Results 1 - 10 of 1519
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[en] With an ever increasing electrical load demand and the associated fuel price to generate it, researchers are compelled to find alternate, cheap and environment friendly ways for power generation to cater to this technoeconomic conundrum. Renewable Energy Sources (RES) are now being integrated in Distributed Generation (DG) based environment as a solution to this problem, hence resulting in Microgrids, with multiple sources and loads demarcating their footprint. Control and management of a diverse generation profile within a single microgrid is arduous and computationally intensive for a single centralized controller. .This paper addresses this inherent problem and proposes a decentralized Multiagent based intelligent control technique to efficiently encompass the heterogeneous generation profile of Microgrids. Artificial Neural Network (ANN) based intelligent agents are deployed at the planning stage for each component of the Microgrid. These agents are responsible for maintaining individual local control parameters within the prescribed control margins, hence creating a multi-agent environment in a Microgrid structure. The proposed intelligent multi-agent control scheme is tested on a test system to furnish its merits over its traditionally employed counterparts. Simulation results show that ANN integration not only reduced the computational burden but also reduced the overall operating cost (around 10.2 %) by reducing the thermal generation. (author)
[en] Twice a year, RTE publishes a forecast study of the electricity supply and demand in continental France for the summer and winter periods. The study is based on the information supplied by electric utilities concerning the expected availability of power generation means and on statistical meteorological models. Safety margins are calculated using thousands of probabilistic scenarios combining various production and consumption situations. This report is the November forecast study for the winter of 2021-2022 and its update at the transition between the two years
[en] In organizations that manage physical assets, the figure of the maintenance department carries out its work by managing an annual budget dedicated to maintenance and hoping that with greater or lesser luck there will not be a serious breakdown and that the availability of the asset is the maximum. The article presents a methodology where we can correctly identify the state of the asset with combined maintenance optimization tools (amfe, criticality analysis, life cycle analysis and RCM) that can optimize the maintenance budget and justify investments. 'Remaintenance' is defined as the combination between the optimization of maintenance and the redesign of the asset 'reinventing' the function to be fulfilled by the systems identified as critical in said analysis, and thus being able to justify before the organization projects to improve the asset as an increase in business income. (author)
[en] In Latin America, dams are the main source of electric power in most countries, with hydroelectricity providing 45 per cent of needs. They should play an important role in the policy of decarbonization but climate change is actually threatening their production because of higher temperatures, rainfall fluctuations, extreme events, and glacier melt. A study performed by the IEA showed that their electric power production could decline by 8 per cent by 2060. The study also stated some recommendations to improve resilience: dam modernization, insurance against climate risks, scientific policy, technical modifications of dams and equipment, construction of small dams upstream of the existing ones, construction of installations to control sediments, of dykes to protect dams, and so on
[en] Decarbonization of the electric power industry is an important step toward meeting emission goals to help prevent climate change. Nuclear power plays a significant role in decarbonization as it’s the largest zero emission energy source. There are other benefits to nuclear power being part of the energy portfolio with other renewable sources; however, the nuclear power industry faces economic challenges which have contributed to premature closure of plants. A U.S. federal policy for zero-emission credits (ZEC) could allow for existing nuclear plants to continue operating as well as promote the deployment of advanced reactors. Similar policies have been established state-level with proven results. A US federal policy with a dedicated timeline would allow utilities to make better informed decisions regarding the continued operation of plants as and the development of new reactors. While this paper focuses on the US, ZECs could be applied globally with similar benefits.
[en] The development and implementation of an appropriate infrastructure to support the successful introduction of nuclear power and its safe, secure, peaceful and sustainable application is an issue of central concern, especially for countries that are considering and planning their first nuclear power plant. In preparing the necessary nuclear infrastructure, there are several activities that need to be completed. These activities can be split into three progressive phases of development. This publication provides a description of the conditions expected to be achieved by the end of each phase to assist with the best use of resources. ‘Milestones’ refer to the conditions necessary to demonstrate that the phase has been successfully completed
[en] The legally guaranteed feed-in tariff for electricity generation from renewable sources has created a strong investment dynamic in wind and solar parks in Germany. Power generation is shifting from large centralised power plant units to decentralised, comparatively small and remote units with largely intermittent output and limited predictability. Large units suffering from low utilisation and consequent investment backlogs are hardly used any more. In addition, the gradual nuclear phase-out is almost complete and highly efficient fossil-fuelled power plants that are expected to run for the next two decades have to be decommissioned due to lack of profitability. Questions of supply security and grid stability are controversially discussed not only by experts but also in the public perception.
[de]Die gesetzlich garantierte Einspeisevergütung fiir die Stromerzeugung aus erneuerbaren Quellen hat in Deutschland für eine starke lnvestitionsdynamik in Wind- und Solarparks gesorgt. Die Stromerzeugung verschiebt sich von großen zentralen Kraftwerksblöcken zu dezentralen, vergleichsweise kleinen und abgelegenen Einheiten mit weitgehend intermittierender Leistung und begrenzter Vorhersehbarkeit. Große Einheiten, die unter geringer Auslastung und infolgedessen Investitionsstau leiden, kommen kaum noch zum Einsatz. Zudem ist der schrittweise Atomausstieg nahezu vollständig abgeschlossen und hocheffiziente, fossil befeuerte Kraftwerke, die für die nächsten zwei Jahrzehnte laufen sollen, müssen wegen mangelnder Rentabilität stillgelegt werden. Fragen der Versorgungssicherheit und Netzstabilität werden nicht nur von Experten, sondern auch in der öffentlichen Wahrnehmung kontrovers diskutiert.
[en] This publication introduces the general principles underlying the provision of technical and scientific support to a regulatory body and the characteristics of organizations providing such support. It describes the services provided to support regulatory functions as well as the associated activities and processes to maintain the needed level of expertise, state of the art tools and equipment. The publication is intended for use primarily by organizations that provide technical and scientific support in the field of nuclear and radiation safety. This also includes organizations that acquire such support, and regulatory bodies and governments, as they make decisions on the model of technical and scientific support to be developed at the national level, for example in the case of a country embarking on the development of a nuclear power programme. It is the first IAEA publication dedicated to the specific practices and challenges to be met by the technical and scientific support organizations.
[en] Several organizational changes took place as a result of the TMI-2 accident, changes which affected the licensee as well as the NRC as the regulator. The initial organizational structure that was formed to manage the aftermath of the accident included a staff of nearly 2000 people located on-site, staff that were focused on the immediate effects of the accident, including leaders from across the U.S. nuclear industry. The second organizational structure, in place by 1980, was described as being more “departmental in structure” with additional focus being placed on radiological controls and issues given that the level of personnel protection required at the TMI-2 site was markedly more than that normally required at an operating power plant. The third organizational structure focused more on the “growing sophistication of project management in terms of understanding the requirements for recovery, the overwhelming organizational need to make the project work efficiently, and the fact that, with the plant in effective cold shutdown, the need for redundant organizations was eliminated”. The fourth organizational structure, established around 1985, was mostly focused on defueling operations. Organizational changes were made to the U.S. nuclear industry as a whole based upon recommendations of the Kemeny Commission, and as a result, the Institute of Nuclear Power Operations (INPO) was established in December 1979 with the mission “to promote the highest levels of safety and reliability – to promote excellence – in the operation of commercial nuclear power plants”.
[en] The plant efficiency of a nuclear fusion power plant is considered. During nominal operation, the plant efficiency is determined by the thermodynamic efficiency and the recirculated power fraction. However, on average the reactor operates below the nominal power, even when the long shutdown periods for large maintenance are left outside the averaging. Hence, next to the recirculated power fraction the capacity factor must be factored in. An expression for the plant efficiency which incorporates both factors is given. It is shown that the combination of high recirculated power fraction and a low capacity factor, results in poor plant efficiency. This is due to the fact that in a fusion reactor the recirculated power remains high if it runs at reduced output power. It is argued that, at least for a first generation of power plants, this combination is likely to occur. Worked out example calculations are given for the models of the power plant conceptual study. Finally, the impact on the competitiveness of fusion on the energy market is discussed. This analysis stresses the importance of the development of plant designs with low recirculated power fraction. (paper)