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[en] Full text: The DEMO reactor is expected to be the first application of fusion for electricity generation in the near future. In DEMO, magnet system management is of central importance as the driver of many crucial aspects such as nominal performance (toroidal field scales the fusion power), overall investment budget (∼1/3 of the total construction cost), production efficiency (full-power total availability heavily impacted by magnet downtime). Therefore, a careful approach is requested for this kind of component to ensure a safe design compatible with a power plant production conditions, keeping control on the factors prone to degrade the economic model (cost, risk). The derivation of those considerations into practical activities results in a constant attempt to lead in parallel extensive design activities and the mastering of upstream knowledge in magnet behaviour. This enables to consolidate to the most extend crucial design choices (e.g., the operation temperature margin) by valorizing a maximum of breakthrough either in technological progresses or in knowledge of physics-related phenomena (e.g., instabilities in transient regimes). To this end, DEMO magnet system design activities were continuously conducted in Europe, particularly evolving since 2011 in structured environments, always in collaboration with several laboratories. Since then, the actors underwent preparatory design phase and then the preconceptual design activity (CDA) phase, that led to design evolution in many aspects, from associated tools and methods to strategic considerations. Through 2011–2016, the DEMO magnet design was set for TF and CS systems but reinforced by ad-hoc tools (integrated and macroscopic mechanical design tools) developed to allow efficient predesign of TF and CS coils. R&D also provided assessed values of effective strain that strongly consolidates future design to come. Finally cross-fertilization between codes (at system and magnet scales) ensured alignment across the top-bottom flow of magnet functional features (e.g., TF allocated radial build). The results will be presented here. (author)
[en] The purpose of this paper is to indicate the vast gap in the utilisation of nuclear power between advanced and developing countries, identify some of the major problems encountered in the introduction of nuclear power into developing countries and suggest some possible approaches to overcome them.
[en] Highlights: • We provide scale efficiency measurements for multi-output cost minimizing producers. • Our method is nonparametric and takes the economic objective of the producers into account. • Our method can be used without observing the input prices. • We perform an analysis of more than 3300 US electricity plants from 1998 to 2012, producing up to 10 types of electricity. • We demonstrate that renewable electricity presents better scale of production than non-renewable electricity. - Abstract: To know whether the optimal scale of production has been reached is valuable information for producers. To date, scale efficiency measurements have only been suggested for the entire production process. For multi-output producers, more detailed results are required. Hence, in this paper, we show how to provide such information at the output level. Attractively, our output-specific scale efficiency measurements are nonparametric in nature, they take the economic objective of the producers into account, they can be defined without observing the input prices, and they are easy to interpret and to use in practice. We apply our methodology to a sample of more than 3300 US electricity plants from 1998 to 2012, producing up to 10 types of electricity. We show that, while there is a scale improvement at the total electricity generation level, this is not the case for each of the 10 types of electricity. Also, we demonstrate that, in general, renewable electricity presents better scale of production than non-renewable electricity. Finally, we highlight the importance of multi-output plants in the US electricity sector, and show that this type of plant is preferable for the production of non-renewable electricity, while single-output plants are preferable for renewable electricity.
[en] Extreme isolation, costly and complex logistics, and severe climate are just a few of the extraordinary factors that make power and heat generation a difficult, costly and yet absolutely essential service in northern and arctic Canada. Where an unplanned outage can quickly turn into a life threatening community emergency or major production shut-down, reliability is an absolute must - whatever the cost. This presentation will discuss some of the many exceptional challenges that face power generation in the north, and how the limitations of the current technology employed impedes its customers and indeed all of the north from achieving its full potential. (author)
[en] In this paper, we introduce the concept, design equation, and realization of a broadband electromagnetic vibrational energy harvester. The spatial vibrating system in the proposed harvester is arranged to have three out-of-plane vibration modes. We devise the design method for its three natural frequencies and accompanying modes and apply it to the broadband energy harvesting by locating three frequencies close to each other. The numerical simulation and the experimental results show that it satisfies the designated frequencies as well as the enhanced bandwidth for power generation. (paper)
[en] The United Kingdom was a pioneer in the use of nuclear energy for electricity production, the 4 Calder reactors, commissioned in 1956, were the first in the world to produce electricity at an industrial scale. The interest for nuclear energy in Great Britain declined in the nineties because of 2 main reasons: in may 1995 the British government stopped providing financial help for the construction of new reactors and the availability of new oil and gas resources in UK makes nuclear power less necessary. Now the situation is different, oil fields are declining, the British government has compelled itself to reduce the environmental impacts of electricity generation and all coal-burning power plants will be stopped by 2025. Furthermore the 14 AGR reactors that are still operating will be stopped by 2030 because of graphite block aging. In 2006, Blair's government launched a program for the construction of new reactors. The British liberal approach was to set a clear, predictable regulation framework in order to allow any reactor design to apply fairly. The result is that several companies (EDF Energy, CGN, Hitachi, Toshiba, Kepco...) working on different technologies of reactors (EPR, Hualong, ABWR, AP1000 then APR-1400 respectively) have been interested by the nuclear renaissance in UK. EDF Energy was the first company to take position by proposing to build 2 EPR on the Hinkley-Point site. In 2016 a contract for difference (CfD) was signed, a selling price of 106.72 pounds/MWh is assured for 35 years. Horizon Nuclear Power, a subsidiary of Hitachi, is expected to build 2 ABWR (Advance Boiling Water Reactor) on the Wylfa Newydd site in Wales. A public partial financing has been obtained. EDF and CGN are negotiating with the British government for the construction of 2 EPR on the Sizewell site (Suffolk). In this case the financing is totally private but with a guarantee by the state. Others projects exist but they are less advanced, for instance the Bradwell project involving the construction of Chinese HPR 1000 reactors or the Moorside project in which Westinghouse proposes to build AP1000 reactors. Nuclear energy is also perceived by British authorities as a means to boost a weakening national industry. (A.C.)
[en] Highlights: • We empirically analyze twelve electricity tariffs for residential microgrids. • We calculate that tariffs with volumetric rates would encourage grid destabilization. • We show that capacity charges would moderate the impact of time-varying rates. • We find that a mix of capacity and customer charges would benefit all stakeholders. - Abstract: Increasingly, residential customers are deploying PV units to lower electricity bills and contribute to a more sustainable use of resources. This selective decentralization of power generation, however, creates significant challenges, because current transmission and distribution grids were designed for centralized power generation and unidirectional flows. Restructuring residential neighborhoods as residential microgrids might solve these problems to an extent, but energy retailers and system operators have yet to identify ways of fitting residential microgrids into the energy value chain. One promising way of doing so is the tailoring of residential microgrid tariffs, as this encourages grid-stabilizing behavior and fairly re-distributes the associated costs. We thus identify a set of twelve tariff candidates and estimate their probable effects on energy bills as well as load and generation profiles. Specifically, we model 100 residential microgrids and simulate how these microgrids might respond to each of the twelve tariffs. Our analyses reveal three important insights. Number one: volumetric tariffs would not only inflate electricity bills but also encourage sharp load and generation peaks, while failing to reliably allocate system costs. Number two: under tariffs with capacity charges, time-varying rates would have little impact on both electricity bills and load and generation peaks. Number three: tariffs that bill system and energy retailer costs via capacity and customer charges respectively would lower electricity bills, foster peak shaving, and facilitate stable cost allocation.
[en] The need for the development of the energetics to be based on unified principles and criteria is shown: through the embedding of the processes and objects into the energy fields of the environment; the construction of a structure of the electricity system through energy rings and loops, based on summarized criterion for the evaluation of the level of use of the electrical and thermal energy; construction of an energy strategy in the country of the only energy technology – the one of the green leaf (photosynthesis); reengineering of the production by embedding into the energy space of the environment and construction of energy producing bioenergy systems; energetically technological cascading of the production systems and objects.