy) as case study. The analysis is based on Intergovernmental Panel on Climate Change RCP scenarios and the results confirm the already known overall increase in total energy consumption of a building due to climate change, with a relative decrease in heating demand and increase in cooling demand. The analysis highlights that an active building (including onsite renewable energy generation) responds better to climate change than a passive building in terms of Global Warming Potential. The use of local energy storage will greatly improve the flexibility of the building to load-match and at the same time it could reduce CO2eq emissions.

The study proposes a tool developed within the TRNSYS environment aimed at integrating its building simulation features during the use phase with a Life Cycle Assessment approach. The tool can be used to investigate the relevance of each life-cycle step of the building on the primary energy consumption and global warming potential. The Life Cycle stages can be modelled with different approaches: direct input of the embodied energy and global warming potential values for each life cycle step as defined in the EN 15978, use of an internal database of embodied energy and global warming potential of construction materials and energy systems, direct connections of building simulation outputs to the tool for the use phase. The proposed component is able to model correctly the LCA of a case study, obtaining negligible deviations from the results of a LCA study performed with a state of the art LCA software (lower than 0.05% for all impacts).

The concept of load matching refers to the simultaneous occurrence of loads and generation in buildings: it can be increased and optimised with modifications on both the energy demand and generation, but its pre-requisite is to guarantee passive energy efficiency. In the Mediterranean areas, a major challenge in new buildings is the increasing overheating even during mildly hot seasons. Ventilative cooling can be a potential solution to such issues and have an impact on load match in buildings and their grid interaction. The study analyses the potential of ventilative cooling to improve the load match in three different case studies in Italy. Ventilative cooling proved viable in moderately improving the load match and in more effectively reducing import of electricity from the grid under the appropriate climatic\indoor conditions. In addition, the thermal-physical features, energy generation and consumption characteristics of the buildings are a source of large variability in the results. Increases in the load cover factor through natural ventilative cooling among the case studies range from 0.5% (high-performance building, low cooling share) to 5% (prefabricated module, high cooling share on the total); energy import is reduced effectively from 1% up to 22% in the case of a Sicilian residential building.

Ventilated Façades integrating photovoltaic panels are a promising way to improve efficiency and the thermal-physical performances of buildings. Due the inherent intermittence of the non-programmable renewable energy sources, their increasing usage implies the use of energy storage systems to mitigate the mismatch between power generation and the buildings’ load demand. The main purpose of this paper is to investigate the thermo-fluid dynamic performances of a prototype integrating a photovoltaic cell and a battery as a module of an active ventilated façade. Based on an experimental setup, a numerical study in steady state conditions of flow through the air cavity of the module has been carried out and implemented in a fluid-dynamics Finite Volume code. In order to assess the viability of the prototype, the calibrated model was lastly used to predict thermal performance of the prototype on different climate conditions supporting its further improvement.

The concept of load matching refers to the degree of agreement or disagreement of the on-site generation with the building load profiles: it can be increased and optimised with modifications on both the energy demand and generation. In this context, the paper presents the load match analysis of a case study: a modular housing construction (it has an area of 45 m 2 and S/V ratio equal to 2.75 m −1 ) built in Messina (Italy). Moreover, in order to optimize the design of the next test module to be built, a parametric analysis was performed considering different scenarios on the generation side, to explore the effectiveness of the solutions sets used in current design and plan different solutions for the future ones. The results show that a 4 kWh energy storage system can increase the load cover factor by 94% (to 0.78) compared to the base case (0.41), while with only a 250 W fuel cell, the load cover factor can reach the value of 0.97.

The paper explores the energy performances and environmental impacts of a prefabricated building module located in Messina (Sicily, Italy) through an approach that combines both the non-steady state building simulation and the Life Cycle Assessment methodology. The building uses renewable energy technologies and is usable in emergency situations or as simply temporary housing. Results show that the building module causes the emission of 1.5 t of CO2eq/m2 and consumes 29.2 GJ/m2 of primary energy during its life cycle. The building achieves the Net Zero Energy Building target even if it has relevant environmental impacts in the materials production stage (72% on average of the total impacts while the use stage reaches the 23% on average). The construction and the end-of-life stages give a marginal contribution to the total impacts, since they account for the 1% and the 3%, respectively.

The building sector is one of the most relevant sectors in terms of generation of wealth and occupation, but it is also one of the main contributor to energy use and greenhouse gas emissions (e.g. at the European level it is currently responsible for 36% of CO2 emissions). For these reason this sector must play a key role in achieving a low-carbon economy consistent with the objective of holding the increase of the average temperature of the globe below 2 °C if compared to pre-industrial levels. In this context, the paper analyses the potential impact of climate change on the energy uses for heating and cooling in southern Europe, based on the assumptions of the latest Intergovernmental Panel on Climate Change (IPCC) future climate projections (assessment report 5). Different General Circulation Models (GCMs) were analysed using different metrics for selecting the most suitable one to be applied to building simulation. GCM data were used as input to a downscaling method known as “morphing”, to generate hourly weather files for 3 future time projections (2035, 2065 and 2090). Finally, in order to assess the building energy use for heating and cooling for the next century, energy simulations for a case study were performed. The results show, in all scenarios, consistent and large increases in future air temperature. The impacts of these driving forces on heating and cooling energy use are very relevant: the results show an overall increase in total energy consumption with a relative decrease in heating demand and increase in cooling demand: the yearly heating and cooling energy requirement in 2090 is expected to increase in a range of +50.8–119.7% if measures are not foreseen to counter and limit the effects of climate change.

Climate Change represents a priority, due to the large variety of implications and importance that it has reached throughout the last decades. In an effort to address this global and local challenge and in order to restrict temperature rise to 2 °C over the next century, it will need to address this topic from several angles, as confirmed by the last COP meetings in Paris and in Marrakech. In this context, the paper presents the modelling and assessment of ventilative cooling applicability in the future of the Mediteranean area under the effects of climate change. Results show that natural ventilation will continue to be of paramount importance in the Mediterranean climate but its highest effectiveness will be displaced from summer to spring and autumn.

The study aims at applying of Load Match and Grid Interaction indexes to a Net Zero Energy Building in order to optimize the performances of its energy systems. The case study is a modular prefabricated house that uses solar energy (photovoltaic) and natural gas (Fuel Cell) as energy sources and equipped with an Energy Management System addressing the optimal energy use.

The concept of Positive Energy District is one of the main areas of research and extensive applications of the principles of the clean energy transition within the building sector. In the past years, the most widely accepted definitions have focused specifically on carbon neutrality, while several other aspects regarding all sustainability approaches (including environmental, social and economic perspective) were included qualitatively or to a lesser degree. This paper proposes a discussion on the state of the art of the sustainability assessment of Positive Energy Districts, by investigating environmental, social and economic sustainability applications. The three sustainability dimensions are investigated individually first, while discussing methodological insights, key performance indicators used and quantitative results, as well as in an integrated perspective. Finally, the paper describes research gaps and areas for further development on the topic.

The paper presents an energy simulation-based study to investigate the impacts of climate change on the building energy use for heating and cooling in the Mediterranean basin.

Several climate models have been developed and used to forecast the effects of the climate changes, however the variability of results due to different models lead to a significant uncertainty on the estimation of the building energy use for the next century. In this context, the paper analyses this uncertainty and combines different climate models in order to improve the robustness of energy consumption predictions. The data of the climate models were then used to generate hourly weather files for the future period 2020-2099 and energy simulations for a case study located in Palermo (Italy) were performed. Results show a wide variability among all models (either alone or combined with our data-fusion method), with a mean variability of about 18% of the cooling energy requirements considering the RCP4.5 scenario. This reinforces the need for a more detailed validation and alternative climate change models for building simulation.