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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

Fuel cells (FCs) are among the key technologies that Europe will have to rely on in order to comply with the most recent environmental targets inspired by decarbonization and circular economy. The assessment of the real advantages of using FCs for producing energy must include a reliable analysis of the energy and environmental impacts during the life cycle of these systems, including the raw materials supply, production, use, and disposal. In this context, the life cycle assessment (LCA) is a well-established methodology for assessing the eco-profile of products and services and for identifying the components and the life cycle steps having the largest contribution to energy and environmental impacts. In the chapter, authors focus on the analysis of two types of FCs: solid oxide FCs and polymer electrolyte membrane FCs. Authors describe the FC technology, the sectors of application, and the FC materials and components. A literature review of available LCA researches is also discussed to point out the environmental impacts of the FCs and the methodological issues that can arise in the study of a FC.

The bio-wastes pyrolysis is a waste to energy strategy that converts bio-wastes into valuable products (bio-char, bio-oil) with wide use in the agri-food sector. However, limited efforts are paid to the investigation of its environmental sustainability: in this context, the study contributes the need towards the assessment of a wide range of environmental impacts for the pyrolysis process of different types of bio-wastes under different operating conditions. The study estimates the potential environmental impacts related to bio-char production from the pyrolysis of several different agro-industrial residues and different temperatures and identifies the process “hot spots”. The analysis is carried out through the life cycle assessment methodology. The functional unit for the analysis is 1 MJ of thermal energy potentially released during the complete combustion of bio-char obtained from the pyrolysis process. The study highlights that, under the examined conditions, the type of biomass affects the environmental impacts of the pyrolysis process more than the peak pyrolysis temperature. Among the biomasses tested, bio-char obtained from orange peels has the lower environmental impacts, with an average percentage difference of about 16% compared to bio-char obtained from olive tree trimmings that has the worst environmental performance. For each biomass, the impacts associated to bio-char obtained with different operational temperatures have percentage differences in general lower than 5%. A contribution analysis shows that the electricity consumed during the operational phase is responsible for the largest impacts in all the examined impact categories, followed by bio-wastes transportation. In detail, the contribution of the electricity to the total impact ranges from minimum values of about 44% (for cumulative energy demand) up to 91% (for terrestrial eutrophication), while transportation contributions range from a minimum of about 4% (for terrestrial and marine eutrophication) to 36% for mineral, fossil and renewable resource depletion. Therefore, the use of more energy efficient processes and technologies and the diffusion of distributed pyrolysis systems near farms can significantly improve the environmental performance of the system examined.

In response to the disruptive changes brought upon our society by the COVID-19 pandemic, most work activities and service providers had to resort to remote working. This is credited to reduce emissions for transportation, however the role of forced confinement within dwellings, especially if not designed for hosting working stations, deserves to be properly evaluated in terms of both user acceptance and long-term environmental impact. In this work, a dedicated survey campaign is used for investigating the potential pros and cons of remote working. In more detail, logistic regression and generalized linear models are used for capturing the effect of several independent variables on user acceptance of remote working. At a later stage, the main greenhouse gas emissions produced by each participant before and during remote working are assessed. According to the obtained results, the greater the distance between their home and workplace, the higher the acceptance score declared by the survey participants about remote working. Additionally, higher incomes and better-quality lifestyles with larger devotion to leisure activities also provide higher acceptance. Finally, the existence of a comfortable room to be used for work activities plays a crucial role on the declared acceptance. From an environmental point of view, remote working is always sustainable in case of long commuting distances (above 10 km) are avoided on a daily routine. In conclusion, a sensible use of remote working could reduce the environmental impact of any organization employing desk-workers as well as improve their work satisfaction and lifestyle.

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.

This paper aims at assessing the embodied energy and greenhouse gas emissions (GHGs) of two building envelopes, designed for a two floors semi-detached house located in the Central Italy. The analysis is performed by applying the Life Cycle Assessment methodology, following a from cradle-to-gate approach. Fixtures (windows and doors), external and internal opaque walls, roof and floors (including interstorey floors) make the building envelopes. Their stratigraphy allows for achieving the thermal transmittance values established in the Italian Decree on energy performance of buildings. The two examined envelopes differ only for the insulation material: extruded expanded polystyrene (XPS) or cellulose fibers. The results shows that the envelope using cellulose fibers has better performance than that using XPS: it allows for reducing the embodied energy and the GHGs of about 13% and 9.3%, respectively. A dominance analysis allows to identify the envelope components responsible of the higher impacts and the contribution of the insulating material to the impacts. The study is part of the Italian research “Analysis of the energy impacts and greenhouse gas emissions of technologies and components for the energy efficiency of buildings from a life cycle perspective” funded by the Three-year Research Plan within the National Electricity System 2019-2021.

The topic of low-energy buildings received a widespread and growing interest in last years, thanks to energy saving policies of developed countries. The design of a low-energy building is addressed with energy saving measures and renewable energy generation, but the correct assessment of phenomena occurring in a building usually requires to perform dynamic simulations and to analyze multiple scenarios to attain the optimal solution. The optimality of a technical solution may be subject to contrasting constraints and objectives. For this reason, designers may employ mathematical optimization techniques, a non-familiar topic to most of building designers. In this paper, a review on optimization of low-energy buildings design is provided, in order to collect the results of previous works and to guide new designers. The topic received an increasing interest in last years, with multi-objective optimization and genetic algorithms being the most popular. The most common objective functions are the costs and the operating energy consumption, while the environmental aspects are often neglected. As low-energy buildings should reduce the global energy demand, their design may benefit enormously from the assessment of energy consumption and environmental impacts in the whole life cycle, even in a simplified way.

The existing policy for greenhouse gas (GHG) abatement aims at decarbonisation of the power sector. The interrelations between the power sector and other economic sectors raise a question of whether the GHG emission reduction policy in the power sector is as effective as it is claimed. Consequential life cycle assessment (CLCA) has been developed to assess the environmental impacts of any industrial/productive sector in relation with changes in the policy and its indirect impacts on other economic sectors. This review is conducted on CLCA studies in the power sector in terms of system boundaries expansion and socio-economic interactions and the ability to quantify indirect environmental impacts. It is indicated that CLCA expanded the system boundaries by applying mutatis mutandis assumption to include several affected products with various scales of change. Economic modelling tools are frequently applied to make assumptions on the extent of change. The applications of these tools also help to identify the environmental profile of product systems and the socio-economic changes such as economic growth and consumer behaviours. Thanks for the expansion of system boundaries and inclusion of socio-economic interactions, the total environmental impacts of power sector are comprehensively quantified. The variations of the total environmental impacts, with different magnitude of change, were observed in several reviewed case studies. In term of GHG emissions, some products become cleaner, for example battery; however, in most of the cases, the power system in general becomes more polluted when indirect impacts on other economic sectors are included.

This study presents the comparison of the life cycle performance of two different urban energy systems, applied to a large mixed-use community, in Calgary (Canada). The two systems investigated consist of an energy efficient conventional system, using heat pumps for heating, cooling and domestic hot water; the second design widely deploys solar thermal panels coupled to district heating infrastructure and a borehole seasonal thermal storage. The analysis is based on the Life Cycle Assessment 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 explores the performances of the systems on a life cycle perspective thanks to the use of different indicators of ILCD 2011 Midpoint impact assessment method. The solar-based system, performs better than the conventional system from the point of view of all indicators used in the study. In detail, ozone depletion and land use can be reduced of about 79.7% and 27% respectively, while the remaining impact categories show a reduction of about 39–56%. These results can be extended to other similar systems operating under similar weather constraints, energy systems included in the operation, thermal loads requirements. Moreover, the study is based on the premises and assumptions of real documented case studies in Canada, thus further reinforcing the solidity of the results.

Over the years, different types of smart windows have been tested and developed. In this study, an innovative prototype of a photovoltaic smart window, that integrates luminescent solar concentrators, was analysed. The device independently regulates the movement of the shading system and allows energy surplus, through the electricity generated by modules. Considering the peculiar structure (characterized by the presence of a light shelf) and the thermal characteristics of the device, the analyses focused on optical, thermal, and electrical performances, comparing them with those of a traditional window. The analysis followed an experimental approach that involved lighting and electrical monitoring studies in a real test room, to create validated models for conducting simulations in larger buildings. The results were expressed through the study of illuminance maps, electricity generation obtainable from the integrated photovoltaic technology and in terms of energy savings. Energy generation accounts for around 10 Wh/month, with up to 50% improvement from the perspective of energy use for heating and cooling. The technology proves effective in allowing efficient overall energy performances while generating enough energy to operate the smart window control systems.

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.

Net Zero Energy Buildings can play a key role in reducing the energy use, greenhouse gas emissions and the use of natural resources associated to the built environment. It is widely recognized that in low energy building a shift in relevance may occur from the operational to the embodied impacts. However, building performance assessment focus mostly on the operational phase and on primary energy consumption. This study aims to assess the energy and environmental impacts of a residential net zero energy building expanding the analysis to the full life cycle and to a wide range of environmental impact categories. The methodological approach integrates a non-steady state building energy simulation and the life cycle assessment methodology. The analysis is performed by considering four different design scenarios using alternatively two thermal insulation materials (extruded expanded polystyrene (XPS) and cellulose fibres (CF)) combined with two configurations for a building integrated photovoltaic system (with and without a battery storage system). The main results highlight that the CF/battery storage system scenario has the lowest impact in almost all the energy and environmental categories investigated, while the configuration with XPS and without battery storage system has the worst performances. In detail, the indicators “global energy requirement” and “climate change” are 18% and 34% lower than the XPS/no battery scenario. However, the impact increases in terms of resource depletion (4%). This outcome confirms the importance of a life cycle perspective to orient the low energy buildings design process towards more sustainable solutions. Moreover, very different results can be achieved if the credits beyond the building system boundaries are included or not in the balance. In detail, if system boundaries are expanded to include the net environmental credits, the configuration with CF and without battery storage system is the best, while the XPS/battery storage system one is the worst. “Global energy requirement” and “climate change” decrease, respectively, by 37% and 29% from XPS/battery configuration to CF/no battery storage configuration. Therefore, the management of the credits beyond the building system boundaries is an aspect not to be overlooked in similar approaches while defining a clear and unambiguous procedure to manage it in the perspective of a wide diffusion of low energy buildings.

The food sector is responsible for a considerable impact on the environment in most environmental contexts: the food supply chain causes greenhouse gas emissions, water consumption, reduction in cultivable land, and other environmental impacts. Thus, a change in food supply is required to reduce the environmental impacts caused by the food supply chain and to meet the increasing demand for sufficient and qualitative nutrition. Large herds of livestock are inappropriate to achieve these goals due to the relevant impact of meat supply chain on the environment, e.g., the land used to grow feed for animals is eight times more than that for human nutrition. The search for meat alternatives, especially for the intake of critical nutrients such as protein, is a consequent step. In the above context, this paper summarizes the health aspects of protein-rich food alternatives to meat and carries out a literature review on the life-cycle environmental impacts of this alternative food.

During the last decade, increasing attention has been paid to the emerging concept of Positive Energy Districts (PED) with the aim of pushing the transition to clean energy, but further research efforts are needed to identify design approaches optimized from the point of view of sustainable development. In this context, this literature review is placed, with a specific focus on environmental sustainability within innovative and eco-sustainable districts. The findings show that some sustainability aspects such as sustainable food, urban heat islands mitigation and co-impacts, e.g., green gentrification, are not adequately assessed, while fragmented thinking limits the potential of circularity. In this regard, targeted strategies should be developed. On the other hand, the Key Performance Indicators framework needs some integrations. In this direction, indicators were suggested, among those defined in the Sustainable Development Agenda, the main European standards and initiatives and the relevant literature experiences. Future outlooks should be directed towards: the harmonization of the Life Cycle Assessment in PEDs with reference to modeling assumptions and analysis of multiple impacts; the development of dynamic environmental analyses taking into account the long-term uncertainty due to climate change, data availability and energy decarbonization; the combination of Life Cycle Assessment and Key Performance Indicators based techniques, from a holistic thinking perspective, for a comprehensive design environment and the analysis of the contribution of energy flexibility approaches on the environmental impact of a project.

Il presente lavoro descrive i risultati dell’analisi di inventario di un impianto integrato “gassificatore – cogeneratore” impiegato per la valorizzazione energetica di biomasse residuali di origine forestale, in un’ottica di ciclo di vita. Il sistema gassificatore – cogeneratore è un prototipo realizzato presso il laboratorio di Bioenergia e Biocombustibili dell’Università di Bolzano. L’impianto è costituito da un gassificatore down-draft e un cogeneratore con motore diesel dual – fuel e una potenza elettrica di 3 kW. L’analisi di inventario è stata sviluppata in accordo agli standard della serie ISO 14040. L’unità funzionale (UF) è 1 kWh di energia elettrica immessa in rete. I confini del sistema sono stati definiti secondo un approccio “gate to gate” e hanno incluso le fasi di gassificazione della biomassa, di purificazione del syngas e il processo di produzione di energia elettrica e termica nel cogeneratore. Il risultato dello studio è il bilancio ambientale, riferito all’UF, espresso in termini di flussi energetici e di massa in ingresso al sistema e di flussi in uscita in termini di prodotti, co-prodotti e rifiuti. Il bilancio ambientale dei processi di foreground è corredato dei dataset selezionati per la modellizzazione dell’inventario di ciclo di vita dei processi di background relativi all’energia e ai materiali utilizzati nel sistema in esame. L’analisi si inserisce in uno studio più ampio sviluppato nell’ambito del PRIN 2017: “BIOmasses Circular Holistic Economy APproach to EneRgy equipments (BIO–CHEAPER)” che ha tra gli obiettivi quello di valutare gli impatti energetico-ambientali connessi alla valorizzazione energetica di diverse tipologie di biomasse residuali

Il presente studio si propone di valutare gli impatti energetico - ambientali connessi al processo di pirolisi di rifiuti agro – alimentari attraverso l’applicazione della metodologia Life Cycle Assessment seguendo un approccio dalla culla al cancello. Il sistema analizzato consiste in un reattore di pirolisi al quarzo a letto fisso realizzato a scala di laboratorio. L’unità funzionale per l’analisi è 1 MJ di energia termica potenzialmente generata dalla combustione del bio-char prodotto dalla pirolisi di residui della potatura di olivi e dei residui della spremitura delle arance a tre diverse temperature (400 °C, 500 °C e 650 °C). Lo studio fornisce un ampio set di indicatori ambientali e identifica gli hot spot del processo esaminato. I risultati ottenuti possono costituire un supporto scientifico nella valutazione delle strategie di gestione dei rifiuti conformi ai principi dell’economia circolare e nell’eco-design degli impianti di pirolisi.

In recent years, a growing attention on environmental issues affecting all fields and procedures of the productive sectors has raised, aiming to reduce energy and raw-material consumptions and pollution effects on environment. Due to the involved volumes and to the nature of the related materials and productive processes, the civil and road sectors have been strongly invested by this change of perspective. Therefore, a proper estimation of the environmental impacts for the entire life cycle of the asphalt mixtures for road construction and maintenance activities is extremely important. For performing similar investigations, Life Cycle Assessment (LCA) has become one of the most reliable and effective methodologies, assuring the possibility to include in a comprehensive analysis all the relevant processes and products, such as raw material extraction, production, use and final recycling. In this paper, a specific LCA analysis, based on the international standards of the ISO 14040 series, of an asphalt mixture is performed, based on primary data, i.e. through data collected or measured directly at a production plant in Sicily. The results, presented in terms of aggregated environmental indicators, are useful for better understanding the overall impact of the productive process, as well as the contribution of its single phases. The results of this research can provide a more reliable and exhaustive analysis on the environmental impacts of an asphalt mixture, assuring a useful numerical reference to producers, contractors and designers that can assume more conscious, informed and sound decisions.

Fuel cells are considered one of the key technologies to reach the ambitious European goal of a low carbon economy, by reducing CO2 emissions and limiting the production of other pollutants. The manuscript presents an assessment of the life cycle energy and environmental performances of a solid oxide fuel cell system for household applications using primary data from the manufacturing phase and experimental data for the start-up and operation phases. The Life Cycle Assessment methodology is applied, based on a functional unit of 1 MJ of exergy and includes the life cycle steps from the raw materials extraction to the maintenance. The results show a particular relevance of the operation stage on the impacts (about 98% of cumulative energy demand and more than 63% of about half of the examined environmental impacts), mainly due to the fuel supply and, focusing on climate change, to the CO2 emissions during the conversion of chemical energy into electricity. Manufacturing step is the main responsible of the remaining half of the impacts, with a contribution higher than 38%, mainly imputable to the stacks production. For almost half of the examined impact, a contribution of 20–30% is caused by the maintenance step, with a relevant contribution of the stacks and DC/DC booster substitutions. The analysis highlights that eco-design solutions of the assessed system can be traced in the improvement of the energy system efficiency and reduction of emissions during the operation, and in the increase of the durability of the system components, thus reducing the number of their substitutions. The results of a sensitivity analysis on the selection of the functional unit also clarified the importance of the recovery of the thermal energy generated by the fuel cells, in order to avoid concurrent energy generation from conventional sources.

The increasing use of renewable energy technologies for electricity generation in buildings will require a growing number of battery energy storage systems (BESS) to enhance the reliability of electricity supply. The increasing number of retired electric vehicle (EV) batteries, expected from the automotive sector, can match this demand as EV batteries can be used as BESS, considering that they have about 80% of their original energy capacity. In this context, the study aims at examining the system, consisting of a BESS made by retired Li-ion EV batteries, a photovoltaic plant (20 kW) and the electricity grid, that provides the electricity required by an existing nearly net zero residential building (25.000 kWh/year). The goal is to identify the optimal BESS size, expressed as energy capacity, for load match optimization and environmental impacts in a life cycle perspective. A BESS of around 46 kWh of energy capacity allows achieving significant results in terms of load match increase and environmental sustainability. The study includes an environmental assessment combining the load match analysis and the life cycle approach. It highlights the potential synergy inspired to the principles of the circular economy and of the industrial symbiosis, between the building and the automotive sector.

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.

The present study reports the features and set-up of a novel lab-scale fixed bed pyrolysis reactor for the production of solid and liquid bio-fuels from waste biomass. The fixed bed reactor is tested by carrying out pyrolysis experiments using two different waste biomasses. Olive tree trimmings (OT) and olive pulp (OP), olive cultivation and olive mill industries residues respectively, are pyrolyzed, under nitrogen atmosphere, between 200 and 650 °C for a residence time of 0.5 h. The OT and OP pyrolysis chars were characterized in terms of mass yields, high calorific values (HHVs), proximate and elemental analysis. Char mass yields, on a dry basis (d.b.), decreased from 91 to 23 wt% and from 93 to 32 wt% for OT and OP respectively with increasing pyrolysis temperature. HHVs increased between 200 and 325 °C up to 27.71 and 31.42 MJ/kg for OT and OP respectively but start decreasing when further rising the pyrolysis temperature to 24.36 and 28.44 MJ/kg for OT and OP respectively at 650 °C. The novel pyrolysis system set-up shows to be an efficient and effective tool to test biomass pyrolysis at lab scale level and adapt to produce high energy dense bio-chars for solid fuel applications starting from waste biomass. A preliminary life cycle assessment (LCA) of the pyrolysis process is carried out for the two examined waste biomasses, for calculating the life-cycle environmental impacts for the production of 1 MJ of thermal energy by pyro-char combustion.

In this study the environmental performance of a first of a kind integrated process based on supercritical water gasification and supercritical water oxidation, was evaluated using Life Cycle Assessment (LCA). The process was applied to the treatment of carbon black and used oil as model waste. Mass and energy balances were performed using Aspen Plus, and the environmental assessment was carried out through SimaPro. For the analysis was chosen a “From cradle to grave” approach, considering impact categories like climate change, ozone depletion, human toxicity, particulate matter, land use, resource depletion and others relevant indicators. The environmental profile of SCW-GcO process was compared to other technologies for treatment of dangerous wastes, solvent mixture and exhaust mineral oils by using Ecoinvent database. It is shown that SCW-GcO allows reducing impacts in different category and obtaining a favorable positive life cycle energy balance, achieving a good environmental performance.

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.

Anaerobic digestion (AD) uses biomass to produce biogas to generate heat and/or electricity. Several studies have reported that the adoption of AD may not necessarily lead to sustainable practices. For example, energy crops may cause significant impact due to the requirement of intensive agricultural practices. Then, residual biomasses are starting to be considered as alternative biomass for energy valorisation trough AD. In this context, this study assesses the potential environmental impacts related to the energy valorisation of agro-food industry waste though the Life Cycle Assessment methodology (ISO 14040). The system examined consists of a real anaerobic digester coupled with a combined heat and power plant (AD-CHP) operating in Sicily. The analysis accountsfor all the impacts occurring from the delivery of the biomass to the AD-CHP plant up to the electricity generation in the CHP. The main outcomes of the study include the eco-profile of the energy system providing electricity and the assessment of the contribution of each life cycle phase aimed at identifying the potential improvement area. Specifically, it highlights that direct emissions are responsible for the highest impact in global warming potential (66%) and feedstock transport contributes for the highest impact (64%) in mineral, fossil fuels and renewable depletion. The contribution of the electricity consumption to the different impact categories is in general relevant ranging from a minimum of about 22% for global warming potential up to 82% for freshwater ecotoxicity. The obtained results can provide useful information to improve the sustainability AD-CHP systems.

The photovoltaic (PV) sector has undergone both major expansion and evolution over the last decades, and currently, the technologies already marketed or still in the laboratory/research phase are numerous and very different. Likewise, in order to assess the energy and environmental impacts of these devices, life cycle assessment (LCA) studies related to these systems are always increasing. The objective of this paper is to summarize and update the current literature of LCA applied to different types of grid-connected PV, as well as to critically analyze the results related to energy and environmental impacts generated during the life cycle of PV technologies, from 1st generation (traditional silicon based) up to the third generation (innovative non-silicon based). Most of the results regarded energy indices like energy payback time, cumulative energy demand, and primary energy demand, while environmental indices were variable based on different scopes and impact assessment methods. Moreover, the review work allowed to highlight and compare key parameters (PV type and system, geographical location, efficiency), methodological insights (functional unit, system boundaries, etc.), and energy/environmental hotspots of 39 LCA studies relating to different PV systems, in order to underline the importance of these aspects, and to provide information and a basis of comparison for future analyses.

Purpose: Current greenhouse gas (GHG) policy aims at reducing emissions from power sector. However, there are some known trade-offs of GHG emission reductions, in terms of other types of environmental impacts and impacts on other economic sectors. Consequential life cycle assessment (CLCA) has been developed to assess the environmental impacts of the power sector in relation with changes in the policy and its indirect impacts on other economic sectors. Methods: A systematic review of CLCA method is conducted in the power sector. CLCA studies since 2005 are reviewed in terms of obtained results and methodology to identify whether CLCA is a more suitable approach for assessing environmental impacts of power sector in the context of GHG policy intervention, compared to attributional life cycle assessment (ALCA). Results and discussion: With CLCA the total environmental impacts/benefits of power system change when indirect impacts are accounted. The variations between the total environmental impacts quantified with CLCA and ALCA range widely from inconsiderable difference (less than 5%) to 200%, depending on the investigated product system. These variations originate from CLCA’s modelling principles of expanding the system boundary and the inclusion of socio-economic interactions. With the expansion of system boundary, CLCA covers affected products and accounts for their relevant environmental impacts, which makes the obtained results comprehensively quantified. At the same time, the inclusion of socio-economic interactions in CLCA improves its capability of identifying the connections between environmental impacts and social-economic changes such as economic growth and consumer behaviours.

In this study the environmental performance of a first-of-its-kind integrated process based on supercritical water gasification and oxidation (SCW-GcO), was evaluated using life cycle assessment (LCA). The process was applied to the treatment of carbon black and used oil as model wastes. Mass and energy balances were performed using Aspen Plus, and the environmental assessment was carried out through SimaPro. A “from cradle to grave” approach was chosen for the analysis, considering impact categories such as climate change, ozone depletion, human toxicity, particulate matter, land use, resource depletion, and other relevant indicators. The environmental profile of the SCW-GcO process was compared to other technologies for the treatment of dangerous wastes, solvent mixtures, and exhaust mineral oils by using the Ecoinvent database. It is shown that SCW-GcO allows for reduced impacts in different categories and the obtention of a favorable positive life cycle energy balance, achieving good environmental performance.

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.

International audience; This chapter describes the research experience of the International Energy Agency-Energy in Buildings and Communities Programme Annex 72 members on the application of multi-objective optimization processes for the selection of design or retrofit actions that allow for improving different aspects (energy, environmental, economic, etc.) of buildings in a life cycle perspective. Thirteen case studies were examined focussing on methodologies, applications and results and deriving generic conclusions and guidelines for building designers and decision-makers.