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This work assesses the role of biomass and municipal solid waste in isolated energy systems. For this, La Réunion, a French overseas territory in the Indian Ocean with a population of about 850,000, serves as a case study. Methodically, the study assesses technical biomass-based potentials based on an island-wide digital landscape model, detailed information on land use, soil, and climate, and a dynamic yield simulation tool, while technical waste-based energy potentials are calculated from local data. In total, 9 crops, 11 waste streams, and forested areas are considered. The potential contribution of biomass and waste to the energy system is studied in three scenarios. In all, unsustainable outcomes are avoided by valorizing only crop residues and applying sustainable harvesting rates to forests. Depending on the scenario, biomass or waste based energy could cover between 19% and 22% of 2019 electricity demand compared to an actual value of 6% (2019). Furthermore, prioritizing the production of secondary energy carriers allows to meet 8% of 2019 energy demand in the transport sector. These results are in good accordance with previous studies and scenarios on Réunion's energy transition. Given its bottom-up approach based on standard geoinformatic data, the proposed method is in principle transferable to other isolated regions, also in developing countries. A first, high-level assessment of four comparable island (states) shows that in three cases similar contributions of biomass and waste as in Réunion can be expected. As a next step, the purely technical assessment shall be complemented by economic considerations. • Method: Application of an innovative bottom-up and spatially resolved biomass potential analysis with local waste potentials. • Result: Exploitation of local energy resource potentials in biomass and waste can cover up to 49% of local electricity demand. • Transfer: The method can be applied to other isolated regions or developing countries. [ABSTRACT FROM AUTHOR]

Highlights • Near-wall vertical cable fire experiment was conducted in an analogue nuclear compartment. • Wall confinement and source-ceiling height variation effect was considered. • A new correlation for heat release rate of near-wall vertical cable fire was established. Abstract Nuclear power plant will be significant energy system for sustainable cities. The safety risk of the cable fire is an important issue for managing and operating a nuclear power plant. A simple and useful method to estimate the fire scale is urgently needed for safety management. In this work, experiment was conducted in a typical underground compartment of nuclear power plant, which primarily focused on safety monitoring and management of the vertically arranged cable. The burning characteristic of the cable was firstly measured by cone calorimeter. Then, full-scale experiment was conducted, in which the real-time heat release rate was recorded through mass variation and the real-time temperature beneath the ceiling was simultaneously measured by the thermocouples. A modified model to predict the real-time heat release rate of the vertical cable fire base on measured temperature beneath the ceiling was established and was then validated through the experimental result. It's shown that the predicted heat release rate could well match with that measured in the experiment. The results of this work may provide guidance for the cable fire risk assessment and safety monitoring, and may also provide reference for underground nuclear power plant design and safety management. [ABSTRACT FROM AUTHOR]

Abstract Article shows how system dynamics modelling (SDM) approach could be used in modelling the energy transition towards low carbon energy system. SDM can be used to combine the techno-economic and socio-technical analysis. The study considers flexibility issues related to integration of renewable energy sources. Simplified model structure is made to illustrate how flexibility as well as other socio-technical aspects might be modelled. Results of the model correspond to the behavior anticipated from the model structure. Namely, model imitates effects of technological disruption which rises the limits of intermittent power production from renewable sources which can be integrated into power system. The limits are increased stepwise, as a share of intermittent power production reaches certain threshold value, resulting in sequence of S-shaped growth. This study presents flexibility increase of a power system conceptually and more detailed study should uncover leverage points which could stimulate this increase and thus, transition to sustainable energy system. [ABSTRACT FROM AUTHOR]

Sustainable and clean multi-energy systems have been hybrid coordinated in microgrid (MG) to fulfill regional multi-energy users economically, but shortages and surpluses still exist. The growth of win-win energy sharing between MGs attracts attention to smart information center (SIC) concept in MGs' community, which facilitates sustainable solutions across three key objectives: lower carbon emission, sufficient utilization, and long-term cooperation. This paper designs a two-stage decision framework for day-ahead operations of SIC, where the first stage minimizes the total cost (i.e. operational cost and carbon emission cost) by the proposed multi-energy intra-scheduling and inter-sharing model (MIIM) and the second stage implements the smart cost-saving redistribution model (SCRM) to stimulate MGs in long-term joining of energy sharing. The extended alternating direction multipliers method algorithm (E-ADMM) is developed to protect the privacy of MGs' data while approximating the optimal solution of MIIM. The case study proves that a) demand response and energy sharing in MIIM result in cost savings of 2.01% for carbon emissions and 7.25% for total operations; b) renewable energy has been fully utilized and the total multi-energy loss has been avoided nearly 92.22% in MIIM; c) the asymmetric Nash bargaining approach fits the SCRM with incentive cooperation, whereby those who contribute more gain a higher share; d) the optimal gap of E-ADMM is less than 0.2% by iterated insensitive decision result from each MG, which computes in polynomial time when the scale of MG increases; e) the two-stage framework performs better with more heterogeneity of MGs. Furthermore, we provide valuable insights for guidance and models with worldwide generalization potential. [ABSTRACT FROM AUTHOR]

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The linked Nations estimate that 30%-40% of the world's energy use arises out of the operation of buildings, resulting in the release of many millions of tonnes of CO2 into the atmosphere either directly through the burning of fossil fuels or indirectly through the use of electricity produced at power stations. This current model of power generation and supply and ever growing demand is unsustainable and will need to adapt. The design and management of energy infrastructure for new and existing cities must change in order to make better use of resources through a combination of energy efficiency, application of new and emerging technologies and a shift to renewable sources of energy. The future of city energy infrastructure lies in an holistic approach to supply, demand and distribution. Security of supply and intermittency considerations need energy systems that can respond to changes in energy source availability and to changes in demand whilst ensuring resources are not wasted. Buildings and cities must he designed to work sympathetically with renewable energy supply systems requiring buildings that are not only designed to minimise energy use but be capable of responding to the condition of the supply network through short term dynamic control and storage. This paper will consider the interrelated nature of a city wide sustainable energy system in the context of the GCC states, identifying the key policy, design and operational principles required to achieve a successful outcome. [ABSTRACT FROM AUTHOR]

• Spin dependent DFT calculations are executed for MgPr 2 X 4 (X = S, Se). • Structural investigation represent FM stability of MgPr 2 X 4 (X = S, Se). • The band structures analysis show their FM nature of MgPr 2 X 4 (X = S, Se). • The computed optical parameters indicate potential opto-electronic devices applications. • Electronic thermal coefficients are probed and suggested studied spinels as promising sustainable energy materials. In this paper, density functional theory (DFT) calculations are performed to investigate the spin-dependent mechanical, electronic, magnetic, optical, and thermal transport properties of rare-earth-based chalcogenides MgPr 2 X 4 (X = S, Se) spinels. The mechanical properties are obtained by employing the modified Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol GGA). Also, the modified Becke and Johnson (mBJ) potential is engaged in examining the electronic, magnetic, optical, and transport properties. Structural stability in the ferromagnetic (FM) phase is confirmed by calculating the energy difference between the FM and non-magnetic states. Besides, the formation energies are computed for thermodynamic stability. The strong hybridization near the Fermi level comes from chalcogenides 2p-states and f-states of rare-earth metals, which results in the total magnetic moments. The in-depth optical properties are evaluated in terms of dielectric constant and refraction. Lastly, electronic thermal coefficients, such as Seebeck coefficient, electrical and thermal conductivity, and power factor, are also probed and suggested studied spinels as promising sustainable energy materials. [ABSTRACT FROM AUTHOR]