The 9th International Conference on Energy and Environment Research

The novel development of clean sustainable fuels became a necessity in the last two decades as a response to crude oil depletion and global warming issues. In this context, we proposed, under the STELLAR project, the use of metal fuels as zero-carbon recyclable substitutes for conventional transport fuels through combustion/reduction cycles. Further, we investigated the use of concentrated solar power for the regeneration of those fuels, through the carbothermal reduction of the combustion oxide products, thus making the process more economically and environmentally beneficial. A solar process was developed to operate in batch or semi-continuous modes allowing the production of highly-pure Mg and Al metal powders. Promising results of 96% Mg and 77% Al yields were reached, using commercial magnesia and alumina in batch mode, by optimizing the process and reaction conditions. Similar yields were obtained using oxides produced from the combustion of Mg and Al metal fuels. Furthermore, we were able to surpass different experimental difficulties, encountered during the semi-continuous solar processing of magnesia, and attain up to 75% Mg yield. The regenerated Mg and Al powders were micro-sized and stable to be stored in native air with no re-oxidation risks.

Plastic products are essential parts of modern life as they are used in household items, packaging, electronics, building, automotive and many more. Amongst about 350 Mt of waste plastics produced worldwide, only about 20% are recycled and 80% are landfilled. The landfilled waste plastic has a serious negative impact on the environment which causes land diversity, havoc in marine, etc. Pyrolysis of waste plastics into usable energy products such as syngas, char and liquid oil can alleviate the burden of plastic waste management. While pyrolyzed liquid oil can be converted to plastic diesel through distillation and hydrotreatment processes, and char can be used for agricultural purposes, the pyrolysis syngas can be processed further through different reforming processes to produce H2. H2 is expected to dominate in fuel sector by substituting fossil fuels. In this paper, the experimental findings of waste plastics pyrolysis into oil, char and syngas are reported which shows that waste plastic can be converted to liquid oil by about 80%, remaining are approximately 10% char and 10% syngas. The possibility of H2 production from pyrolysis syngas through different reforming processes such as steam, partial oxidation, autothermal, plasma, aqueous phase, etc. are reviewed and critically analysed in this paper. The literature indicated that 530 Mt of H2 is needed to achieve net zero by 2050 worldwide. It is envisaged that converting all waste plastic into H2 will meet the demand of H2 and support net zero goal by 2050. Amongst different reforming processes, steam reforming is better than others to produce H2 from syngas. Therefore, the waste plastics can be a significant potential source of H2 and will benefit the society and the environment from negative impact and support achieving net zero by 2050.

Novel polyaniline (PANI)/zirconium vanadate (Zr-V) hybrid nanomaterials were prepared successfully via sol–gel technique of Zr-V onto the polymerization process of PANI. The most proper synthetic nanohybrid was characterized using SEM, XRD, FTIR, and TGA. The optimum ratio was recorded using the first route to be 1 PANI: 1.5 Zr-V. The synthetic nanohybrid showed a crystalline structure with nanotube branching (like cauliflower) morphology. Electrospinning technique was used to fabricate a composite nanofiber matrix using polyvinyl alcohol (PVA) with the optimum prepared PANI/Zr-V nanocomposite. Electrospinning parameters including flow rate, collecting distance, and applied voltage were optimized to attain uniform composite nanofibers. The gas sensitivity of the synthetic nanofiber composite towards liquefied petroleum gas (LPG) as a function of temperature was specified by measuring the conductivity of two sputtered electrodes of the sensor’s devices. The nanofiber matrix showed the highest sensing performance for LPG within 10 s at 200 °C.

Globally accumulated waste plastics have become an alarming environmental hazard for rapid increase in production and lack of recycling opportunities. In this study, mixed waste plastics containing an equal proportion of high-density polyethylene, polypropylene, and polystyrene were converted into oil through a 20 l batch pyrolysis reactor at 540 °C. Further upgrading of plastic pyrolysis oil (PPO) via a vacuum distillation process resulted in the separation of PPO into petrol cut (gasoline), diesel cut (diesel), and naphtha. This study defines the PPO diesel cut as plastic made diesel (PMD). The PMD fuel was blended with commercial ultra-low-sulphur diesel (ULSD) at 5% (defined as PMD5) and 10% (v/v) (defined as PMD10) to assess the performance and emissions characteristics of a naturally aspirated direct injection diesel engine. The results are highly comparable with the results of commercial ULSD. The maximum brake power of ULSD was only 0.9% higher than PMD10 fuel. The PMD5 and PMD10 showed lower brake specific fuel consumption (BSFC) and NOx emissions and comparable CO and CO2 emissions with ULSD in an unmodified diesel engine. Therefore, waste plastics can be considered an energy source by producing plastic diesel that can reduce environmental pollution and meet growing energy demand.

The building sector is a key component of energy efficiency and environmental strategies and initiatives worldwide due to its major contribution in the energy consumption and the corresponding share in carbon emissions. These goals along with the evolution towards digitalization of the building stock have called for smarter, flexible, and proactive buildings. In this context, a well-designed and properly installed and operated building automation and control system (BACS) is critical to achieving energy efficiency and environmental goals as well as providing high comfort levels and empowering occupants with information. In this study, an innovative tool ‘IBACSA’ for BACS assessment and building smartness evaluation is used as a basis to evaluate the design functionalities and services provided by the automation and control system. The tool assesses eight various technical domains in the building, covering 60 major building services, reporting the rating and performance of each domain, and considering multiple impact criteria. IBACSA is implemented in three Danish buildings of different type, size, and use. The BACS design and functionalities are evaluated and rated in each case, and actions for improvement are reported.

The construction sector is responsible for a significant part of global greenhouse gas emissions, with concrete being one of the most used building materials, which significantly affects the overall sustainability of the built environment. Thus, it is necessary to reduce its embodied energy and carbon emissions. For this purpose, a regular frame structure is analyzed in this work, for estimating the energy and carbon emissions of three different concrete formulations (C25/30, C25/30 with 30% recycled aggregates, and C35/45), following the guidelines defined in the EN 15084 and ISO 21930 standards, and also the Life Cycle Assessment methodology. To simplify the comparison between the concrete formulations, the chosen functional unit is the structural frame of the building, which is evaluated in this work following a “cradle-to-gate” approach. The inventory data was obtained by designing the frame structure, ensuring that it fulfills the structural safety requirements according to Eurocodes. Results show that C35/45 concrete has a significant carbon footprint of 307.62 kg CO2 eq per m3 and the values for C35/45 concrete, with and without 30% RCA, are respectively 11.4 and 10.3% lower. The structure built using C25/30 concrete with 30% RCA contributes 4.35% less to carbon footprint, corresponding to a reduction of 356.09 kg CO2 eq, than the structure built with C35/45 concrete. Concerning the embodied energy, results show that the C25/30 concrete has a lower embodied energy of 65,900 MJ-eq/FU than the C35/45 concrete with 68,134 MJ-eq/FU to which, reinforced steel contributes respectively, 67 and 64%.

At least 30% of the World’s energy consumption and greenhouse gas emissions originate from buildings. Thus, design decisions should be well studied during the design phase of buildings following energy efficiency approaches. Environmental variables and properties of the building envelope are significant for energy efficiency. Thus, this study aims to investigate the potential of a residential building in the Mediterranean climate of İzmir, Turkey, regarding decreasing energy use and understanding the significance of architectural decisions during the design stage of buildings. Eight design scenarios were created by defining seven variables affecting energy consumption for room electricity, heating, and cooling. The first three scenarios focused on environmental-related variables, i.e., surrounding buildings, ground surface materials, and building orientation, while the last five scenarios investigated building envelope-related variables, i.e., thermal transmittance of the wall, floor and roof, glass, window frame, and door types, shading elements, and natural ventilation. Then, energy modeling and simulation are applied to test their potential for minimizing energy consumption. Research findings proposed that early architectural design decisions significantly influenced the case building’s energy performance. Thermal transmittance of the building components provided an annual energy saving of 22.4%, thus, was seen as the best-performed variable for the case building.

The use of smart building solutions can bring advantages to both a building and its users. The main motivation of this work is to propose a solution based on internet of things devices to retrieve knowledge from historic data and, using the knowledge gained, contribute to the comfort of the user and the building’s sustainability. The use of internet of things devices enables the easy deployment of the proposed system in today’s buildings, where this kind of devices are commonly found. The knowledge regarding the role of each device and how they interact or impact each other will be studied by the proposed solutions that will deploy a continuous mechanism. The designed software architecture was developed in python, to allow easy implementation of different features. To test the proposed solution, it was used real data from a research building where several types of sensors were correlated to assess relations among data. The results show significant correlations between celling light consumption and the room’s light intensity sensor, and between the operation of air conditioning units and the room’s temperature, for example, data from 2 months, regarding air conditioner unit in room N102, demonstrates a − 0.85 correlation with the room temperature, when operating in cooling mode.

In a very early stage of implementation of a comprehensive experimental campaign for indoor radon assessment, a pre-evaluation selection of the variables that play a leading role in influencing expected results must be insightfully assessed. Hence, a practical methodology for variable selection based on an analysis of historic data plays a key role concerning radon potential assessment. Given the circumstances, this work is focused on the design of a qualitative pre-diagnosis model for the evaluation of radon potential in indoor environments, for different energy efficiency scenarios, by considering a set of relevant variables carefully selected to characterize occupants’ risk exposure. A prior survey was done to identify all relevant characteristics that most affect Indoor Air Quality (IAQ), mainly concerning local geology, built environment performance, and occupancy schedules. The selected parameters will be afterward weighted and combined into performance indicators through an evidence-based literature review. In the current early stage, the requirements to drive the software development are presented, together with a software architecture proposal. Finally, it is expected that this pre-diagnosis model will allow a more refined sample selection for indoor radon assessment, by choosing the most susceptible variables that influence radon potential in a given scenario.

A novel drop-in renewable fuel process was recently developed in project named ‘Robust and Efficient processes and technologies for Drop In renewable FUELs for road transport’ (REDIFUEL). The plant concept consists of a dual-fluidized bed gasifier, followed by a Fischer–Tropsch process and a hydroformylation process to produce a mixture of high-cetane hydrocarbons and C6-C11 alcohols. The Fischer–Tropsch process can also be preceded by synthetic gas production from renewable hydrogen and carbon capture. The environmental impacts of three production pathways for this fuel were compared with Life Cycle Assessment methodology. REDIFUEL has a climate change impact of 8.1–22.8 gCO2eq/MJ when produced from bark, 16.2–30.9 gCO2eq/MJ for short rotation coppice, and 11.1–19.8 gCO2eq/MJ for carbon capture. REDIFUEL production from short rotation coppice leads to the highest environmental impacts in 12–14 out of 16 impact categories assessed, especially in marine eutrophication. REDIFUEL from carbon capture has the lowest impacts in 9 out of 16 of the assessed environmental impact categories, but it leads to high material resource depletion impacts. REDIFUEL production from bark has the lowest impacts in 6 or 7 categories, and it was not associated with specific risks compared to the other scenarios.

Water consumption in buildings is a significant contributor to global freshwater utilization, yet research on the consequences of water usage has been limited. This study aims to evaluate the environmental implications of life-cycle water consumption in a multi-family residential building located in Doha, Qatar, using a comprehensive life cycle assessment (LCA). The analysis of the building was conducted using Building Information Modelling (BIM) as the primary tool. The LCA results revealed substantial impacts during the raw water treatment phase in Doha, which is characterized by energy-intensive thermal desalination. The water usage phase accounted for nearly half of the total impact observed. Throughout the life cycle of the modeled building, the cumulative annual emission reached 59,440 kg of CO2. This research provides valuable insights for water authorities and the building research community, facilitating the development of more sustainable water usage policies tailored to specific regions or countries. By understanding the environmental ramifications of water consumption in buildings, policymakers can make informed decisions to reduce the ecological footprint associated with water usage. Overall, this study underscores the importance of considering the life-cycle perspective in assessing the environmental impact of water consumption in buildings. It emphasizes the need for sustainable water management practices and encourages the adoption of efficient technologies and policies to mitigate the environmental consequences of water usage in residential structures.

Fischer–Tropsch (FT) catalyst production, use, and end-of-life (EoL) phases are often omitted in Life Cycle Assessments (LCA) studies as the required data are not publicly available. Consequently, the environmental effects of these catalysts are unknown. This study presents the prospective LCA of a novel cobalt-based FT catalyst. The objectives were to evaluate future production pathways and identify a best-case and a worst-case foreground scenario. The foreground was modelled with upscaled data from lab-scale experiments and patents. The effects of different prospective background scenarios were also investigated. A superstructure database was constructed with the Python library premise for 2030 and 2050. The climate change impact ranged from 0.088 to 8.77 kg CO2 eq/tonne syngas, and the metal depletion impact from 0.012 to 1.26 kg Fe eq/tonne syngas. The environmental impacts of the catalyst depended mainly on the catalyst loading and the EoL. The best-case scenario showed a high catalyst loading, regeneration at the EoL and autothermal reforming (ATR) of biomass for hydrogen production consumed in all processes. In the worst-case scenario, the catalyst is recycled, while the hydrogen is produced via ATR of natural gas. The background scenarios were less influential than the foreground scenarios.

The building sector is a major contributor to global greenhouse gas emissions, significantly impacting climate change. As a consequence of climate change, the demand for cooling in buildings is expected to rise, especially in countries with hot and arid climates where a substantial portion of energy is dedicated to cooling. This study aims to quantify the impact of climate change on the cooling demand of restaurant buildings in Qatar and assess the associated environmental implications. Future climate conditions were obtained from a fine-resolution regional climate model, specifically using the extreme Representative Concentration Pathway (RCP) 8.5 scenario. Energy analyses were conducted using OpenStudio software to compare reference and future climates. The simulation results were then used to perform a life cycle assessment. The findings indicate that by 2100, under the RCP 8.5 scenario, the annual cooling requirements of restaurant buildings in Qatar are projected to increase by 20%. Consequently, there will be a corresponding rise in power usage within these buildings, leading to increased environmental implications. Specifically, CO2 emissions are expected to increase by 14.6 metric tons by 2100. The study underscores the necessity of incorporating renewable energy resources in power production and integrating climate change considerations into building designs. These measures are essential for reducing carbon emissions, ensuring energy security, and mitigating the adverse impacts of climate change.

The growing electric vehicle and stationary storage markets raise the potential of second-life batteries (SLB) and question their environmental feasibility. Based on the life cycle assessment methodology, this study evaluates the impacts on climate change of three use cases (residential, industrial, and utility) for SLBs in Belgium. The assessed battery is a Renault Zoe40 pack, with lithium nickel manganese cobalt (NMC111) as the cathode active material. The residential use case is a domestic 4 kWp photovoltaic installation. The industrial use case is a 1,500 kWh installation providing behind-the-meter services. The utility use case contains SLBs with a total capacity of 20,000 kWh for in-front-of-the-meter services. The manufacturing and recycling impacts are allocated between the first and second life based on the delivered energy. As a result, the impact on climate change of the residential use case, the industrial use case, and the utility use case is 130.8 gCO2 eq/kWh, 146.6 gCO2 eq/kWh, and 168.3 gCO2 eq/kWh, respectively. The residential use case performs better, as it delivers more energy than the two other use cases. Both the residential and the industrial use stages are close to the impacts of first-life batteries used as a benchmark in this study, while the utility use case impacts are 40% higher than the benchmark battery.

The increasing social and political pressure on the development of more sustainable industries has led to an increase in the importance given by organizations to their products’ impact on the ecosystems. Carbon Footprint is a valuable tool in the assessment of those impacts. This study used Scope 1, 2 and 3 emissions to estimate the carbon emissions of a furniture industry plant and evaluate the evolution of those emissions in the 2013–2019 period. It was found that the main contributor to the studied plant carbon emissions is electricity consumption. In the scope of this work, it is highlighted the positive progress in the greenhouse gas emissions over the set period, mainly throughout 2017–2019, as a result of an important investment in solar energy.

Indoor air pollution in buildings poses a significant risk to human health and well-being, as it comprises a wide range of particulate matter, gaseous contaminants, mold, and pollen. Various strategies have been employed to address indoor air quality concerns, such as minimizing pollution sources, dilution, utilizing air cleaning devices, and implementing vertical greening systems. However, integrating sustainability into these air cleaning methods remains a crucial challenge. In light of this challenge, this study conducts a life cycle assessment to compare the environmental performance of two indoor air cleaning methods: commercial air purifiers (CAP) and active living walls (ALW). The results reveal the potential environmental benefits of employing ALW in indoor spaces, compared to commercially available air purifiers. Although the production impacts of CAP are relatively lower than those of ALW in this study, the comprehensive evaluation of the entire product life cycle demonstrates the significantly higher overall impacts of CAP. This preliminary investigation aims to assist building professionals by providing a framework for estimating the environmental cost associated with two distinct indoor air purification methods. By highlighting the advantages of ALW over CAP, this study contributes valuable insights into sustainable approaches for enhancing indoor air quality.

Studies have advocated that there is much less research on the impact of embodied energy. Researchers have asserted that a building’s embodied energy can be as high as 60% of the life cycle energy. However, there is insufficient research and understanding of embodied energy impacts and its relationship with material specification and service life. This research aims to fill this gap by investigating the life cycle embodied energy of a villa in the United Arab Emirates with particular emphasis on the wall assembly. The findings show that the embodied energy impact of the wall structure and wall finishes was found to be 19.7% and 11.7% of the villa’s life cycle embodied energy (LCEE), respectively. Alternative material service life (MSL) scenarios for the wall assembly shows that using minimum material service life (MSL) values results in a 54% increase in LCEE of the wall, and 74% increase in the LCEE of the villa. For maximum MSL, the findings show a 27% and 31% decrease in LCEE of walls and villa, respectively. Alternative wall finishes show that wallpaper as a replacement of water-based paint will increase the LCEE of the villa by 28%.

This study evaluates the embodied non-renewable primary energy (NRe) and the global warming potential (GWP) of six different concrete sandwich panels (CSP) with the same thermal transmittance. The functional unit (FU) of 1 m2 of CSP was considered for the cradle-to-gate life-cycle assessment (LCA). A high-performance concrete (HPC) layer was assumed for the outer and inner layers, and six different insulation materials were sandwiched in between: lightweight concrete (LWC), expanded-cork-panel (cork), glass wool, expanded polystyrene (EPS) 100% from virgin resources, EPS with 55% virgin material, and 100% recycled EPS. It was concluded that the scenario with the lowest GWP-value is the CSP with cork (30 kg of CO2-eq/m2), due to the carbon captured during the raw material growth. The CSP with virgin EPS is the scenario with the highest carbon footprint (68 kg of CO2-eq/m2), which could be significantly reduced if recycled EPS is used instead. The scenario with the lowest NRe-value is the CSP with recycled EPS (375 MJ/m2), followed by the scenarios with LWC (411 MJ/m2) and glass wool (424 MJ/m2), respectively.

Microalgae are considered an important alternative source for the production of lipids that are essential to the human organism. Nowadays, companies seek to reach an optimal solution—the balance between profit and sustainability, the latter coming from environmental performance. Therefore, this work compares the carbon footprint resulting from the use of different concentrations (M1, M2 and M4) of an organic fertilizer medium for obtaining lipids from microalgae. This LCA study considers a cradle-to-gate system, from cultivation and production to lipid extraction. A functional unit of 1 g of lipids was considered. The ReCiPe 2016 methodology was carried out to quantify the environmental impacts, with midpoint factors and an egalitarian perspective. According to the results M4 medium presents less carbon emissions than M1 and M2 media. Energy contributes to 98% of the GWP impacts. The lyophilizer represents 64.9% of the electricity consumption. In order to reduce the carbon footprint of this microalgae lipid production system, it is recommended to use a combination of less energy consuming lipid extraction methods and renewable energy sources, e.g. solar or wind energy.

This study combines the Life Cycle Assessment of the Italian electricity mix and external cost evaluation to develop an indicator useful for policy-making and evaluation. Even though external costs of air emissions are site specific, traditional LCA studies do not characterize environmental flows at geographical level. Therefore, we adapt the LCA model of the electricity consumption mix to include site specific information. The geographical characterization of LCA air emissions and benefit transfer techniques are used to calculate the indicator, which can be computed for different countries and economic aggregates and reference years, also into the future. In this work we apply the proposed methodology to two energy scenarios for Italy: one referring to 2019 and 2030. The first is based on the last available data, while the second on assumptions on the implementation of the European Union’s Green New Deal. The average external cost of the electricity consumption mix is 0.057 €2019/kWh in the 2019 scenario and as low as 0.019 €2019/kWh for the 2030 scenario. We also find that, even though emissions linked to electricity production take place in many countries around the world, most externalities occur within national boundaries and are linked to direct emissions from thermoelectric power plants.

The industrial production of poultry meat intended for human consumption has experienced continuous growth worldwide. In order to better understand the environmental performance of this industry and to formulate proposals for environmental improvement, it is of utmost importance the development of Life Cycle Assessment (LCA) studies. Hence, this work aims to evaluate a process of slaughter and preparation of chicken meat for human consumption, in a Portuguese company, following a “gate-to-gate” approach, and focusing on the energy consumption and climate change impacts. The functional unit selected for the study is 1 kg of chicken live weight at the company gate. The inventory data was gathered from real industrial practice, considering 2020 as the reference year. For the potential environmental impacts assessment, information on the characterization factors of the various impact categories was obtained from the EcoInvent V3.5 database, using the SimaPro V8.5.2 software. The results show the variation in energy consumption and carbon footprint throughout the year, depending on the quantity of chickens processed. In particular, it shows that the process is more energy efficient the greater the quantity/weight of slaughtered chickens. On average, the total energy consumption per kg of live weight of chicken is 1.18 MJ, to which contributes 67% of electricity, 31% biomass and 2% of propane gas. Therefore, the electricity consumption is what contributes most to the climate change impacts. Thus, future improvements to be proposed should focus on using renewable energy as an alternative or increasing its percentage in the process.

The search for sustainable extraction processes led to the development of innovative technologies with less environmental impact. Subcritical water extraction (SWE) and ohmic heating (OH) emerged as novel extraction technologies with higher selectivity and efficiency. The red algae Gelidium sesquipedale is mainly known for agar, its main hydrocolloid, widely used as a gelling agent in the food industry. Although SWE and OH are considered to be more sustainable than existing extraction technologies, an objective and quantitative assessment of their environmental performance is needed. Hence, this work aims to evaluate the carbon footprint of SWE and OH for native agar extraction, following the life cycle assessment methodology. The study focuses on native agar extraction, on a “gate-to-gate” approach, comparing the two extraction technologies. Concerning the process operating conditions, the OH extraction technology operates for 180 min at 95 °C, while SWE operates for 1 s at 140 °C. The functional unit is 1 kg of agar extracted, considering the experimental variability. Results show that OH has a lower carbon footprint than SWE (about 30% less, even considering the experimental variability). Considering two different electricity scenarios, the OH carbon footprint is 45 and 6 kg CO2 eq/kg agar for, respectively, the process powered by the Portuguese electricity mix and by Photovoltaic electricity.

Nanomaterials are widely applied to improve the performance of technological products and services due to their optical, magnetic, and electrical properties, and cost-efficiency. Although an extensive literature has focused on validating the technical feasibility of nanoparticle applications, the sustainability of these is an equally important topic, not deeply addressed yet. Therefore, this study aims to present a critical review of life cycle assessment studies concerning the use of nanomaterials in technologies. The gaps and barriers of these approaches are discussed, as well as the environmental performance of nanoparticles uses. Herein, the environmental hotspots of the processes involved are highlighted. The results demonstrated that energy-consuming stages are the main contributors to global warming and cumulative energy demand categories. In particular, the production of raw materials and the embodied energy in solvents and precursors contribute to 62% and 80%, respectively, of the cumulative energy demand impacts. To improve the environmental performance of nanomaterials applications, the adoption of the best available techniques is a key factor to mitigate the burdens observed. Furthermore, the upscaling of bench and pilot approaches and the reuse and recycling of the resources, in a circular economy perspective, could mitigate the environmental impacts in 20% and 73%, respectively.

The potential environmental impacts of producing lignin nanoparticles from wheat straw, on an industrial scale biorefinery, are evaluated following a prospective life cycle assessment (LCA) on a “cradle-to-gate” basis. This biorefinery includes emergent processes, such as organosolv, steam explosion and ultrasonication. The selected environmental impact categories include: climate change, cumulative energy demand, fine particulate matter formation, fossil resource scarcity, freshwater eutrophication and ecotoxicity, human toxicity, ionizing radiation, land use, mineral resource scarcity, ozone depletion and formation, terrestrial acidification and ecotoxicity and water use. The energy and chemical requirements highly influence the outcome of the proposed biorefinery’s environmental performance. Process optimization is however key to unlocking the potential for sustainable production of lignin nanoparticles. Further studies must be carried out in order to provide a more comprehensive understanding of the potential environmental impacts of industrial scale lignin nanoparticle production.

The change in the electric grid is a well-known and addressed topic. To achieve the very ambitious goals to prevent climate crises and to increase the participation of renewable generation without decreasing the reliability and security of the power system, demand side flexibility and demand response presents themselves as effective solutions to increase the needed flexibility. However, it is also necessary to make forecasts about the future of the system, which is more difficult for smaller loads in times of intense changes. This work addresses forecasts techniques and the predictions and expectations for achieving the ne zero emission 2050 scenario with focus on the European market. Even though the scenario presents itself as very challenging, the efforts are being made and the rollout plans, in many European countries are advanced. Changes in policies will also need to take a faster pace in the next few decades.

With the recent introduction of wind power generation of various scales due to its promise as a green energy resource, effectively managing the risk of fluctuations in wind power generation revenues has become an important issue. Against this background, this study introduces several weather derivatives based on wind speed and temperature as underlying assets and examines their effectiveness. In particular, we propose new standardized derivatives with higher-order monomial payoff functions, such as “wind speed cubic derivatives” and “wind speed and temperature cross derivatives.” In contrast to the existing nonparametric derivatives, the minimum variance hedging problem to find the optimal contract amount of these standardized derivatives is reduced to estimating a linear regression. We also develop a market trading model to put the proposed standardized derivatives into practical use and clarify the real-world implications of standardizing weather derivatives. Furthermore, to make trading more efficient, we propose a “product selection” strategy utilizing the “variable selection” approach of LASSO regression. Empirical analysis confirms hedging effectiveness comparable to existing nonparametric derivatives and reveals the effectiveness of the proposed derivatives standardization scheme as well as their trading strategies.

This paper is an analytical study of the optimal locations for tidal power generation in the Seto Inland Sea (SIS) in Japan. Multiple criteria were considered and evaluated to determine the optimal locations in the SIS to deploy tidal turbines. The tidal current speed was considered in a position of 30 m depth below the sea surface, given that most of the current commercial turbines are functioning between 20 and 50 m underwater. Also, the distance from ports and the coastlines was included for the installation and maintenance of tidal devices. The distance from existing power generation plants is also considered for the outcome energy to be easily inserted into the grid. Further, renewable energy resources from wind and surface waves are also considered in the analysis for the potentiality of a combined power generation. The national parks and restricted areas were eliminated from the selection process. The assessment process was conducted using the analytic hierarchy process (AHP) in combination with GIS-based spatial analysis. The results illustrated that Kurushima Strait, Bisan Strait, Naruto Strait, and Akashi Strait are suitable locations for tidal power generation. Moreover, Bungo Channel and Kii Channel are highlighted as potential sites for wind-wave power generation sites.

Due to the requirement of a long driving range of electric vehicles, the batteries must be packed ever more densely to increase the energy density. Thus, enormous heat generated is required to dissipate appropriately. This highlights the design challenge for thermally managing the densely packed batteries. In this study, the air cooling system integrated with non-electrically conductive liquid spray was used to enhance the cooling performance. The transient thermal response of a 40-cell lithium-ion battery pack was simulated to investigate the effect of the injection rate on the heat removal performance. From this study, it shows that the integrated liquid spray and air cooling system is highly capable of reducing the maximum temperature as well as the temperature uniformity of the battery pack compared to the dry air cooling scheme. When the HFE flow rate increased, the ability to reduce temperature became weaker. The optimum HFE flow rate should be determined. Thoroughly, spray cooling can be used securely for thermally managing the high heat flux of the densely-packed batteries.

The modeling of the gasification process using the thermodynamic chemical equilibrium of the process is an important tool when it is intended to obtain preliminary results or to scale-up an experimental installation. In this work, the gasification process of crude glycerol using steam as the gasification agent was modeled using stoichiometric and non-stoichiometric chemical equilibrium models. The effect of the gasification temperature on the equilibrium composition of the producer gas was evaluated. The simulation results were compared with the experimental results obtained in a downdraft fixed bed reactor. The results obtained showed that the two models predict the equilibrium composition in a similar way. They also showed that the gasification reactor is operating under conditions deviating from chemical equilibrium.

This paper presents the methodology and findings of a comprehensive study that in the selected key time milestones (2030, 2040, 2050) assess the ongoing energy transformation and its impacts within the interconnected European electricity system and overall energy security. The study models the expected development of the installed capacities of individual types of energy sources, respecting the steps leading to meeting the EU's ambitious binding climate and energy goals, as well as individual countries’ national plans like development of RES or phase out of coal and nuclear power plants. The majority output of the complex methodology is the evaluation of the state of shortages or surpluses of electrical energy in the European electricity system in the selected key time milestones. The model outputs show that increasing integration of RES may cause higher requirements for maintaining the EU's energy security. The current most significant barriers to the fulfillment of climate and energy goals for maintaining the EU's energy security include not the lack of generation resources but the inflexibility of the electricity system and the lack of technologically and economically efficient seasonal accumulation. It will be essential to involve all types of technologies providing flexibility and all energy market participants, including households.

The utilization of diatom biomass as a renewable resource for the production of high-value compounds has gained significant attention in the pharmaceutical, nutraceutical, and energy industries. To promote the feasibility and rapid expansion of this industrial sector, it is essential to develop accurate and multiscale models for predicting the production of microalgae biomass components. In this study, we present the initial steps towards the development of a multiscale model capable of forecasting microalgae production in pilot-scale photobioreactors. The framework integrates a genome-scale metabolic network model of the diatom Phaeodactylum tricornutum with pilot-scale bubble column photobioreactor parameters. By integrating experimental data and taking into account site-specific climate conditions over a one-year operation, the model predicts biomass production under varying light intensities, temperatures, and day lengths. This comprehensive framework provides valuable insights into the metabolic behavior and cellular dynamics of microalgae, enabling spatiotemporal analysis for optimizing industrial processes. This work can support further advancements in the field and provide valuable insights that can pave the way for the accelerated growth and sustainability of the microalgae-based industry.

The European energy system is increasingly incorporating renewable energies as a result of the wind power market's exponential rise. However, from a life cycle standpoint, there still exists certain issues with wind turbines, especially in end-of-life management. In this study, an overview of the current state of a wind turbine's end-of-life management is provided. Turbines’ end-of-life management practices are a difficult endeavor for completing materials loops. The current state of play demonstrates that some materials used in wind turbines are still diverted towards energy recovery or landfills rather than more virtuous management such as recycling, remanufacturing or reuse, which hinder the recyclability and thus circularity of wind turbines. Blades, rare earth elements used in permanent magnets, and critical raw materials used in alloyed components are preventing wind turbines from achieving high recyclability. The remaining difficulties to improve recycling and close the material loop for wind turbines are then highlighted.

Social innovations in the energy sector (SEI) play an important role in the energy transition. This paper contributes to a comprehensive understanding of how SEI members use electricity, examining daily electricity consumption combined with contextual information from questionnaires for 65 users of a cooperative and a crowdfunding platform in Portugal. The research, based on an analysis of seasonal profiles of hourly data over a year using clustering techniques, allows the identification of five continuous and different behaviour patterns in each case study, four of them common. The results indicate that there are factors that determine each segment, especially the type of electrical service contracted, the heating/cooling systems available, the presence of storage systems and the characteristics of temperature control habits. All users had previously applied some measure of energy efficiency, suggesting a commitment to energy efficiency practices and environmental concerns.

Attention has in recent years shifted towards the environmental impact of human activities and the need to reach zero net carbon impact, including in the healthcare sector, being essential to review management processes to ensure their environmental sustainability. This study aims to evaluate the efficiency of environmental sustainability measures of institutions providing healthcare in Portugal’s National Health Service associated with water, energy, and waste management. A cross-sectional study was implemented in 24 institutions, with application of a Stochastic Frontier Analysis. The significant model for electricity showed photovoltaic panels to be an efficient measure, whereas LED lamps, solar panels and CO2 emissions quantification showed an association with inefficiency, with potential for investment. While the model for water consumption was not significant, water reuse and pre-treatment showed to be adequate. For total waste production, the model highlighted the relevance of green purchase and adequate waste management. When disaggregating for group IV waste, the model showed technical inefficiency of measures despite not being significant. While there are differences between primary and secondary care, there is margin for efficiency improvement, especially regarding energy and waste management, working with health managers and partners. Further research is needed to strengthen environmental policy changes.

The Portuguese government, as part of the 22nd Conference of the Parties (COP22) of the United Nations Framework Convention on Climate Change (UNFCCC) in 2016, has committed to ensure net zero greenhouse gas (GHG) emissions by the end of 2050 as a way of complying with the Paris Agreement. For that purpose, the Portuguese government approved a set of essential documents that stand as a guide for national organizations. Complying to that, the Portuguese Air Force Chief-of-Staff identified sustainability as key in the strategy for 2022/24, giving way to the development of the Air Force roadmap for carbon neutrality in 2050 (RCN2050PrtAF), which is divided in three main phases—Mapping, Reduction and Neutrality. Each of these phases included several tasks like estimation of the de GHG emissions and the carbon sequestration capacity (mapping phase) and then definition of the reductions needed, the priorities of action, the possible scenarios of reduction, and the key indicators to monitor the evolution and achievement of the goal—net zero emissions—(reduction and neutrality phases).

Mixed matrix membranes (MMM) combine the flexibility of polymers and the strength and durability presented by inorganic solids. In an economically point of view, the advantages of membrane separation are low capital investment and space requirements, high process flexibility and lower energy consumption, helping for a more cost-effective separation process and providing a high separation degree. The molecular sieves based on nano-sized silicoaluminophosphates (SAPO) appear as one of the main materials in MMM for gas separation because the pore size of chabazite (CHA) (0.38 nm) is near the kinetic diameter of gases like H2 (0.29 nm), CO2 (0.33 nm), N2 (0.36 nm), CO (0.37 nm), CH4 (0.38 nm) and reduced crystal size improves the dispersion and decreases interfacial defects. Doping SAPO-34 are intended to increase the potential of these solids. The use of isomorphic substitution by transition metals (Fe, Ni, Co, Mn), results in materials with different acidity that differ from the original SAPO in interactions with other compounds. Besides, the addition of ionic liquids (IL) or Deep Eutectic Solvents (DES) with high affinity and selectivity to CO2, onto the particle surface and then dispersing it in a polymer membrane can enhance the separation characteristics, resulting in better permeation and selectivity properties.

This study intends to explore the impact of tourism on air pollution at a regional level in Italy, and also to investigate the evidence of a tourism-induced Environmental Kuznets Curve (EKC) for Italian regions, including variables as an economic indicator (GDP), the energy consumption, and the number of nights spent at tourist accommodation establishments from both residents and foreign tourists. Most of the studies found in the literature investigate this relationship on a national scale, while this research focuses on a regional basis. The analysis is conducted using a set of three air pollutants (NOx, PM10, and PM2.5—the most critical in terms of air quality), over two different periods for comparison purposes: 2000–2008 and 2009–2018. The Levin-Lin-Chu unit root test proves the variables to be stationary, while the Pedroni cointegration test shows that they are integrated. A common main econometric model is employed to check the relationship among the variables: the Pooled OLS Estimator; the Granger panel causality test is conducted to see the causality among them. The tourism-induced EKC hypothesis is not validated, even if the findings show a decreasing relationship between economic growth and environmental pollution. Results also show slightly few differences between the two analyzed periods.

Climate change (CC) is one of the most significant threats to human well-being—affecting all countries, including Saudi Arabia. Addressing CC requires efforts from both the public and government, and understanding people's CC awareness is critical for devising effective policies to mitigate CC risks. This study is aimed at determining people's CC knowledge and awareness. A cross-sectional survey was conducted in Dammam and involved 310 people who consented to participate. A pretested questionnaire was distributed to collect data about CC. Only a few respondents were aware of CC causes and effects (14%). The significant CC causes identified were deforestation (28.1%), population growth (24.2%), urbanization (18.7%), vehicles (17.7%), and greenhouse gases (11.3%). Most of the respondents were very concerned about CC issues (67%) but (78.4%) had poor knowledge of the Sustainable Development Goals related to CC. Overall, the respondents had moderate knowledge of CC, indicating the need for an effective targeted strategy with a comprehensive action plan for a larger population to reduce the impact of CC.

In Mediterranean Europe, one of the expected consequences of climate change is the intensification of wildfire events. Given the importance of forests in helping regulate climate and the many ecosystem services they provide, it is crucial to identify how wildfires might impact them. In this context, the present work aims to identify the wildfire impacts caused to the ecosystem services in Portugal. This is done through a survey directed to Portuguese fire experts. Using The Economics of Ecosystems and Biodiversity (TEEB) definitions, experts were asked to share their perceptions on the fire impacts to forest ecosystem services in the short and long-term and indicate which services they feel require more policies to mitigate the impacts. The results showed that all ecosystem services are impacted to various degrees and different lengths of time. Regulating services were overall the most affected group and the most in need of specific policies. This study helped identify fire impacts, policy needs, and priorities in the perception of the experts in Portugal, which is valuable for guiding future research in various knowledge fields, especially related to raising awareness about behavioral adaptation to prevent and mitigate wildfire impacts in a changing climate.

The evaluation of different catalysts performance for the degradation of effluents from pharmaceutical and agrochemical industries was performed. The response surface method was used to specify the optimum values of operating parameters (e.g., pH and flow rate). The optimum operating parameters were pH = 6.8 and flow rate = 108.6 mL/min for pharmaceutical wastewater, whereas the pH and flow rate values of 6.5 and 108.6 mL/min, respectively achieved the highest degradation efficiency for agrochemical wastewater using a composite of carbon nanotubes (CNTs) and lanthanum vanadate (LaVO4). The mineralization rates of pharmaceutical wastewater were 89.5, 84, 74, 69.8 and 60.5% under five succeeding runs using CNTs/LaVO4, whereas the total organic carbon (TOC) removal efficiencies of agrochemical wastewater were 94.3, 93.1, 85.8, 76.2 and 73.2% in the five following runs. The degradation rates were 0.0114, 0.0156 and 0.0084 min−1 using a composite of Matériaux de l′Institut Lavoisier metal organic framework-53 (MIL-53(Al)) and zinc oxide (ZnO) (MIL-53(Al)/ZnO), CNTs/LaVO4 and pristine titanium dioxide (TiO2), respectively in the case of pharmaceutical wastewater, whereas the degradation rates were 0.017, 0.0196 and 0.0104 min−1 using MIL-53(Al)/ZnO, CNTs/LaVO4 and pure TiO2, respectively in the case of agrochemical wastewater.

In this study, nitrogen removal analyses of ammonium, nitrite and nitrate, as well monitorization of dissolved oxygen (DO), at different phases of a sequencing batch process, were carried out to investigate the process of nitrification–denitrification on a synthetic dairy wastewater. Total nitrogen (TN) removal efficiency increased with each cycle with 84.2%, 89.1%, 90.9% and 92.3%, for day 1, 2, 3 and 4, respectively. Most of the nitrogen removed occurred due to assimilation during cell growth. Ammonium, nitrite, nitrate at the end of cycle 4 showed significant variation when compared with cycle 1, with 41.4%, 78.6% and 70.4% reduction, respectively. This work allows to conclude that SBR is an effective method of reducing the nitrogen content of dairy wastewater.

Polyethylene terephthalate (PET), a major plastic waste, was recycled into solid carbon by thermal decomposition under autogenic pressure. PET was carbonized at 500–1000 °C and the effect of temperature on the properties and yield of the synthesized carbons or char was studied and discussed using SEM, TEM, EDX, XRD, FTIR, and BET. The synthesized carbons (SC) exhibit a range of microporous to mesoporous structures with a pore volume and surface area ranging from 0.2029 to 0.0573 cm3 g−1 and 448.88 to 3.3 m2 g−1 respectively. SC was employed in the removal of methylene blue (MB) as a model dye and the effect of contact time was investigated. SC produced at 500 °C demonstrated the highest adsorption capacity of 77 mg g−1 due to its high surface area, porous structure, and surface functional groups.

The farmer extension activity was allowed to increase livestock productivity, like in dairy farmers. In the backyard and semi-intensive system of dairy cattle raising, the socio-economic identification of farmers was important for the success of the new technology adopted. Hence, the purpose of this study was to know the socio-economic background of the dairy farmer, included age, education level, raising cattle experience, and the number of cattle occupied was affected to the farmer interested in the extension activities related to adopt a mobile anaerobic digestion (AD) technology. The survey method with stratified random sampling was applied by involved 93 dairy farmers of Batu City, East Java, Indonesia. The depth interview for data collection and followed by multiple regression analysis. The socio-economic variables were significantly (p < 0.05) correlated to the interested in an extension activity. While the partial t-test showed that the age of farmer and education level were significantly (p < 0.05) on interest but farming experience and the number of cattle were not significantly (p > 0.05) to the interest of extension. The education level was a major role in the interested extension. Hence, the educational level could be the main consideration in the intervention of extension related to adopting the mobile AD technology.

Il-Magħluq ta’ Marsaskala is a small saline marshland in the south of Malta. It is characterized with brackish water hosting peculiar salt-tolerant marsh communities and protected species that include the Mediterranean killifish, Aphanius fasciatus. This Natura 2000 Special Area of Conservation (SAC) consists of two different types of Annex I (Council Directive 92/43/EEC) habitats which are Habitat 1150* and Habitat 1410. This study focuses on water quality characterization and its implications within this SAC. Monitoring of water quality and abundance of the killifish was carried out over a period of one year (November 2017—November 2018). Temperature, pH, and dissolved oxygen were taken on-site while phosphates and nitrates were analyzed in the laboratory. The fluctuations observed in the water quality parameters can be attributed to seasonal variations, and possibly to anthropogenic activities surrounding the study area. The water quality seems also to be affecting the killifish population since a total of 22 individuals were recorded during this study. The density of killifish is excessively low when compared to data collected from similar studies within the same study area in previous years.

Oil-hydraulic system drives are conventionally performed by constant-speed electric engines, and typically operate with constant displacement pumps as their central transmission element, and oversized pressures are limited by relief valves. On the other hand, in applications where different speeds of approach and work are needed, different flows can be obtained with regenerative circuits, flow control valves, servo pumps or by different pump operating speeds. Consequently, a higher energy consumption is imposed by the relief flow valve. These and other approaches have been a growing focus of study in industry and academia, due to their potential for substantial increases in energy efficiency and reduction of electrical energy consumption and CO2 emissions. This paper presents a study of the potential economic gains associated with the electric drive of mobile or industrial (static) hydraulic systems characterized by variable drive units. With this drive topology, the electrical consumption associated with the engine drive is compensated, increasing energy efficiency over conventional systems, while reducing industrial carbon emissions and pressures on the dead phases of the operating cycle.

For the common citizen electric vehicles are symbol of sustainability because of its high-energy efficiency. Nevertheless, other environmental factors should be attended and in this work the noise emission is considered together with energy for urban traffic average speed decisions. The research strategy, developed in theoretic field, is backgrounded by former studies that provided the relation between speed and energy both for electric and internal combustion vehicles. In addition, the noise reduction of electric vehicles is obtained from the revision of literature. The present study adapted and uniformed the referred information and developed representative equations. Using the ESdB criteria, that is the energy saved by decibel reduction as speed varies; a new nomogram is proposed that illustrates the importance of considering both noise and energy in urban traffic speed decisions. Theoretical simulations are presented considering different percentages of electric vehicles. These simulations allow conclusions on the effect of electric vehicles in urban traffic and on the optimum average speed to be considered as different percentages of electric vehicles are in service. The benefits of EV’s are only interesting when over 90% of urban vehicles are electrical and average speed is 50 km/h.

Rural farms are an important part of each country’s consumption and typically include traditional energy installations, which are relatively reliable but energy-intensive and energy inefficient. In rural farms, the implementation of the Smart Farm concept with renewable energy and integrated resource management technologies has been slower than in the domestic and industrial sectors. This work describes a solution that was developed and implemented in a rural farm in Portugal which shows a significant reduction in energy consumption from the electricity grid, and the corresponding reduction in CO2 emissions. The present work makes a technical description of the developed solution and a comparison with other published scientific case studies.

Energy Efficiency (EE) and Indoor Air Quality (IAQ) are mandatory features in the rehabilitation of historical buildings. Even though it is challenging to manage both sides, EE demands are fundamental to increasing buildings´ thermal comfort, and IAQ requirements are essential for improving occupants’ wellness. There are, however, several constraints that limit the intervention in complex buildings, such as the installation of mechanical ventilation systems in heritage structures. This paper presents a case study where radon risk communication has been considered as a remediation measure in a highly constrained building—classified as National Architectural Patrimony—and whose recent retrofit had focused on EE improvement. Due to the intervention, the lack of significant air renovation can harm IAQ, and therefore, increase indoor radon concentration, which is a known problem in the building under study. This paper aims to evaluate the impact of proper radon risk communication in the actions undertaken to mitigate radon risk exposure. Moreover, it puts forward a conceptual framework that manages manual ventilation actions through collaborative sensing. Results have shown that under constrained retrofitting conditions, the fine-tuning between natural ventilation actions and thermal comfort can be the key to ensuring the building EE.

Government of India launched the PAT scheme to improve the energy intensity of high energy consuming industries in India. The first PAT cycle ran from 2012–2013 to 2014–2015, and currently the country is implementing PAT-VI. Cement is one of the industries that has been a part of all the six PAT cycles. Although PAT-I and II had included large cement producers, they were dropped from the subsequent PAT cycles. The paper does an input-oriented DEA model to examine the efficiency scores of large cement firms that were a part of PAT-I and II, but not PAT-III and IV. Efficiency scores are first calculated using one energy input and two non-energy inputs, and then using only energy inputs for the years 2012–2013, 2016–2017, 2017–2018, and 2018–2019, where these years represent the first year of implementation of PAT Cycles-I, II, III and IV. Results show when all inputs are considered, more number of firms are on the frontier, exhibiting pure technical efficiency. But most of them are scale-inefficient. When purely energy efficiency scores are estimated, the number of firms on the frontier decline considerably for all the PAT years. The efficiency scores for top ten cement producers do improve over the various PAT cycles in the first model that can justify their exclusion from subsequent PAT cycles. But the low energy efficiency scores do not support the exclusion.

Large amounts of edible oils are discarded each day from various sources, principally from households. When disposed wrongly into the nature, they can reach the ground, reducing the absorption of nutrients from plants, the aquifers, making them unusable, and finally, water surfaces, affecting the aquatic systems. From a circular economy perspective, one essential condition is looking for alternatives to reuse the used cooking oil (UCO). The objective of this paper was to discuss the application of Geographical Information Systems (GIS) to map the renewable energy potential for three possible waste-to-energy potential paths: biodiesel, anaerobic digestion, and direct combustion for the city of Guayaquil. For the cases of biodiesel (a), methane (b), and direct combustion (c), maximum values of 95, 88, and 95 MJ/kg/person, respectively, were found. Finally, Tarqui parish has much higher values than Ximena and Pascuales. Given its potential, the collection should start from this parish as a pilot project.

The objective of this study was to characterize the solid wastes generated in 13 different restaurants in the city of Guayaquil, located in the province of Guayas, Ecuador, evaluating the potential of using the generated waste to produce energy through incineration in a power plant. Data was collected for a period of 7-days for five categories of restaurants going from 1 to 5 forks, which serve meals as their business models. A total of 817.30 kg of waste was collected from the 13 restaurants during the time-lapse of the study, and 19.57 kg of lixiviate, calculating a final solid waste of almost 800 kg. Important to mention that the 1 and 3 forks categories produce the most quantity of waste with 11.79 kg/day/r and 11.36 kg/day/r, and the unique variety the least with 5.87 kg/day/r). Food waste was the most representative percentage for all types, with the highest rates in mobile establishments. Further on, the most present inorganic waste was plastics, with percentages ranging from 6.70 to 9.30%. Data was extrapolated to the total number of restaurants for one year, yielding a possible production of 31 TJ of electricity, concluding an environmentally acceptable alternative.

Photovoltaics represents one of the key parts of the low carbon energy transition. The combination of producing electricity from photovoltaics and agriculture production is gaining momentum. Such combination, when set up correctly, brings synergy, i.e., much more than just electricity from a renewable source. Energy security and food security are in this new concept called agrivoltaics. The paper reviews current knowledge on agrivoltaic systems as a branch of decarbonisation, and decentralisation energy strategies. Agrivoltaics in general means a photovoltaic installation that improves the conditions for cultivated crops, or cattle breeding, while renewable electricity production is an integral part and both activities are operated together at the same time. Different countries are trying to implement agrivoltaics in their policy differently using the knowledge of (so far limited) pilot installations. Pilot installations demonstrate that levelized costs of electricity (LCOE) are higher than ground-mounted photovoltaics installations. However, this is generally without considering the additional benefits for crops. Agrivoltaics has many forms and types. It can be combined with permanent cultures like berries, apple farms or with conventional agriculture. LCOE will depend on the type of agrivoltaics because each type needs different constructions and percentages of overshading. Vertical agrivoltaic installations bring a new daily diagram curve in electricity production from photovoltaics, better fitting into the electricity consumption curve. Further research will focus on multiple impacts of agrivoltaics, connections between agrivoltaic electricity production and consumption and finding new synergies between electricity production and crops cultivation.

Nowadays, many countries suffer economic, social, and environmental problems due to the lack of proper final disposal systems for different types of residues, like municipal solid waste (MSW), agricultural waste (AG), and waste cooking oil (WCO). In this context, the controlled degradation of wastes through anaerobic digestion (AD) in the absence of oxygen with the help of different groups of bacteria offers a sustainable solution for otherwise unusable waste. The main objective of this study was to develop artisanal anaerobic biodigesters and water displacement gasometers, to measure the influence of waste cooking oil as co-substrate for the anaerobic co-digestion with four different types of waste: cow, pig, chicken, and food from restaurants. As demonstrated, waste cooking oil ameliorated the values of 75% of the types of garbage. This study also indicated that the biogas production was comparatively higher in the co-digested bottles than in the mono-digested bottles.

The current world's significant problems are due to the dependence on the consumption of environmentally harmful materials for obtaining electrical energy where the search for new generating sources of this resource is a necessity. For this reason, this research tries to provide a novel way of generating electricity by using the Pichia membranifaciens yeast as a fuel source through microbial reactors manufactured at scale with Zn and Cu electrodes. The Pichia membranifaciens yeast was molecularly identified with 99.47% identity, managing to generate current and voltage peaks of 2.782 ± 0.241 mA and 0.865 ± 0.351 V, respectively, with an optimal operating pH of 7.519 ± 0.102 on the 7 days, where the values of electrical conductivity increased to 75.92 ± 3.54 mS/cm. The maximum values of the PD were 5.4534 ± 0.251 W/cm2 at a CD of 361.71 mA/cm2 for a voltage of 0.807 V. This investigation gives high values compared to other experiments using different types of substrates and generating a new natural aggregate to increase electrical values without using chemical compounds harmful to nature.

Fossil fuels are increasingly limited in today’s world, causing an energy crisis due to external factors, increasing prices in international markets. To solve this global problem, the energy transition related to mobility in companies that oversee their car fleets is highlighted. This transition to electric mobility influences several economic, technical, and social aspects, thus it becomes crucial for companies to adapt their infrastructure and dynamics to have more sustainable practices. According to the 2021–2022 EIB Climate Survey, 55% of Portuguese young people consider climate change when looking for a job. Furthermore, when asked about future car purchases, 84% of Portuguese car buyers say they will purchase either a hybrid or electric car, making Portugal the EU No. 1 country in terms of intentions to purchase electric cars. These statistics show the urgency for companies to adapt to future needs, as well as align with the European goals of reducing greenhouse gases emissions to 45% by 2030 and to zero by 2050.

With the growing interest in using biomass as an alternative energy source, the scientific study of its behavior becomes even more relevant. Furthermore, the heterogeneous nature of biomass makes the process more challenging. A laboratory-scale traveling bed furnace was used to study the ignition of some ligneous biomass pellets, specifically the measurement of the ignition time of volatiles released by different types of wood pellets. The experimental ignition tests were carried out at five different corrected furnace temperatures, namely between 359 and 443 °C, and using the same mass flow rate of the supplied air. The results show that for the studied pellets, the ignition time is linear furnace temperature dependent; as expected, for all species, the pellets ignition time was higher at 443 °C. In general, it was verified that the pellets species presented some variableness in the ignition time, being the Pinus pinaster the specie that obtained a higher ignition time.

This work aimed to evaluate the conversion potential of maize stover (MS) from phytoremediation of heavy metals contaminated soil to bioethanol. Thus, MS was submitted to an acid pretreatment with 3% (v/v) H2SO4, HCl, HNO3 or CH3COOH at 85 °C for 48 h. An enzymatic hydrolysis step with Accellerase or Ultraflo was applied at 50 °C for 13 h. Finally, Saccharomyces cerevisiae was used to ferment the glucose at 37 °C, followed by distillation to recover ethanol. The average yield in ethanol for the MS produced in the two contaminated soils was 0.51 and 0.32 gethanol/gMS for the MS treated with HCl and Accellerase and 0.39 and 0.27 gethanol/gMS for the MS treated with HNO3 and Ultraflo, respectively. For the MS produced in the control soil, the yield was 0.37 and 0.44 gethanol/gMS for the treatment with HNO3 and Ultraflo and HCl and Accellerase, respectively, being the differences in ethanol yield assigned to the different cellulose/hemicellulose content of the MS samples. No metals were detected in the ethanol recovered. This research demonstrated the feasibility of valorization of MS from heavy metals contaminated soil phytoremediation through ethanol production, contributing to a more sustainable process of soil phytoremediation.

Due to the great changes that the environment is undergoing due to the excessive use of fuels to obtain electrical energy, in the search for new ways to generate this type of energy, this research gives in a new way the use of Candida boidinii yeast as fuel for the generation of electricity through MFC at laboratory scale. Managing to generate maximum values of electric current and voltage of 3.3904 ± 0.0916 mA and 0.70342 ± 0.04726 V, whose values were obtained at a pH of ~6.5848 ± 0.2174 and with a value of 63.701 ± 0.911 mS/cm of electrical conductivity. The cells managed to generate a maximum power density of 7.839 ± 0.159 W/cm2 whose current density was 449.657 mA/cm2. Finally, the cells were connected in series, managing to turn on a green LED, thus demonstrating its effectiveness in the generation of bioelectricity.

The wine distillery wastewater, called wine vinasse, is an aqueous by-product of wine distillation containing the non-volatile fraction of the distilled wine and other organic waste material. The wine distillation industry generates a high volume of wastewater (10–20 L per liter of produced ethanol). This wastewater is characterized by its low pH values and high organic matter concentration. This work studies the effect of mechanical mixing of an anaerobic digester reactor to produce biogas from wine vinasse wastewater in batch operation. When a mechanical mixing system at 8 rpm was employed, biogas volume increased by 20.6% and methane volume by 21.9%, evidencing the better performance under continuous mixing of the anaerobic reactor. The batch assay reached a specific methane production of 1.03 NL CH4/g-VS. The wastewater treatment shows a COD removal efficiency of about 90%. The kinetic evaluation confirmed the experimental results as the assay with the mixing system did not describe a lag phase contrary to the system without mixing. The biogas produced during the anaerobic digestion process can be converted into electrical energy or used as an energy source in the distillation process (reducing its environmental impact), with a power of 2.54 kWh/kg-VS and 8.26 kWh/kg-VS, respectively.

The potato chip is an important and widespread food industry that generates large quantities of organic residues, which can be valorized through energy recovery. This work aims to assess methane yield obtained through the anaerobic digestion of potato peel (PP) and compare the energy recovered with alternative processes such as ethanolic fermentation, and pyrolysis. Anaerobic digestion assays were performed to determine the biochemical methane potential of potato peel. A maximum of 177 ± 39 L CH4/kg (on a volatile solid basis—VS) was attained while the modeling through a first-kinetic order indicated 187 L CH4/kg. Considering the experimental value (177 L CH4/kg VS), the anaerobic digestion allows for generating 6.2 MJ/kg of PP (dry basis). Theoretically, anaerobic digestion seems to present a higher energy recovery than ethanolic fermentation and pyrolysis. Overall, 7.6 × 103 GJ/year can be recovered through anaerobic digestion of PP produced by a potato chip industry with a production capacity of 26.3 kton/year.

As a promising tool in converting waste to energy, anaerobic digestion (AD) was utilized in this study. Two experiments were performed by (1) co-digestion of press mud (PM), and molasses-based distillery wastewater (DWW) and (2) immobilized AD of DWW. Experiment 1 was done with variation of volume of DWW, PM and tap water. The highest methane yield was 61.3% and 78.23% for PM mixed with DWW, with or without added nutrients, respectively. With added nutrients, a 300:600 (DWW to PM) ratio produced the highest methane content. Experiment 2 was carried out in a thermophilic 2-L Erlenmeyer flask inside an orbital shaker using a K1 moving bed biofilm carriers to immobilize DWW with addition of nutrients and glucose. Batch 5 had a BOD/COD ratio of 0.23, yielding the highest volume of 2-L in 1 day. Since there was a niche for bacterial growth, DWW mixed with nutrients, glucose, and media performed the best in terms of biodegradability. Both setups include a homogenous feed had negligible amount of methane due to the less carbon present. The results demonstrated that added nutrients can improve AD efficiency using plastic carriers with immobilization and increasing volume of the substrates.

The bioenergy production from alternative sources such as biomass has been leading to an increase of biomass fly ash (BFA) that need proper management. In this study, the performance and optimization of the biochemical methane potential of tomato residues were studied through the addition of BFA. The results demonstrated that higher methane production can be achieved when BFA is added in the concentration of 2500 and 10,000 mg/L instead of the use of a synthetic nutrient medium. The optimization of the substrate-to-inoculum ratio (SIR) and the BFA concentration demonstrated that a higher SIR can be applied in the reactor due to the higher buffering capacity of the system, which allows the digestion of higher substrate quantities. The optimum conditions determined were a SIR equal to 1.0 and a BFA concentration of 5000 mg/L. Moreover, the kinetic study revealed that the BFA can be added to the anaerobic digestion process without compromising the rate of biogas formation. Overall, this study demonstrated that biomass fly ash can act as a buffering agent as well as a nutrient supplier in the anaerobic digestion process.

Batteries from electric vehicles can still provide around 80% of initial capacity, being suitable for stationary applications. Electricity storage is a solution for integrating renewable energies, as the electrification of the transportation fleet will make used batteries available. However, it is unclear if second-life batteries (SLB) will offer a more sustainable alternative to stationary new batteries (SNB). Therefore, this study investigates the life cycle economic impacts of future SLB in Flanders, Belgium. It focuses on collecting, dismantling, repurposing, using them in a second application, and recycling those batteries. Hence, a levelized cost of storage (LCOS) calculation is carried out from cradle-to-grave. Three use cases are assessed: (a) a residential use case, (b) an industrial use case, and (c) a utility use case. Cost data represent the geographical scope of Flanders, Belgium. The calculated LCOS of SNB for the three use cases were found to be between 71.77 €/MWh and 202.25 €/MWh in 2040, whereas the LCOS of SLB vary between 64.99 €/MWh and 211.10 €/MWh. For SLB, dismantling and repurposing costs dominate the first years economically. Towards 2040 battery purchase and charging costs will be major contributors. Overall, the utility use case proposes the lowest LCOS. The cost-competitiveness amongst SLB and SNB varies over the different years. This study highlights the importance of the application. Furthermore, it stresses that the cost of extending the EV batteries lifetime can be considerable.

One of the major challenges for the European Union is to achieve climate neutrality by 2050. The European directives and action plans such as the Green Deal are preparing the economic sector for climate neutrality. The EU has improved its electricity and gas markets, moreover, has fomented energy efficiency, renewable energy deployment, reduction of greenhouse gas emissions and a stronger carbon price. This transition involves the decarbonization of the energy industry, and the energy economy sector leading to changes in the business models and the labour market. Adopting the principles of a circular economy allows for changing the current economic system into a more sustainable one. In this context, generating power through renewable sources, like wind, is a viable way to reach the energy transition. At the same time, the first wind farms are reaching their end of life. Therefore, this work analyses the economic aspects related to the end-of-life of wind farms based on a systematic literature review of life cycle assessments to verify the challenges and advantages. As observed, studies are required to equalize some issues such as reducing the co-dependency of raw materials and developing secondary markets to treat waste and components for reuse and repowering strategy.

In the new paradigm of smart grids, load flexibility remuneration strategies play a key role in defining innovative business models and market frameworks using distributed energy resources and demand response. This article establishes a set of use cases used to support the application of remuneration strategies considering contextual load flexibility. In other words, the various new tariffs and remuneration plans consider the context provided by solar and wind power, different times of the day and week, temperature, and electricity market prices. Also, depending on the circumstances, dynamically specified consumer clusters are envisaged for a realistic validation of results while also analysing higher smart grid efficiency, decreased pollutant emissions, and cheaper energy prices. The proposed use cases are proposed in the context of COLORS (COntextual LOad flexibility Remuneration Strategies), a project investigating business models and market frameworks with a particular emphasis on demand response.

There is a growing concern about global issues such as Global Warming. However, other problems concerning air emission pollutants such as sulphur dioxide, particles, and heavy metals are also of great importance, since they are responsible for many health and sustainability problems. Various energy studies give much relevance to greenhouse gas emissions (GEE) leaving behind the other air pollutants. In this work, several scenarios for the year of 2020 were considered and for each one the air pollutants emissions were estimated. It was possible to conclude that if all fossil fuels were replaced by natural gas there would be a significant reduction in all pollutants except CO and non-methane volatile organic compounds (NMVOC). Heavy metals would present a reduction of almost 100%. The other scenarios considered the replacement of fossil fuels, the solid ones first, then liquid and finally natural gas with photovoltaic and/or wind technology. As expected, reduction obtained for total renewables scenarios was of 100% for all pollutants except for CO2 that presented reductions between 90 and 100% (only wind). It would have been avoided the emission of 240 Mt of GEE and 2.32 Mt of other pollutants which is rather important considering the global warming and health problems they caused.

This study compared the financial performance of renewable energy companies. The study focused on 2019–2021 data from the top ten companies in the S&P Global Clean Energy Index. The research model consisted of the current ratio, quick ratio, accounts receivables turnover, asset turnover, stock turnover, liability ratio, debt to equity ratio, fixed assets to constant capital ratio, return on assets, and return on equity. The data were analysed using the Best Worst Method (BWM)-based TOPSIS method. The financial ratio group with the highest weight in the renewable energy sector is the profitability ratio (42%). There is no significant change in the annual performance ranking of the companies.

The main goal of this article is to identify and to discuss the significant potential of the Iberian countries to EU decarbonization strategy and security of supply, due to their natural gas infrastructures and green hydrogen (H2) projects implementation. In line with the renewable energy sources (RES) expansion, H2 has emerged as a promising energy source. Notwithstanding, there are still major economic and technological constraints that can explain why H2 represents only 2% of the European energy consumption. Energy transition costs are widely recognized as a major constraint, while security of supply also remains a strategic driver. Among others, the inclusion of a low percentage (10–15%) of green H2 in natural gas grid appears to be a reliable contribution to the European decarbonization process while allowing for an economically consistent strategy along time.

The fuel and energy complex occupies one of the leading roles in the world economy, ensuring the dynamics and quality of economic growth in commodity-producing countries. At present, achieving high growth rates can create serious environmental problems, since the use of energy sources causes significant damage to the environment and determines climate change. In the work, the authors established the relationship between energy consumption and some factors for 89 countries, which are divided into seven macro regions. It was possible to determine the impact of consumption of oil, gas, coal and alternative energy sources, as well as the population, economic structure and energy intensity of macro regions on total energy consumption. The calculations confirm the fact that many countries have begun the transition to the use of alternative energy sources, namely: the countries of North America, Europe, South and Central America and the Asia–Pacific region. However, the proportions of the energy transition are significantly different.

This study examines the impact of oil price fluctuations (OP) on Timor-Leste's macroeconomic variables, i.e., the consumer price index (CPI), the exchange rate (ER), gross domestic product (GDP), the interest rate (IR), and money supply (M2). We used monthly data from 2003 to 2019 and the vector autoregressive (VAR) model. This study confirms that oil price fluctuations are associated with a significant positive and negative effect on the exchange rate and have a significant positive effect only in the second period, while the effects of the other variables are not statistically significant. The impulse response function results show that: (i) a positive OP fluctuation leads to an increase in CPI; (ii) a favorable OP reduces GDP in the short run and increases it in the long run; (iii) an OP fluctuation has a positive effect on ER; and (iv) a positive (negative) OP fluctuation affects the interest rate in different periods. Moreover, a negative OP fluctuation affects M2 in the short run, while a positive OP fluctuation affects M2 in the long run. The empirical results of the Granger causality tests show bidirectional causality between ER and CPI.

The present study applies time-series volatility models to study oil price volatility and the effect of macroeconomic variables, such as the Gross Domestic Product (GDP), Consumer Price Index (CPI), interest rate, exchange rates, and money supply on the economic growth of Timor-Leste during 2003M01-2019M12, as well as the reverse effect of GDP growth over oil prices. Considering the Autoregressive Conditional Heteroskedasticity ARCH (1) and the Generalized GARCH (1,1) models for the oil price volatility, results show that the interest rate can lower the oil price. Contrarily, the CPI, exchange rate, GDP, and money supply increase oil prices. Meanwhile, the CPI, exchange rate, and interest rate drive negatively GDP, reducing economic growth. Thus, oil prices and the money supply could influence Timor-Leste's economic growth. Exponential EGARCH (1,1) estimation of the oil price shows that interest rates could depress the oil price. Symmetrical and asymmetrical techniques have shown that oil prices and economic growth in the Timor-Leste region are volatile. This study is important for Timor-Leste policymakers to consider the impact of oil price volatility and macroeconomic variables to be significant to economic growth and prevent their negative effects.

Millions of tons of polluted personal protective equipment, such as face masks, face shields, and gloves related to the COVID-19 disease, are becoming dangerous infectious waste. Suppose PPE is littered in the open environment, whether aquatic or terrestrial. It will most likely produce the blockage of sewages in towns and cities and could also percolate to water vessels and prevent the aeration of agricultural land. Hence, the quantification, geospatial spreading, and thermochemical valorization of personal protective equipment waste were performed for the city of Guayaquil. The overall daily face masks, pairs of gloves, and face protectors waste generation in the town reach 816,673.25 masks, 43,173.34 glove pairs, and 29,148.88 face protectors. Considering that the standard weight of one mask is 5 g on average, this number of face masks turns into approximately four tons of waste daily (1.5 thousand tons yearly). Three-ply surgical disposal (3PFM) is the most wasted for face masks, accounting for 52.31%, followed by KN/FPP masks with 15.36%. 3PFM is primarily wasted in El Fortin, La Florida, Trinitaria, and Guasmo neighborhoods, all urban-marginal of the city. Finally, when talking about final disposition, incineration is preferred over landfilling. Given that the vast majority of thermal electricity production plants are based on the combustion of fuels, whether liquid or solid, this is the most immediate solution for the PPE waste problem.

Malawi's low electrification rate (18%) is pitiful, given the country's abundant energy resources. Several barriers to renewable energy installation were identified through a review of the literature. The barriers were classified as sociocultural, economic, market, technical, environmental, ecological, and geographical, as well as political-governmental barriers. The barriers were further discussed with some government and non-governmental organizations initiatives to overcome them. The study also discussed proposed solutions to the barriers and suggested further research into these issues. Thus, if the solutions are implemented substantially, the country's access to electricity will improve. Globally, Malawi will also be a part of the worldwide trend toward the use of renewables and the fight against climate change and global warming caused by greenhouse gas emissions.

The purpose of this study was to explore, through the semi-structured survey technique, the perception of LPG gas consumption for domestic use in the canton of Guayaquil–Ecuador, with high rates of non-renewable energy consumption. Through a bibliographic study and relying on urban sustainability and the data obtained from the ministries of energy and statistics of Ecuador, the relationships between the increase in domestic gas consumption, its effect on the country's economy and on the urbanization process. In the discussion of the results, we indicate that the families of the Guayaquil canton perceive that the highest energy cost is found in the electricity sector; the dominant energy option (use of fossil energy) with many negative effects on society and the environment.

The Energy Literacy Scale (ELS) was created to assess students’ energy-related knowledge and awareness of the implications of energy production and consumption, everyday energy use, and the adoption of energy-saving behaviors. The energy literacy scale was drafted and pilot tested among elementary school students across Kerala, India. Initial exploration of the measure yielded promising results: Cronbach's reliability coefficients for cognitive, emotional, and behavioral subscales varied from 0.68 to 0.78, while average discrimination indices ranged from 0.28 to 0.43. Factor Analysis was used to select appropriate questions for the Energy Literacy Scale with due importance being given to each of the Knowledge, Attitudinal and Behavioral domains. The field-tested ELS includes three knowledge factors namely (1) Energy sources, Efficiency and Conservation, (2) Energy Use and Implications and (3) Basic Energy Concepts. Three behaviour and two attitude dimension sub-scales are included in the accepted instrument. The ELS is particularly useful for determining the baseline energy literacy skills of potential responders and evaluating the broader effects of educational initiatives.

The Energy performance certificates (EPCs) are an integral part of the Energy Performance of Buildings Directive (EPBD) and should have an essential role in enhancing the energy performance of buildings. For this reason, further improvements to EPCs might be necessary. Nowadays, contractors can refurbish building envelopes without providing environmental benefits. This paper emphasizes the need to track the environmental issues previously and during the rehabilitation of buildings envelopes. Due to the low heating practices of Portuguese families, in many cases, building materials’ embodied energy may surpass the active energy demand for heating and cooling in a cost–benefit analysis. Some measures, like high insulation thicknesses and top-performance windows, may generate similar or even higher embodied energy than the potential reductions during operation. Hence, paradoxically, the global energy and Green House Gas (GHG) emissions might increase to reach Nearly Zero Energy Buildings (NZEBs), as the embodied energy will increase using higher insulation thicknesses. A new approach should provide a sustainable and more reliable service to end-users, informing them about the environmental impacts in the whole life cycle, including the embodied energy of the building envelopes components like thermal insulation systems and windows.

Uncontrolled open dumping and burning of municipality solid waste (MSW) has resulted in soil, water, and air pollution in many urban cities in India. Landfills are the most common cost-effective solution for MSW management in many developing countries like India. However, the identification of suitable landfill sites always remains a challenging task as it involves selection of several environmental criteria set by the local authorities. The objective of this study is to identify the most potential landfill sites proposed by the Government in Bengaluru Metropolitan Region, Karnataka state, India using Geographic Information System enabled Analytical Hierarchy Process based multi-criteria evaluation technique. Several criteria and constraints as recommended by the local authorities along with the proximity to the solid waste processing plants are used to identify the potential landfill sites in the study region. The study identified three highly suitable sites (Neraluru, Gudhatti, Madivala) for landfills which are not only environmentally sustainable but also economically attractive as they are closer to the solid waste processing plants minimizing the transportation cost involved in the disposal of solid waste from the source to the final disposal sites in the study region.

The economic growth of the countries is mainly associated with either the introduction of new technologies or involvement of the extra resources into production. However, industrial activities are still based on the combustion of fossil fuels, which poses implications for the climate change. Russia has been one of the five largest emitters of greenhouse gases for the past decade. Therefore, the achievement of carbon neutrality should be accompanied by the transition to the trajectory of sustainable development. This research considers the calculation of the greenhouse gas emission in the energy sector carried out on the basis of the guidelines of the Ministry of Natural Resources and Ecology of Russia, which was compiled on the basis of the IPCC methodology. The results showed that there is a general decrease in carbon dioxide emissions from stationary sources of fuel combustion in Russia, and the main source of emissions is combustions of fossil fuels in boilers and furnaces. The reduction of the emission in the Urals and Siberian Federal Districts is the result of the gasification process. However, despite the favorable trend, it is advisable to pursue an active climate regulation policy in these regions. Policy should pay attention to reducing emissions from coal, gasoline, diesel fuel and other petroleum products, which are the main sources of the greenhouse gases in these regions.