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Amidst the surging energy demand, contemporary biofuel production and distribution systems face the challenge of being sustainable, resilient, and responsive to mitigate environmental impact, withstand disruption, and meet regulatory requirements while remaining competitive in the market. However, existing literature predominantly focuses on sustainability alone, leaving a research gap in understanding the complex relationship among sustainability, resilience, and responsiveness within biofuel production systems. This study aims to bridge this gap by proposing a novel approach that integrates sustainability, resilience, and responsiveness within the (lean, agile, responsive, green) LARG framework through the development of a decision-making system. To mitigate operational uncertainty in decision-making, the study employs neutrosophic fuzzy optimization (NFO), support vector regression (SVR) for biomass supply prediction, and geographic information systems (GIS) for potential biorefinery site identification. The proposed model and solution approach undergo validation in a real case study, accompanied by sensitivity analyses. Key findings reveal a substantial influence of the decision maker's risk attitude on strategic decisions in the biofuel production system, with risk-averse approaches resulting in lower objective attainment levels. Additionally, strategic decisions concerning biorefinery locations emerge as critical factors in the biofuel production and distribution system, significantly affecting both upstream and downstream operations and the attainment levels of sustainability, resilience, and responsiveness dimensions. Furthermore, the study observes that introducing redundancy to the biodiesel production network without adequate planning may not necessarily enhance resilience. However, reinforcing critical nodes with redundancy proves to be a significant factor in improving overall network resilience, hence withstanding disruptive events. Biofuel producers, along with policymakers, regulatory bodies, and related stakeholders, stand to potentially benefit from this research. • Developing a Sustainable, Resilient, and Responsive Biodiesel production system. • Enhancing system resilience with lateral supplies and node analysis metrics. • Applying SVR for biomass forecasting and GIS for the analysis of spatial data. • Proposing a modified neutrosophic fuzzy approach to deal with uncertainty. [ABSTRACT FROM AUTHOR]

• Different geothermal technology and their advancement are summarized. • The environmental impact of different geothermal technology is presented. • The advantages and disadvantages of the technology are presented. • The opportunities for improvement the geothermal technology are explored. • The potential role of the geothermal technology in the sustainable future is discussed. Rapid population growth as well as modern technology reliance lead to a greater demand for energy consumption. An ever growing focus on creating sustainable environment requires energy sources to be used with caution. Two effective solutions to address these concerns include utilizing renewable energy resources and increasing efficiencies of current technologies. Geothermal energy provides a renewable energy source that has potential to supply reasonable amounts of electricity, heating, and cooling. The present research elaborates upon methods of harnessing energy using various geothermal technologies. Various methods of performance improvement, as well as integration of geothermal technology with other renewable energy sources are also discussed. The environmental impact and economic viability of the technology are mapped as well. The advantages and disadvantages of the technology and opportunities for improvement are explored based on the recent studies. Briefly, the potential role of geothermal technology in a sustainable future is discussed in the study. Finally, the prospective topics of future research are presented for further investigation. [ABSTRACT FROM AUTHOR]

Faced with international climate obligations and domestic pressure, Singapore has recently raised its climate goals significantly. The government had affirmed its intention for carbon emissions to peak before 2030 and for Singapore to attain net zero greenhouse gas emissions by 2050. However, as Singapore transitions to green energy, there remains much uncertainty if this transformation, coupled with rapidly evolving geopolitics, would present vulnerabilities to energy security. Hence, this paper is an attempt to investigate Singapore's possible paths to achieve these goals while enhancing energy security in view of present and future energy plans. Key parameters of energy security in Singapore's context are identified to determine how different policy decisions would influence them. The effects of various current and potential policies can thus be evaluated using a systems thinking and system dynamics approach to propose new energy solutions to improve energy security. System dynamics modelling reveals that new energy supply solutions would have to be considered in Singapore's Energy 2050 Plan while furthering efforts in reducing energy demand. Findings reveal that Singapore should have a target of >80% renewable energy by 2050, pursue a central strategy towards sustainable diversification of its energy sources into hydrogen, electricity imports and solar energy and reduce energy consumption. Accordingly, Singapore's energy security can then be improved in terms of the economic, energy supply chain and environmental dimensions, and towards attaining net-zero emissions. [Display omitted] • Systems approach to Singapore Green Plan 2030 and simulation of policies towards energy security and net zero. • Systems thinking and system dynamics modeling to evaluate key assumptions and energy security parameters. • Model validation, both structural and behavioral, through base model simulations as well as behavioral tests. • Effect of government policies on hydrogen energy, low carbon electricity imports and energy saving on energy security. • Simulations suggest policies for higher renewable energy targets to attain net zero carbon emissions and energy security. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Upcycling of surplus hydrogen streams. • Integration of recovered hydrogen into a hydrogen supply chain. • Techno-economic feasibility of hydrogen upcycling using optimization-modelling. • Surplus hydrogen has a pivotal role in initiating the shift to a hydrogen economy. Abstract To further advance a world powered by hydrogen, it is essential to take advantage of the environmental benefits of using surplus industrial hydrogen to energy conversion. In this paper, the integration of this renewable source in a hydrogen supply chain has been analysed with the following considerations, (1) the techno-economic modeling is applied over the 2020–2050 period, at a regional scale comprising the north of Spain, covering the main sources of surplus hydrogen in the region, (2) the supply chain feeds fuel cell devices powering stationary and mobile applications and, thereby stablishing the quality standards for the upcycled hydrogen and, (3) a mixed-integer programming model (MILP) is formulated to predict the optimal integration of surplus hydrogen. The advantages of this research are twofold, (i) on the one hand, it provides the methodology for the optimal use of surplus hydrogen gases promoting the shift to a Circular Economy and, (ii) on the other hand, it contributes to the penetration of renewable energies in the form of low cost fuel cell devices to power stationary and mobile applications. The results show that the combination of all the infrastructure elements into the mathematical formulation yields optimal solutions with a plan for the gradual infrastructure investments over time required for the transition towards a sustainable future energy mix that includes hydrogen. Thus, this work contributes to improving the environmental and economic sustainability of hydrogen supply chains of upcycling industrial surplus hydrogen. [ABSTRACT FROM AUTHOR]

Recently, approaches have been established to improve the grounding system performance, especially with the increasing numbers of large-scale solar (LSS) PV farms. Soil resistivity is one of the contributing factors to the inefficiency of power generation as it induces high impedance on electricity flow from the source to highly sensitive PV equipment and devices such as inverters. Some critical issues on nutrient leaching derived from ammonium sulphate fertilizer direct to ground soil are the focal point of this work with the fact that soil resistivity value is inversely proportional to increasing soil salt content. Therefore, a low grounding system could be obtained with a high Electrical Conductivity (EC) and high soil moisture content. In this work, a conceptual setup for an agrivoltaic condition with 500 units of herbal crops has been cultivated directly underneath 1 PV string in Puchong Solar Farm, Selangor, Malaysia. The amount of salt or nutrient under this condition was measured leaching approximately 40 mL per polybag as means of ground treatment to improve soil resistivity value, thus indirectly reducing the risk of electrical damage. The agrivoltaic approach has shown that it can improve the performance of a grounding system in an LSS PV farm with a significant reduction of 4.45 Ω earth resistance on average. • Integrating agrivoltaics to improve grounding in large-scale solar PV farms. • Nutrient leaching as ground treatment for reducing soil resistivity. • Cultivation of herbal crops under PV panels in Malaysia's Puchong Solar Farm. • Leaching measured at 40 mL per polybag to enhance soil resistivity. • Significant 4.45 Ω average value in earth resistance reduction achieved. [ABSTRACT FROM AUTHOR]

This study presents groundbreaking advancements in sustainable power through a comprehensive exploration of double-stage segmented thermoelectric generators (DSSTEGs) optimized for efficient solar energy conversion. Specifically comparing DSSTEGs with other solar thermoelectric generator (STEG) configurations through geometry parametric optimization, we elucidate the intricate interplay between material properties and design parameters using a finite element method-driven numerical approach. The focus is on achieving 4E optimization (energy, exergy, environmental, and economic factors). Our results demonstrate that a skutterudite content of 6.17% maximizes DSSTEG performance, showcasing its superiority over conventional STEGs. The optimized DSSTEG excels with remarkable CO 2 savings of 23.78 kgyr−1 and an impressive high output power of 50.08 W at the optimal skutterudite content. Moreover, the DSSTEG design demonstrates a balanced cost-effectiveness with an outstanding $0.05 per watt output, surpassing conventional STEGs' cost-efficiency. These findings offer a pragmatic framework for integrating innovative materials and optimized designs in concentrated solar energy applications, signifying a significant stride in the field of thermoelectric generators. The pivotal role of materials and design in defining and optimizing performance for enhanced solar energy conversion is highlighted, propelling the path towards a more sustainable and efficient energy future. • Optimized DSSTEGs for efficient solar energy conversion. • Skutterudite content at 6.17% maximizes DSSTEG performance. • CO 2 savings of 23.78 kgyr−1 achieved with optimal parameters. • High output power of 50.08 W at optimal skutterudite content. • Balanced cost-effectiveness with $0.05 per watt output. [ABSTRACT FROM AUTHOR]

Energy trilemma is one of the most pressing concerns on agendas of many governments and international organizations. In this paper, the authors propose a novel quantitative tool to aid designing policies for energy systems planning and creating research and developments programs aimed at achieving specific policy goals. The proposed modified Markowitz theory can be used to build the efficient plane considering sustainability, security and affordability of the energy system composed of a portfolio of competing technologies. The novel and original contribution of this paper is the extension of the Markowitz theory to include the measure of portfolio’s sustainability and proposing a new tool to tackle the energy trilemma. The proposed tool was used to compare policy packages to support possible steady green growth of Singapore economy – a densely populated city state with no natural resources, dynamic economy requiring secured supply of energy, and ambitions of being a leader in sustainable development. It was found that efforts aimed at simultaneous improving performance and lowering costs of novel technologies is more desirable, contrary to policy focusing on either alone. Fuel cells and solar photovoltaic panels were found to be important pieces of an efficient power generation portfolio. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) power generation is critical to many climate policy goals, as PV electricity results in little or no greenhouse gas (GHG) emissions during use, utilities and governments view PV installations as a way to accelerate progress towards emissions reduction targets. However, typical analyses of the GHG implications of the PV lifecycle ignore inter-temporal effects, in which the initial GHGs emitted in PV manufacturing phase must be offset by avoided fossil-fuel combustion emissions during use. Thus, the overall climate benefits of PV are a function of both GHG efficiency of PV manufacture, and electricity generation efficiency of deployed modules during use. Improvements to PV manufacture result in immediate climate benefits, in contrast with improvements in module efficiency which may offset greater GHG emissions, albeit over decades of useful life. This study presents a novel framework using the cumulative radiative forcing (CRF) metric to demonstrate the significant climate benefit of improving PV manufacturing processes predominantly located in GHG-intensive geographies and determines the equivalent increase in module efficiency that provide the same climate benefit. The findings show low-carbon PV manufacturing increases the life-cycle climate benefit by 20% and is equivalent to increasing the module efficiency from a baseline value of 17% to 21.7% and 16% to 18.7% for mono-Si and multi-Si modules, respectively. With commercial module efficiency having increased annually by only 0.25% over the last 12 years, the implication is that improving PV manufacturing may be more effective than module efficiency improvements for increasing the climate benefit of terawatt scale PV installations. [ABSTRACT FROM AUTHOR]

This paper presents a quantitative assessment of Sustainable Energy Security (SES) of the energy demand sub-system for India by calculating a multidimensional SES index. The demand sub-system has been evaluated for four dimensions of SES, viz., Availability, Affordability, Efficiency and (Environmental) Acceptability using 23 selected metrics. A hierarchical structure has been used to construct indices using ‘scores’ (objective values of selected metrics), and ‘weights’ (subjective values, representing importance of each metric) which are then aggregated, to obtain a SES index. Various sectors of the energy demand sub-system are evaluated and dimensional and sectoral indices are calculated for the years 2002, 2007 and 2012. Assessment of the obtained energy indices is undertaken (separately for rural and urban residential sector) and results reveal that all (except one) sectoral indices have shown an increase during the period of assessment. The results show that from 2002 to 2012, the aggregate SES index has increased by approximately 10% which indicates a gradual improvement in the sustainability and security of the energy demand sub-system. However, the SES index is approximately 0.7 (against a desired target of 1.0), which implies that there is still a large scope for improvement in the performance of the India’s energy demand sub-system. A sensitivity analysis of various indices reveals that the SES index is relatively robust to variation in weights allotted to different dimensions and hence provides a reliable assessment of the energy demand sub-system. [ABSTRACT FROM AUTHOR]

[Display omitted] • A deeper understanding of energy consumption is entrenched. • Energy consumption scenarios are framed based on higher energy consuming sector. • Optimized energy policy in context with derived scenarios is proposed and elaborated. • Nexuses among energy accessibility, consumption, intensity, and RE penetration is established. • Energy consumption influenced sound energy policies are suggested to achieve SDG 7. The Sustainable Development Goal 7 (SDG 7, Affordable and Clean Energy) is the key to achieving climate goals and constructing effective policies have an immense role to foster the actions. The three major components of SDG 7 include energy accessibility, renewable penetration and energy intensity. Energy consumption characteristics in a country can predominantly influence all three components of SDG 7. Further, energy consumption is intrinsically linked to several energy policies. Understanding the nexuses will be conducive to the policymakers and energy community. This study aims at providing deeper perspectives on the influence of energy consumption by analyzing the changes incurred in renewable penetration, energy installed capacity, production and consumption-based emission, and emission intensity. The analysis is extended to four major energy consuming sectors (including industrial, transportation, residential and commercial sectors) in 40 countries. A thorough investigation is performed based on a clustering approach to identify the pattern among the energy consumption. This yielded three scenarios where countries have the highest energy consumption in the industrial (Scenario 1), transportation (Scenario 2), and residential sector (Scenario 3), respectively. Scenario 1 has higher energy consumption growth and renewable penetration can be achieved with a proper policy framework. Scenario 2 is observed to have stagnant energy consumption and promoting renewables needs additional efforts to decouple fossil fuel usage. Scenario 3 has moderate energy consumption growth and the renewable penetration is the highest. The residential sector is observed to possess the highest renewable energy consumption among the four energy-consuming sectors in all the scenarios. For the identified energy consumption patterns, a policy framework is proposed to substantiate energy sustainability in which policies are constructed in two stages, i.e., one to form the core policy and the other to sustain the core policy. The contributions of the study is further extended to delineate the relation between energy consumption and the three elements of SDG 7 (energy accessibility, renewable penetration, and energy intensity). Understanding the influence exerted by energy consumption patterns will be highly supportive in directing energy policies and the existing policies can be optimized with the findings of this study. [ABSTRACT FROM AUTHOR]

• We study the association between the Energy Trilemma Index (ETI) and education. • We use a statistical approach leveraging a dataset of 118 world countries. • School life expectancy is positively associated with the ETI. • The disposition to towards STEM degrees is not significantly associated with ETI. • Besides economic and environmental factors, also social factors can impact ETI. This study investigates the association between the Energy Trilemma Index (ETI) (which measures secure, affordable, and sustainable energy) and a country's level of education from a sustainable innovativeness perspective. We analyze if school life expectancy (SLE) and the students' predispositions towards STEM degrees (science, technology, engineering or mathematics) can stimulate the creation of sustainable and resilient energy systems. We perform a regression analysis based on data from 118 countries, and we employ both an ordinary least squares (OLS) regression and a robust-to-outliers MM-estimator. The statistical investigation reveals that the higher the school life expectancy, the higher the ETI. By contrast, we find no significant association between the ETI and the percentage of STEM graduates. So what matters in energy sustainability is the number of persons who decide to continue tertiary studies rather than their attitudes towards studying scientific subjects. This research paper contributes to the literature on renewable energy, circular economy (CE), sustainable innovation, and knowledge management by demonstrating how education can aid in implementing energy systems that adhere to the triple bottom-line approach (society, economy, and environment). Thus, sustainable and resilient energy systems can be spurred by not only environmental and economic variables but also social ones. Therefore, the traditional approach of the CE for achieving sustainable development should be substituted by alternative CE approaches that consider social variables. From the managerial standpoint, a high SLE can foster resilient energy systems through the creation of ad hoc policies, the birth of new companies connected to the renewable energy sector, and new organizational forms of energy management handled directly by citizens. [ABSTRACT FROM AUTHOR]

Abstract: The present paper introduces a life cycle modeling approach for representing actual demand of energy or energy intensive products delivered within a system (electricity, heat, etc.) for optimization of the energy mix, according to some of the available life cycle impact assessments (LCIAs). Unlike classical LCA modeling approach, the real amount of several energy products leaving the system and the interactions due to the presence of multi-output processes are considered within the present approach. As a case study, future scenarios are obtained for the Belgian electricity mix production and the heat mix potentially substituted by CHP or biomass, switching between abandoning or not power from nuclear energy. The possibility of using natural gas, biomass for cogeneration, wind power and solar photovoltaic energy are considered within the availability ranges of these resources. Finally, results are presented from successive optimizations according to the sustainability potential defined in a previous paper. A pathway to a more sustainable Belgian energy system is obtained. Finally it is concluded that under the modeling conditions and without nuclear energy it is not possible to obtain a reduction of GHGs and despite diminishing of non-renewable resource consumption, a rising of toxicity is obtained. [Copyright &y& Elsevier]

Abstract: Politicians and policymakers are searching for alternatives for current energy conversion systems in order to reduce environmental pollution whilst preserving scarce natural resources. When defining new alternatives it is important to find out how environmentally friendly and sustainable these alternatives are, and which of them will ensure a major improvement in environmental issue. To answer such questions the present work proposes a new type of indicator based on exergy life cycle data. Alternative energy routes towards different services and commodities are compared in terms of environmental impact and indirect natural resource costs. Two case studies are presented using data from the Ecoinvent database (v2.01 2007) to compare alternatives to petrol transport and fuel oil power generation. The alternative transport routes assessed were methanol and biogas fueled cars, and wind electricity in the case of power generation. [Copyright &y& Elsevier]

• Proposed a novel SDG 7 composite index for assessing energy sustainability. • Dimensions include clean energy, security, emission, intensity, accessibility. • Proposed ANMMO normalization method to reduce the influence of outliers. • SDG 7 composite index depicts a more accurate reality than the actual SDG 7 index. • Iceland, Norway, and Sweden tops in energy sustainability aspects. The Sustainable Development Goal 7 endeavors to ameliorate the energy system towards sustainability. Monitoring the country's progress to the goal will be of utmost for the government to take suitable actions and thus, constructing a performance monitoring index for Sustainable Development Goal 7 would tune the pace of implementation. This study aims to develop a novel Sustainable Development Goal 7 or Energy Sustainability Composite Index to assess the energy sustainability performance. Since Europe tends to have diverged efforts towards energy sustainability, assessing them with the proposed Sustainable Development Goal 7 composite index would provide the evidence needed for effective sustainable development strategies. By describing Europe, the authors signify 40 European countries and the selection of country depends on the availability of all the data that are required for the energy sustainability assessment. In this study, the analyzed energy sustainability aspects include clean energy conversion, energy security, energy accessibility, energy intensity and carbon intensity. The results show that Iceland, Norway, and Sweden tops in energy sustainability aspects with scores of 0.7313, 0.6967, and 0.6313 (on a scale of 0 to 1), respectively. The proposed Sustainable Development Goal 7 composite index is also compared with the actual Sustainable Development Goal 7 index, which comprises the indicators defined by the United Nations. The prime difference between the proposed Sustainable Development Goal 7 composite index and the actual Sustainable Development Goal 7 index resides in the consideration of energy security and carbon intensity indicators and in the framework designed to evaluate the clean energy prevalence. The evaluated actual Sustainable Development Goal 7 index scores of Germany and France are 0.4915 and 0.4656, respectively. On comparing with the proposed Sustainable Development Goal 7 composite index scores, the scores decreased by 20.9% for Germany and increased by 7.2% for France. The robustness of the proposed composite index relies on reducing the effect of outliers by using a modified min–max methodology, namely Aggregated Normalization based on Maximum and Minimum Outliers for normalization and the subsequent weightage allocation criteria utilized in Analytic Hierarchy Process methodology. Sensitivity analyses highlighted that the clean energy indicator is the most influencing indicator for the designed composite index. Nevertheless, uncertainty analysis indicates that the weightage scenario has a more prominent influence than various normalization and aggregation methods. [ABSTRACT FROM AUTHOR]

• SWOT-AHP analysis shows increasing solar and wind energy projects highly favors SDG-7. • Process tracing infers that unilateralism is preferred in reality amidst pandemic. • SDG 7 & SDG 13 possesses the highest SDG interaction and influence score, respectively. • Changes in the energy market, investment and political approaches have decisive roles. The United Nations (UN) have formulated seventeen Sustainable Development Goals (SDGs) and thus, humans were trying to traverse the sustainable path. Meanwhile, the COVID-19 pandemic has emerged and forced out the ephemeral conventional approaches. Thus, the post-COVID world indicates the need for sustainable development and strategies in par with the ecosystem. The authors propose this study as a guide to direct the post-pandemic scenario into the sustainable pathway by prioritizing energy sustainability to engage the actions for achieving the SDGs. The analysis in this study commences with the investigation of pronounced impacts in the energy sector with its influence on the progress towards sustainability. To pursue the path of energy sustainability, a qualitative analysis is performed in a parallel approach from the key viewpoint of the renewable and sustainable energy transition, digital transformation of the energy sector and energy affordability in the post-COVID world. A SWOT-AHP hybrid methodology is employed to identify the significance of each strategy or issues to be focused on immediately in the post-COVID world. The study also discusses energy sustainability from political bodies and policy makers' perspective, and the actual scenario where we are headed is revealed with the aid of process-tracing method. Furthermore, a novel quantitative analysis is established to represent the SDG's interaction and the result shows that the SDG 7 is the underpinning goal in relative to other SDGs. In context with it, the mapping of energy sustainability to the sustainable world is accomplished. The ultimate inference from envisioning the SDGs through energy sustainability shows that a sustainable world would result after the pandemic. However, the changes in the energy market, investment preferences and more importantly, the decisions influenced by the political bodies in the post-COVID-world is decisive in achieving the same in a stipulated time frame. [ABSTRACT FROM AUTHOR]