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[en] Rapid development of smart electronics, energy harvesting technologies are gaining tremendous attention to provide alternative energy for self-powered operations of wearable electronics, sensors, wireless networks and medical implants, followed by substantial interest from both academia and industry. In this framework, piezoelectric nanogenerator (PNG) is an energy harvesting device that converts ubiquitous mechanical energy (such as vibration, walking, body movement, keyboard typing etc.) available in our surroundings, into a faun of electrical signal based on the energy conversion by nanostructured piezoelectric materials. Thus issues associated with conventional battery systems such as limited life-span, large size, environmental pollution, compatibility and cost intensively are mitigated by harvesting solutions
[en] The climatic variation and deteriorating availability of fossil fuels needs to move the society towards renewable sources. The supercapacitor will become an attractive power solution to the increasing number of applications, such as renewable energy power generation, transportation, power system and many others, because of its advantages, which include high charge/discharge current capability, very high efficiency, wide temperature range, etc. Thus, supercapacitor is an emerging technology in the field of energy storage systems that can offer higher power density than batteries and higher energy density over traditional capacitors. In other words, one can say, it actually fills the gap between the batteries and conventional capacitors. Many metal oxides/ hydroxides have been studied extensively for the application of supercapacitor. The RuO2 is studied widely for sup supercapacitor, it also shows great performance as supercapacitor, but the costing and toxicity are the basic problems with this material and other oxide/ hydroxide material. Therefore, we have to move towards the alternative way, that is, cost as well as environment friendly material. The strontium hydroxide (Sr(OH)2) with tuberose dendritically branched structures has been grown successfully by successive ionic layer adsorption and reaction (SILAR) method at room temperature without using any surfactant or binder. The Sr(OH)2 film electrode exhibited the specific capacity of 413Cg-1 at 2 Ag-1 in 1 M NaOH electrolyte. The Sr(OH)2 can be emerged as a promising electrode material for supercapacitor application synthesized by low cost chemical method applicable to roll-to-roll technology, portable electronics, electric vehicles, large scale energy storage grid, etc. (author)
[en] Li-metal anodes are one of the most promising energy storage systems that can considerably exceed the current technology to meet the ever-increasing demand of power applications. The apparent cycling performances and dendrite challenges of Li-metal anodes are highly influenced by the interface layer on the Li-metal anode because the intrinsic high reactivity of metallic Li results in an inevitable solid-state interface layer between the Li-metal and electrolytes. In this review, we summarize the recent progress on the interfacial chemistry regarding the interactions between electrolytes and ion migration through dynamic interfaces. The critical factors that affect the interface formation for constructing a stable interface with a low resistance are reviewed. Moreover, we review emerging strategies for rationally designing multiple-structured solid-state electrolytes and their interfaces, including the interfacial properties within hybrid electrolytes and the solid electrolyte/electrode interface. Finally, we present scientific issues and perspectives associated with Li-metal anode interfaces toward a practical Li-metal battery.
[en] High energy storage devices have been extensively utilized for different applications in both Defence and civil sector. In the present scenario, the research efforts are mostly directed towards synthesizing novel nanomaterials to enhance the capacity and the stability of the fabricated device. Hydrothermal synthesis and Chemical vapour deposition (CVD) are two methods utilized to synthesize nanomaterials including mixed metal oxides which are extremely useful as far as high energy storage devices are concerned. In the present work, we report the optimization of synthesis of NiMoO4, and other mixed metal oxides using hydrothermal synthesis route. We also present different 1-D nanostructured morphologies fabricated using high temperature CVD processes with high surface area and 3-D hierarchical structures. Different parameters have been studied in conjunction with the electrochemical performance of the fabricated device to optimize the obtained energy storage capacity. Utilization of different substrates like nickel foam, carbon cloth and optimization of synthesis parameters over these substrates is also presented. We were able to achieve 3-D hierarchical nanostructures of NiO, NiCo2O4, NiMoO4, FeCo2O4, CoMoO4 using these synthesis routes on different substrates and in powder form. (author)
[en] Deregulation of electricity markets has brought about major changes in the ways investments in and operation of power plants are planned and optimized. Although many NPPs have seen reduced revenue in recent years as power purchase agreement end and wholesale market electricity prices have remained low, there are opportunities to expand the technical capabilities of NPPs, participate in additional market services and increase revenue. This transaction summarizes the opportunities provided by participation in ancillary services markets potentially made possible by integration of thermal energy storage capacity, specifically the Firebrick Resistance-heated Energy Storage System (FIRES), into future nuclear power plants with high-temperature reactors and Nuclear Air-Brayton combined cycle (NACC) power conversion. The restructuring, or deregulation, of electric power systems in most of Europe and North America has had a substantial impact on the economic performance of currently operating nuclear power plants (NPPs) and the prospects for new builds. Owners of NPPs in some markets have expressed concern that low wholesale electricity market prices and insufficient compensation for capacity, reliability, and other services are threatening the financial viability of their plants. However, both current and future NPPs have the potential to increase their competitiveness by increasing the flexibility of their electricity output. Flexible output has previously only been possible in water-cooled reactors through load-following operation, which requires core power maneuvers and operation of the steam turbine at reduced efficiency. Integration of thermal energy storage systems (TESS) provides an alternative, providing the plant the option to either output electricity or store heat for greater later electric output. The plant owner may thus increase sales of electricity during hours when it is most valuable. Even more, some TESS technologies have the potential to greatly increase the net ramp rate capability of the plant. The ability to rapidly change net power output to the grid may make it possible for NPPs to secure additional revenue by providing additional minute-by-minute balancing services to the grid. FIRES is only one technology out of many that might provide additional technical capabilities at NPPs, and this discussion has only highlighted the opportunities in a single market. Analysis of other options, include steam accumulator systems, nitrate salt TESS, phase change material TESS, and opportunities in other markets are subjects of ongoing work. Deregulation of electricity markets has brought about major changes in the ways investments in and operation of power plants are planned and optimized. Although many NPPs have seen reduced revenue in recent years as power purchase agreements end and wholesale market electricity prices have remained low, there are opportunities to expand the technical capabilities of NPPs, participate in additional market services, and increase revenue. (authors)
[en] Conclusion: Ghana’s electricity generation mix developed along line its ambition to attain a high income status in fulfillment of the socio-economic aspirations of its people. The assessment considers the influence of the future electricity generation on greenhouse gas emission. The results indicate that nuclear power can play a key role in greenhouse gas emission mitigation, due to the dominant role it is expected play in the electricity generation mix. The low contribution of renewable sources is due to limitation in their resource availability in Ghana particularly in the case of hydro, wind and biomass. Even though solar is abundant by virtue of Ghana’s geographical location, the unavailability of cost effective energy storage system in the foreseeable future imposed limitations on its wide spread use. The Introduction of nuclear power in Ghana is confronted by a major challenge which is financing. The high capital cost of NPPs makes it currently difficult for government to finance them calling for arrange with vendor countries through build operate and transfer arrangement, public private partnership (PPP), etc. In addition, some decision makers and some members of the general public have concerns about nuclear safety, particularly in the case where Ghana is a developing country. This therefore calls for public education to allay their fears and negative perception about the technology.
[en] In this research, the pomelo peel (PP), carbonized pomelo peel (CPP), and activated carbonized pomelo peel (ACPP) were used to adsorb capric-myristic-stearic fatty eutectic (CA-MA-SA) to prepare the novel shape-stable composite phase change materials (SS-CPCMs) of CA-MA-SA/PP, CA-MA-SA/CPP, and CA-MA-SA/ACPP using the heating-ultrasonic method. The properties of these SS-CPCMs were contrastive analysis. The scanning electron microscopy (SEM), x-ray diffraction (XRD), and specific surface analysis (BET method) illustrated that specific surface area of ACPP is much higher than others, which is fit for adsorption. SEM showed the CA-MA-SA was absorbed into the pore of ACPP. The differential scanning calorimeter analysis (DSC) revealed that these SS-CPCMs have a close phase change temperature of 19 °C, but the heating enthalpy of CA-MA-SA/ACPP is 128.5 J g−1, which is much higher than another two. The thermogravimeter (TG) and Fourier transform infrared spectroscopy (FT-IR) indicated that the CA-MA-SA/ACPP performed well in not only thermal stability but also chemical compatibility. In addition, the CA-MA-SA/ACPP has a superior thermal reliability after 250 thermal cycles. So the ACPP is a good supporting material, and the CA-MA-SA/ACPP is a promising SS-CPCM due to the above great properties, which is suitable for the thermal energy storage system. (paper)
[en] A potential deployment strategy for Small Modular Reactors (SMR's) is in hybrid energy systems where the presence of intermittent energy sources (wind and/or solar) subjects the reactor to a time varying electric load (1). Proposed options for accommodating this load have included operating the reactor in a load follow mode, or operating the reactor at or near steady state and bypassing steam around the turbine directly to the condenser (2). Both of these strategies result in lost energy potential. With the large financial investment associated with a nuclear power plant there is strong economic incentive to run the plant at maximum capacity. One method to accomplish this is the installation of Thermal Energy Storage (TES) that can be charged when grid demand is less than 100% plant capacity. The thermal energy can then be recovered, either as a supplement to the power plant during peak demand times, or can be used for other processes (1). Sensible heat thermal energy storage systems have been proposed for solar energy systems (3). This paper describes such a system for SMRs. These results show the feasibility of a TES system alongside a nuclear power plant that can limit load following operations for the reactor. Load following results in a decrease of capacity factor for the plant along with imposing significant stresses to plant equipment. With the implementation of a TES system these stresses can be transferred from the nuclear plant to the TES system. Not only does this equate to a longer overall life of the plant's hardware, but it also will dramatically increase the capacity factor of the system. This increase in capacity factor will lead to an improved economic return over the lifespan of the reactor. Future development in the near term will focus on coupling the TES system to the dynamic response of the reactor and energy conversion system and developing the models necessary to implement the discharge mode. (authors)
[en] The present work is intended to investigate the charge carrying properties of nanomaterials for super capacitor applications by electrochemical studies. The nanomaterials were fabricated by green route process by the rhizome of Corallo carpus epigaeus for the first time. The silver nanomaterials were composited over the zinc oxide nanomaterial to improve the efficiency of the energy storage system. The Fourier Transform Infrared spectrum confirm the functional molecules present in the nanomaterial. The Field Emission Scanning Electron Microscopic images evidenced the oval shape of zinc oxide and hexagonal shape of silver nanomaterials. The purity of the nanomaterials was investigated using energy dispersive spectrum. The structural property of the material was studied by x-ray Diffraction. The energy storage capacity was investigated by electrochemical studies. Higher efficiency was observed when the impurity is added with the base material. The specific capacitance was calculated as 160.8 F g−1 for ZnO nanomaterials and 189.52 F g−1 for ZnO/Ag nanocomposites at the current density of 0.5 A g−1. The electrochemical impedance studies were also carried out for the fabricated nanomaterials. The ZnO nanomaterials possess 603 Ω of electron transfer resistance. While adding Ag+ ions over the ZnO nanomaterials, the conductivity (Ret = 489 Ω) was remarkably increased. (paper)
[en] A comprehensive survey of electricity utilities around the world, was conducted as a part of the GEI activities in 2014, covered countries that together account for over 80% of global installed generation capacity (see Figure 1). The survey confirms that: - The goal of providing access to energy for all people in the world by 2030 set by the UNSE4ALL shows insufficient progress, particular in Asia and Africa. This goal will not be achieved, unless governments, industry and the international community undertake immediate concerted action. - Renewables and other carbon-free technologies will continue their strong growth and their share in the fuel mix will increase, as they are expected to help reduce carbon emissions and complement utilities' supply of electricity from conventional energy sources. Nevertheless, the fuel mix of the GEI utilities between 2015 and 2035 will still be dominated by fossil fuels, primarily coal and natural gas. - For the large-scale deployment of renewables and other carbon-free solutions, the introduction of advanced new technologies such as energy storage, smart grids or carbon capture and storage (CCS), needs to be accelerated and some regulatory barriers should be removed. - The CO2 price will need to increase considerably to bring about a significant shift in investment decisions. Long-term thinking, commitment and a meaningful carbon price are important factors to be taken into account when deciding to redirect investment. - To manage climate change effectively, investment in adaptation is as important as in mitigation, hence investment in adaptation research and development will need to increase. - Frequently changing and sometimes contradictory regulations and expectations from different stakeholders, including governments, industry and consumers are inhibiting efficient management of utilities. Clear, long-term, consistent and transparent ground rules are required. - Providing reliable supply of electricity to customers is the main business for utilities. To remain efficient and competitive, utilities are closely monitoring developments in their operating environment and adjusting their business models to reflect new emerging challenges. Currently, many utilities are focusing on regional integration to enhance energy security and increase integration of renewables. - The growing land and water requirements are becoming major issues, not only in the markets where utilities operate, but also globally. This will affect the development of new power generation projects and other infrastructure. The report also showcases best practice examples from around the world.
[fr]La Global Electricity Initiative (GEl) est un partenariat etabli en 2012 entre trois des plus grands reseaux de l'energie et du developpement durable: le Conseil Mondial de l'Energie (CME), le World Business Council for Sustainable Development (WBCSD) et le Global Sustainable Electricity Partnership (GSEP). Cette initiative a pour principal objectif d'encourager l'action et la cooperation entre les utilities du monde entier pour atteindre l'acces a l'electricite pour tous en 2030, de maniere fiable, abordable et durable. GEl a pour ambition de creer une communaute internationale des dirigeants de l'industrie electrique. Par ailleurs, GEI realise regulierement des enquetes qui identifient, decrivent et partagent les informations, les principales evolutions et enjeux et les meilleures pratiques: ceci favorise l'action des utilities pour ameliorer l'acces a une electricite abordable et propre. Enfin, GEl communique les messages des dirigeants de l'industrie electrique aux decideurs politiques et apporte sa contribution a d'autres activites du CME. Resultats de l'enquete: La derniere enquete mondiale aupres des utilities, realisee en 2014, couvre des pays representant plus de 80 % de la puissance installee. Ses conclusions sont les suivantes: - Sur la base des tendances actuelles, dans un scenario Business As Usual, l'acces universel a l'electricite ne sera pas atteint en 2030. Cependant, il est encore possible d'atteindre l'objectif d'ici 2030 si, et seulement si, les gouvernements, les industriels et la communaute internationale engagent immediatement une action concertee et adoptent une approche differente et un nouveau modele d'affaires. - Le monde continuera de dependre des combustibles fossiles pour la production d'electricite pendant de nombreuses annees. Neanmoins, les utilities developpent de nouvelles technologies renouvelables sans carbone. Pour le deploiement a grande echelle de ces solutions, II convient d'accelerer l'introduction d'avancees technologiques telles que le stockage de energie, les reseaux intelligents ou le captage et stockage du carbone: il faudrait parfois lever des obstacles reglementaires. - Les utilities sont souvent soumises aux attentes contradictoires des gouvernements, de l'industrie, des consommateurs et des autres parties prenantes. Comme le secteur de l'electricite est encore regule, les regulateurs doivent adresser des messages et des orientations clairs et coherents. - La securite de l'approvisionnement constitue la premiere priorite des utilities. - Le changement climatique est une realite et l'accent devrait etre desormais mis sur les mesures d'adaptation comme d'attenuation. - Une vision, un engagement de long terme et un prix realiste du carbone sont necessaires pour reorienter les investissements. - Le lien energie-eau et la concurrence pour l'usage des sols deviennent des enjeux majeurs.