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[en] In recent years, annual electricity consumption in France amounted to around 470 TWh, 90% being decarbonized; at the same time, oil and natural gas consumption has been around 900 TWh and 450 TWh respectively. At present, electricity accounts for only a quarter of energy consumption. Energy savings alone will not be enough to move away from oil and natural gas: as equally anticipated for Germany and Great Britain, French reliance on electricity will have to increase significantly to replace oil and gas consumption. Various recent projections underestimate this growth. However, erroneous assumptions would affect the security of our energy supply and the daily life of the French people; the impacts on the cost of electricity and energy in general, and on the competitiveness of our economy would be considerable. In this position paper, the National Academy of Technologies of France (NATF) proposes a reasonable assessment of electricity demand in 2050. It points out that the European electricity system will be more vulnerable in coming years. It proposes some principles for the choice of economic data to be used in optimisation models. On the basis of these elements, it highlights some key points for managing change in the electricity system.
[fr]La consommation annuelle d'electricite en France a ete d'environ 470 TWh, decarbonee a plus de 90%; dans le meme temps, les consommations de petrole et de gaz naturel ont ete respectivement d'environ 900 TWh et 450 TWh. L'electricite ne represente aujourd'hui que le quart de la consommation d'energie. Les seules economies d'energie ne suffiront pas a sortir du petrole et du gaz naturel: comme le prevoient egalement l'Allemagne et la Grande-Bretagne, le recours a l'electricite en France devra croitre significativement pour se substituer aux consommations de petrole et de gaz. Diverses estimations recentes sous-estiment cette croissance. Or des anticipations erronees affecteraient la securite de notre approvisionnement energetique et la vie quotidienne des francais; les impacts sur le cout de l'electricite et des energies en general, et sur la competitivite de notre economie seraient majeurs. Dans cet avis, l'Academie des technologies propose une evaluation raisonnable de la demande d'electricite en 2050. Elle rappelle que le systeme electrique europeen sera plus fragile dans les prochaines annees. Elle propose quelques principes pour le choix des donnees economiques a retenir dans les optimisations. A partir de ces elements, elle souligne quelques points clefs de la conduite du changement du systeme electrique.
[en] The DEMO heat transfer and the power conversion systems (PCS) are both part of DEMO Balance of Plant (BOP). Since a tokamak operates in pulsed mode, a concept using an internal thermal energy storage system was elaborated to allow for flexible operation of the power plant also under dwell time conditions. As part of the Power Plant Physics and Technology (PPPT) conducted by the EUROfusion Consortium for the development of fusion energy, the balance of plant develops the necessary systems and interfaces to relevant DEMO systems to allow efficient energy production. This includes design adaptation and safety analyses in order to identify safety provisions to address issues not acceptable to licensing authorities. As an example, the proposed safety provisions for the integrity of the vacuum vessel (VV) are given. An outlook summarizes design development and safety investigations. (author)
[en] After a brief presentation of '100 pc renewable' scenario adapted from of RTE scenario (the French 'Watt scenario') which already comprised an important share of renewable energy, the author discusses the various means to be implemented to ensure between 410 and 570 TWh/year with a 100 pc renewable mix, and the direct contribution of hydrogen storage/de-storage. He discusses whether it will be possible to operate grids with few or none synchronous machines. He proposes an assessment of already practicable mixes which are based on a storage using synthetic gases, and finally discusses the possible contributions of high efficiency energy storage means
[en] The next few decades will see a profound energy transformation throughout the world. By the end of the century (and perhaps sooner), we will shift from fossil fuel dependence to rely primarily on renewable sources like solar, wind, biomass, and geothermal power. Driven by the need to avert catastrophic climate change and by the depletion of easily accessible oil, coal, and natural gas, this transformation will entail a major shift in how we live. What might a 100% renewable future look like? Which technologies will play a crucial role in our energy future? What challenges will we face in this transition? And how can we make sure our new system is just and equitable? In this book, the authors explore the challenges and opportunities presented by the shift to renewable energy. Beginning with a comprehensive overview of our current energy system, the authors survey issues of energy supply and demand in key sectors of the economy, including electricity generation, transportation, buildings, and manufacturing. In their detailed review of each sector, the authors examine the most crucial challenges we face, from intermittency in fuel sources to energy storage and grid redesign. The book concludes with a discussion of energy and equity and a summary of key lessons and steps forward at the individual, community, and national level. The transition to clean energy will not be a simple matter of replacing coal with wind power or oil with solar; it will require us to adapt our energy usage as dramatically as we adapt our energy sources. Our Renewable Future is a clear-eyed and urgent guide to this transformation that will be a crucial resource for policy-makers and energy activists
[en] Phase change material (PCM) can store large amount of thermal energy at phase change temperature. Determination of thermophysical properties of PCM plays an important role in estimation of energy stored or released in storage device. Properties of PCM are key factors for designing a latent heat thermal energy storage system. This paper deals with the study of effect of heating/cooling rate on thermophysical properties, especially on melting temperature and latent heat of fusion /solidification. Results indicate that latent heat of fusion has more dependence on heating/cooling rate than onset, peak and end temperature. (author)
[en] With the important development of off-shore wind energy (22 GW in 2019, 70 GW in 2030), wind farms always further from coasts, comes the issue of the way to manage the surplus or to regulate electric power production. This article briefly comments the assessment of an envisaged technology which has been developed by a German research institute: the use of concrete spheres, immersed and equipped with a pump/turbine to create a pumped storage power station. A model at a one third scale is about to be built
[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] This article briefly describes how the German Naturspeicher company (a subsidy of the Max Boegle Wind group) combines wind energy production and hydraulic storage in order to optimise electric power production in terms of flexibility, efficiency and storage. The developed installation (in Galidorf, Germany) is briefly described. The whole installation is able to reach an efficiency increased by 25 pc
[en] In accordance with French legislation, each year RTE drafts and publishes the 'Generation Adequacy Report' concerning the supply-demand balance of electricity. As a diagnostic reference for security of supply and of the electric network, the report is a key corporate exercise which is used to shed light on the medium to long term forecasts for security of supply, and therefore to develop national energy policies. This 2019 report presents: 1 - The Generation Adequacy Report as a reference document about the security of supply in France; 2 - The relative stability of the French consumption which may continue into the medium term; 3 - The supply in France: a key moment for the energy transition with many uncertainties; 4 - Europe: a refined representation taking into account the energy policies and the exchanges between countries; 5 - The supply-demand balance diagnosis; 6 - Sensitivity to alternate configurations in France and in Europe; 7 - Action-levers; 8 - Characteristics of a power system in transition; 9 - Appendixes: installed parks and balance sheets
[en] The publication of the Multi-annual Energy Programming (Programmation Pluriannuelle de l'energie - PPE) on 12 April 2020 confirms the importance of the wind industry, both onshore and offshore, in France's energy transition strategy. The objectives are ambitious, involving the doubling of the installed capacity for onshore wind power by 2028 and launching a call for tenders for offshore wind each year at a rate of around 1 GW per year. The health crisis we have just undergone demonstrates that this is a smart move. The production of renewable electricity remained at very high levels during this period, which was out of the ordinary in more than one respect. For wind power, the average coverage rate was 8.8% during the first semester, and even reached 31% in May. The crisis provided an early demonstration of the capacity of renewable energies to contribute to securing the power supply, in addition to their favourable impact on climate change. We are therefore further fortified in determination to extensively develop renewable energies in order to achieve the ambitious objectives of the multi-annual energy programming. The industry also demonstrates that the energy transition is a source of employment, with an 11% increase in wind jobs in 2019. There are currently 20,000 people working in the industry. It also benefits regional economic development by allowing decentralized power generation close to citizens. Thanks to the provisions in favour of participatory engagement carried by the government, communities and citizens are now more involved in wind projects.