Energy nexus最新文献

India is a developing country that is facing a major energy challenge. At the heart of this challenge lies the provision of electricity, which is vital for India's sustainable economic development yet faces major uncertainty in the future. A growing body of literature on planning studies has evaluated the future pathways open to India's power generation sector. In particular, several system planning studies have been undertaken at the state level to capture specific local features in energy supply–demand dynamics and to inform policies and initiatives for sustainable growth at the national level. This paper reviews the wider electricity planning literature, considering those states that have so far been studied the most from a modelling perspective (i.e. Andhra Pradesh, Assam, Gujarat, Karnataka, Kerala, Maharashtra, Tamil Nadu, Rajasthan and West Bengal), and scrutinises the various analyses performed by considering their modelling approach and analytical methods, programming techniques, evaluation criteria/objectives (e.g. economic, technical, environmental), planning horizon and time step, energy mix configurations (including the technologies implemented, fuels and storage systems), and key relevant technical and economic modelling features. Progress trends and challenges are presented and crucial gaps in the modelling field are highlighted to contribute to the international debate on the prospects of and challenges for India's future energy system.

As the need for renewable energy continues to grow, there is an increasing requirement to utilize systems that offer enhanced performance and efficiency. Consequently, a comprehensive investigation is conducted on a two-stage thermoelectric heat pump. The primary objective is to assess the impact of various influential factors on the overall effectiveness of the system. This exhaustive parametric study aims to provide valuable insights into the system's performance and efficiency. Subsequently, the multi-objective optimization approach considers both technical and economic goal functions. By incorporating these two aspects, the optimization process seeks to achieve the most favorable balance between technical performance and economic feasibility. This allows for a holistic assessment that takes into consideration not only the system's efficiency and effectiveness but also its economic viability in real-world applications. The best optimal solution is discovered using a variety of methods for multi-objective optimization. The optimized system is examined from both an exergy and an exergoeconomic vantage point after the best optimal solution has been identified by comparing the results of various methodologies. The outcomes demonstrate that for the multidimensional analysis of Linmap, the combination of multi-objective particle swarm optimization (MOPSO) and the linear programming technique yields the best optimal solution. The objective functions for this final optimal solution are unit cost of heating power and exergy efficiency, which are defined as 1.91 and 51.28 USD/(kWh), respectively. The results showed that the optimal current for temperature changes of 10, 20, and 30 K is 2.84, 5.53, and 8.1 respectively. Also, the optimal length and number of thermocouples were 0.0055 m, 30, and 15 m respectively in all techniques. The optimal current changes from 23.30 to 27.60 A, which indicates that the optimization technique prefers to adjust the current over other effective parameters. When the thermocouples in the first and second stages are 30 and 15 pairs, respectively, according to the design parameters of the ideal point, the system will work at its peak efficiency.

Smart integration of water, energy, agriculture, and environmental systems can create synergies, increase socio-economic benefits, and minimize environmental impact. However, effective planning of integrated water-energy-food-environment systems (iWEFEs) requires high resolution temporal and spatial data on various environmental and socioeconomic variables. Insufficient data availability and accessibility hampers the implementation of iWEFEs, particularly in remote areas of low- and middle-income countries. Addressing this gap, first, essential variables for the planning of iWEFEs are identified. Next, remote datasets are evaluated and selected regarding their suitability to serve for the planning of iWEFEs using a multi-criteria-analysis considering data accessibility, spatial coverage, spatial resolution, temporal resolution, and temporal coverage. Remote and in-situ data collection for the identified WEFE variables are implemented using a pilot case study of a smallholder farm in the data-scarce tropics of Costa Rica. The remote data collection is automated via APIs to open servers, data analysis and data visualization scripts, and complemented by an online survey. In-situ measurements are recommended to address data gaps in remote sensing, which are especially prevalent in the water domain. The research shall lay the foundation for free, open and automated data collection enabling the planning of iWEFEs worldwide.

PhotoVoltaic (PV) systems are often subjected to operational faults which negatively affect their performance. Corresponding to different types and natures, such faults prevent the PV systems from achieving their nominal power output and attaining the required level of energy production. Regarding the operational optimization of PV systems, this paper aims primarily at surveying and categorizing different types of PV faults, classified as electrical, internal, and external, where each is thoroughly investigated: internal faults occur at the PV cellular level, and can either be short circuit, open circuit, bridging, or bypass diode faults. External faults on the other side are mainly classified as temporary (i.e., clouds shading, snowstorms, etc.) or permanent (e.g., glass breakage, frame defects, etc.) mismatch faults. Lastly, electrical faults involve common circuitry problems, such as short circuits (e.g., line to ground, line to line, etc.), power processing units’ faults (e.g., inverter faults), and arc faults. As for the detection methods, six major fault detection methods are investigated for the AC side of the PV system with twenty-nine total AC based fault detection methods. On the other hand, eleven major fault detection methods are surveyed for the DC side of PV systems with seventy-three total DC based fault detection methods. The investigated methods are critically analyzed, and compared relevantly to each other, within the mutual sub-sets. The resulting tabulated comparative data assessments for PV faults (i.e., cause-effect relationships, impact on the PV system performance), as well as for faults detection methods (i.e., priority for application, etc.) compose a rich background for related PV systems’ performance security fields, where a nexus future work is also suggested.

Background

In Sub-Saharan Africa, the place of cooking and choice of fuel for cooking have detrimental effects on health due to excessive exposure to smoke. This study explores household-level exposure to the risk of cooking smoke and its associated determinants.

Methods

Using a quantitative approach, we pooled the most recent waves of the Demographic Health Survey dataset yielding 442,339 households from 33 countries in Sub-Saharan Africa. In this study, we first construct disaggregated measures of smoke exposure risk, determine the extent of households’ vulnerability to this risk, and investigate the associated determinants. We used the ordered probit regression to examine the socio-demographic and economic determinants of the levels of household smoke exposure risk in SSA.

Results

We found evidence that 67 % of households cook indoors while 86 % use smoke-producing fuels for cooking which, may indicate a high level of vulnerability to smoke exposure. As expected, 53 % of households have a high risk of smoke exposure. Our findings reveal factors such as wealth, size, educational level, and age of household heads as the key determinants of the disaggregated smoke exposure risk measures. For robustness, we grouped households by their rural-urban locations to establish evidence of the determinants.

Conclusions

The study identifies socio-economic characteristics as essential variables in determining a household's level of exposure to cooking smoke risk in SSA. We, therefore, propose to policymakers in the sub-region to improve the accessibility to clean cooking fuels, especially to all rural households. In this light, we recommend the promotion, subsidization, and enforcement of policies to encourage households to use clean cooking fuels.

The nexus of solid waste management problems and energy crisis necessitates the utilization of lignocellulosic biomass agro residues and municipal solid wastes for fuel and energy generation. Thermochemical technologies like pyrolysis, hydrothermal liquefaction and gasification are promising options to produce bio-oil, bio-crude and syngas from biomass, which can be further catalytically upgraded to hydrocarbon fuels. While there are technical merits associated with these processes and the products derived from them, the sustainability analysis of the processes from a systems level is imperative to evaluate their commercial viability. This perspective article presents fundamental understanding, importance and analysis of the different sustainability metrics based on mass and energy. The salient properties of biomass and wastes, and that of various fuels derived from them are presented. The three technologies are evaluated based on key metrics such as energy recovery/efficiency, E-factor, process mass intensity and CO₂ footprint. The E-factor for different technologies follows the trend: hydrothermal liquefaction (0.14) ≈ gasification (0.13) < pyrolysis (0.5). However, it is clear from the analysis that the E-factor and GHG emissions of the HTL process, a promising feedstock-agnostic pathway, can be further reduced by valorizing the organic-laden aqueous phase and upgrading the bio-crude to hydrocarbons. The key results of process technoeconomics are presented and assessed from a sustainability viewpoint. This study recommends the use of simple sustainability metrics in research works on thermochemical conversion so that the results from different studies can be compared on a common sustainability platform.

The vast majority of countries arguably agree that the planet is reaching a point of no return regarding global warming and climate change. Proof of that is the 2030 Agenda and the Paris Agreement, ratified by almost every nation worldwide. However, despite signing both great commitments, the states have made too little to meet the sustainability plans. Among the targets, renewable energy sources stand out to mitigate greenhouse gas emissions, but still, petrol wells continue to be drilled, and vehicle assemblers keep investing in new technologies for running their cars with fossil fuels. At the same time, government policies seem to be betting all their chips on electric engines, as if electricity were the best substitute for oil. This critical review analyses the pros and cons of such alternative fuel for road passenger transport, also taking into account another potential substitute for gasoline: bioethanol. In the following pages, we address the challenges and avenues of both alternatives and demonstrate that diversification of the global energy matrix and the biomass feedstocks should be our guiding principles.

The current environment and economic crisis demand the development of energy sources which can solve the problems of depleting energy sources while improving the economy and the environment. Transport sector constitute one of the highest consumptions of fossil fuels while generating harmful greenhouse gases causing global warming. Biofuels have been developed as the alternative clean fuel which can act as a substitute to replace or reduce the heavy usage of exhaustible fossil fuels. Production of biodiesel from microalgae has been considered one of the most feasible approaches towards circular economy. This review gives an in-depth information on the application of microalgae for biodiesel production, factors affecting their growth and techniques to produced biodiesel and other industrially important products benefitting the economy, environment and the society. It provides an intensive information on the biomolecules that can be valorized for commercial purpose and the metabolism of those biomolecules and also highlights the current status of production, challenges and the future prospects of microalgae in biodiesel and other production industries.

Energy is a crucial input in determining the agricultural growth of an economy. Thus, this study aims to investigate the impact of energy consumption (EC) on agricultural productivity growth (APG), specifically in relation to rice and millet yields in Odisha, India. The study uses data from the period spanning 1990–91 to 2019–20. The study uses an autoregressive distributed lag (ARDL) bound F-test to examine for a cointegration relationship amid the variables, and an ARDL regression framework to investigate the effect of EC on the yields of rice and millets in Odisha. The results advocate that there exists a long-run equilibrium relationship amid the variables in the study. Regarding the result for long- and short-run elasticities, it is evidenced that EC has a positive and statistically significant effect on rice yield and has no statistically significant impact on millet yield in the long-run. However, in the short-run, EC has a positive and statistically significant effect on both rice and millet yields. According to the findings of the current study, the state government of Odisha should place a greater emphasis on ensuring that farmers have access to power in order to encourage agricultural expansion and improve crop yields.

This paper scrutinizes the interrelationships among renewable energies, foreign direct investments (FDI), information and communication technologies (ICT), trade openness, and total factor productivity (TFP) in the context of Tunisia from 1984 to 2019. For that reason, we empirically use the autoregressive distributed lag model (ARDL) with breakpoint. The results of this study reveal the prominent contribution of FDI and TFP in the sustainable energy transition. Therefore, the diffusion of renewable energies should no longer be done only by the government but the private sector should take part in this transition by encouraging FDI. However, our results reveal that trade and ICT inhibit the process of transition to renewable energies in Tunisia. This fact may be explained by the economic recession, bad governance, and political instability which have delayed the implementation of new technologies in vital sectors of the economy, specifically the energy sector. On the other hand, applying a test of causality in the frequency domain has confirmed the presence of one-way causal relations from clean energy to ICT in the long term and from clean energy to FDI in the short and medium term. In addition, there is a bi-directional causal association between TFP and sustainable energy in the long term. Finally, the occurrence of causality from trade to sustainable energies was confirmed.