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[en] This article outlines that Germany must redouble its efforts to reach its objectives of reduction of greenhouse gas emissions defined for 2030, and that renewable energies are already representing more than the half of the German energy mix whereas its energy transition is controversial. Thus, the author evokes the huge investments made since 2000, the ambitious program of development of renewable energies, that this development is said to be too slow regarding some aspects. While evoking the example of a village which is considered as a model as far as successful energy transition is concerned, current developments are mentioned regarding infrastructures, notably the important issue of reinforcement of the high voltage network, and ecological and economic issues. The last part more particularly addresses the strategic importance of a local photovoltaic panel production, and actions and supports to phase out coal mining and use
[en] While France and a growing number of countries around the world have been setting ambitious goals for reaching net-zero emissions, variable renewables like wind and solar energy are set to become the main building blocks in power systems worldwide as countries seek to decarbonise their economies. In a new joint analysis commissioned by the French Ministry for the Ecological Transition, the IEA (International Energy Agency) and RTE (Reseau de Transport d'Electricite) describe four essential areas that policy makers must address when wind and solar PV start to dominate electricity generation. The new report, Conditions and requirements for the technical feasibility of a power system with a high share of renewables in France towards 2050, outlines four groups of strict conditions that need to be met to integrate very high shares of renewables in a technically secure way in a large and meshed power system such as that of France. - Power system strength: Even if they still need to be proven at large scale, there is a general scientific consensus that technological solutions to maintain system strength - and therefore stability - without conventional generation exist in several cases. Specific difficulties are expected in the case of a system with a significant share of distributed solar PV. Further assessment of the impacts of distributed PV on the power distribution network and their implications for electricity security is needed. - System adequacy: This is the ability of a power system to cope with a given load at all times. It can be ensured even in a system mainly based on variable renewables as long as substantial sources of flexibility are available, including demand-response, large-scale storage, peak generation units and well-developed transmission networks and interconnections. The maturity, availability and cost of different flexibility mixes need to be evaluated in further analysis. - Operational reserves: The sizing of these reserves and the regulatory framework for balancing responsibilities and procurement would need to be substantially revised in a large power system as such that of France. Moreover, forecasting methods for variable renewables would need to be continually improved. - Grid development: Substantial efforts would be necessary beyond 2030 at both transmission and distribution levels. This requires strong proactive steps and public engagement in long-term planning in order to assess costs and work with citizens on social acceptance of new infrastructure. These efforts can nonetheless be partly integrated into the renewal of ageing network assets. The joint study marks an important step and is part of a larger work program aimed at developing and comparing scenarios for the long-term transformation of the electricity system to achieve carbon neutrality by 2050. On 27 January 2021, RTE will open a public consultation assessing the framework and assumptions of these future scenarios, and will present the conclusions of this consultation in the Fall 2021.
[en] The government of India is promoting the electric vehicle industry to reduce the import dependence on crude oil and natural gas and to achieve ecological benefits. Electric vehicle projects are forging ahead due to the proactive policies of the government. The lithium-ion battery is an essential component of an electric vehicle. The lithium-ion battery is also used in the energy storage device and the communication sector. Presently, lithium-ion battery cells are not produced in India. Indian demand for lithium-ion cells are entirely met by import. However, battery packs are assembled in India with imported battery cells by a few units. (author)
[en] This publication comments the content of a report issued by RTE and the IEA on the conditions for a technical feasibility of scenarios exhibiting a high penetration of renewable energies (ENR) in France. It indicates the four conditions to be met for a security of supply and for the integration of very high proportion of renewable energies into a large scale electricity system: stability of the electricity system, supply security, operational reserves, grid development. These four conditions and the associated technical feasibilities stated in the RTE-IAE report are then discussed. The authors finally discuss whether a 100 pc renewable energy objective is actually to be wished.
[en] The cyanobacterium, Leptolyngbya sp. and green microalga, Chlorella sorokiniana as biofertilizers, play an important role in agriculture development. Due to a lack of information concerning microalgae as biofertilizers in crop production, the present research aimed to evaluate the possibility of increasing growth using microalgae as biofertilizers on seed germination of four commercially important vegetables i.e., radish (Raphanus sativus) subsp. sativus, spinach (Spinacia oleracea), turnip (Brassica rapa) subsp. rapa and fenugreek (Trigonella foenum-graecum). In the current study the fresh biomass of cyanobacterium, Leptolyngbya sp. and green microalga, C. sorokiniana was used as bio-fertilizers to note the effect on seed germination of four vegetables. The In vitro effects of bio-fetilizers were also noted on the different growth parameters i.e., germination percentage, days to germination (50%), plumule length, radical length, fresh weight and dry weight using Randomize Complete Designed (RCD) with factorial arrangement. The results compared with control showed an improved germination percentage using Leptolyngbya sp. (83.17%) and C. sorokiniana (80.47%). Both strains exhibited early germination (4.50 days) while C. sorokiniana showed the maximum plumule (33.88cm), radical length (4.46cm), fresh (1.38g) and dry weight (0.0708g) associated with Leptolyngbya sp. The treatment with B. rapa seed germination was 98.67% and took 1.78 days to germinate. The lowest germination (34.44%) was recorded in S. oleracea and took 6.56 days to germinate. After applying Leptolyngbya sp. on B. rapa and T. foenum-graecum seeds indicated the highest seed germination (99.67%). While B. rapa seeds germinated after one day while primed with C. sorokiniana. The maximum increase over check of germination percentage was observed in Leptolyngbya sp. (11.63%) and C. sorokiniana (8.60%). Both strains improved early germination (3.78%), plumule length (33.88%), radical length (60.31%), fresh weight (7.97%) and dry weight (5.79%). (author)
[en] The performance of Li-ion batteries (LIBs) is highly dependent on their interfacial chemistry, which is regulated by electrolytes. Conventional electrolyte typically contains polar solvents to dissociate Li salts. Herein we report a weakly solvating electrolyte (WSE) that consists of a pure non-polar solvent, which leads to a peculiar solvation structure where ion pairs and aggregates prevail under a low salt concentration of 1.0 M. Importantly, WSE forms unique anion-derived interphases on graphite electrodes that exhibit fast-charging and long-term cycling characteristics. First-principles calculations unravel a general principle that the competitive coordination between anions and solvents to Li ions is the origin of different interfacial chemistries. By bridging the gap between solution thermodynamics and interfacial chemistry in batteries, this work opens a brand-new way towards precise electrolyte engineering for energy storage devices with desired properties. (© 2020 Wiley‐VCH GmbH)
[en] The author comments and discusses the content of a study jointly performed by RTE and the IEA which addresses the conditions and prerequisites in terms of technical feasibility for an electric power system displaying a high proportion of renewable energies by 2050. These conditions are notably to preserve the stability of the power system despite the reduction of present steerable means, to develop new means of compensation of the huge variability of wind and photovoltaic sources, to completely resize security reserves in order to compensate production hazards, and to very strongly extend and strengthen transport and distribution networks in order to integrate additional flows of wind and photovoltaic electric power. Thus, after having discussed how to guarantee the system stability despite the reduction of steerable means, the author wanders whether a power system controlled by a necessarily complex artificial intelligence will be able to be absolutely cyber-secured. He outlines that validation on actual existing networks will probably be very difficult, and that the envisaged evolution globally bears risks of degradation of the security of supply of electric power. He finally states that any evolution of the power system can only be based on perfectly proven and resilient technologies.
[en] Nowadays, alloy nanoparticles (NPs) consisting of noble metals find much importance due to their enhanced localized surface plasmon resonance (SPR) in the visible range. Besides the compositional changes, the SPR of alloy NPs independently can be tailored by changing the shape and interparticle separation. Here, we report the effects of shape and interaction parameters ( b and K , respectively) on the plasmonic properties of Au–Cu alloy NPs considering Au concentrations in the range of 0.0–1.0 using a modified effective medium theory. There is always a single SPR for the alloys’ NPs. A large shift of this SPR peak from visible to infrared regions is seen with decrease or increase in the values of b or K . A linear variation of peak shift with 1/ b and an exponential decay variation of peak shift with 1/ K are observed. Although there is a small increase in the values of slopes (in the peak shift vs .1/ b curves) with increase in concentration of Au in the Au–Cu alloys, there is almost no change in the fitting parameter, s of the exponential decay function (in the curves for peak shift vs. 1/ K ) for different sizes of NPs and concentration of Au or Cu in the alloys. This establishes the universal nature of the exponential decay behaviour. These observations are consistent with the data for elemental (Au and Cu) NPs. The correlations between (i) shape parameter, b and the aspect ratio, AR and (ii) interaction parameter, K with the interparticle separation, s are established as in case of elemental NPs. The study thus, verifies the model further and establishes universality of the applicability of the model. (author)
[en] Here we have studied locally rotationally symmetric Bianchi-V Universe in the presence of modified theory for gravitation [f(R,T)theory] and for that, we considered a perfect fluid with heat conduction as the energy source. We used the law of variation for the deceleration parameter (DP) to solve field equations, as it gives a constant value of DP and is related to the average scale factor metric. Also, we have discussed the physical and geometrical properties of the model in detail. (author)
[en] Layered lithium-rich cathode materials have attracted extensive interest owing to their high theoretical specific capacity (320-350 mA h g. However, poor cycling stability and sluggish reaction kinetics inhibit their practical applications. After many years of quiescence, interest in layered lithium-rich cathode materials is expected to revive in answer to our increasing dependence on high-energy-density lithium-ion batteries. Herein, we review recent research progress and in-depth descriptions of the structure characterization and reaction mechanisms of layered lithium-rich manganese-based cathode materials. In particular, we comprehensively summarize the proposed reaction mechanisms of both the cationic redox reaction of transition-metal ions and the anionic redox reaction of oxygen species. Finally, we discuss opportunities and challenges facing the future development of lithium-rich cathode materials for next-generation lithium-ion batteries. (© 2020 Wiley‐VCH GmbH)