[hal-01108414] Capacity Mechanisms and Cross-Border Participation: The EU wide approach in question

A capacity remuneration mechanism (CRM) which excludes cross border participants is considered to have serious distortive effects on long term competition, compared to explicit cross border participation (CBP), on the grounds that it doesn’t capture the advantages of multi-system competition. This paper examines the reality of these advantages by distinguishing situations with and without congestion between systems during critical periods because congestion separates markets and their collective goods of reliability and adequacy for each system, and suppresses any economic and physical relevance of a capacity commitment from a new external participant to a CRM. From the limited perspective of any single system, there are two potential advantages of explicit CBP: the first is the supplement of the set of committed capacities to a CRM; the second is the lower cost of the adequacy policy of the system, thanks to enlarged competition, but it is illusory because the clearing price of capacity is the same with and without explicit CBP. Moreover concretization of such benefits for the system is not possible when there is congestion. From the EU wide perspective, we identify some potential gains of social efficiency from explicit CBP at the multi-system level, when we have systems with a long standing situation of overcapacity beside systems with tight situations during their critical periods; or when there exists projects of hydro equipment (pumping storage, etc... But again, congestion removes any sense to any additional revenue to them. In any case erratic revenues certainly do not steer new investment towards either system. Furthermore exchanges of capacity rights between systems equipped with different CRMs introduce a supplement of distortions compared to the same situation with implicit CPB and no trade of capacity rights. It is problematic in the case of congestion; this delays the price signal of capacity scarcity in the system with the least attractive CRM in terms of revenue and risk management.



from HAL : Dernières publications http://ift.tt/1CU7N4q

[hal-01110438] La précarité énergétique dans le transport

[...]



from HAL : Dernières publications http://ift.tt/1JFDxxZ

[hal-01110344] Modélisation intégrée de l'impact de la forme urbaine sur la qualité de l'air : information spatiale, cartographie et prospective

[...]



from HAL : Dernières publications http://ift.tt/1v0dEWN

[hal-01110347] Analyse des impacts de la forme de la croissance urbaine sur la qualité de l'air, Une chaine de modélisation spatiale pluridisciplinaire

[...]



from HAL : Dernières publications http://ift.tt/1JCVXzu

[hal-00800045] Calibration procedures and first dataset of Southern Ocean chlorophyll a profiles collected by elephant seals equipped with a newly developed CTD-fluorescence tags

In situ observation of the marine environment has traditionally relied on ship-based platforms. The obvious consequence is that physical and biogeochemical properties have been dramatically undersampled, especially in the remote Southern Ocean (SO). The difficulty in obtaining in situ data represents the major limitations to our understanding, and interpretation of the coupling between physical forcing and the biogeochemical response. Southern elephant seals (Mirounga leonina) equipped with a new generation of oceanographic sensors can measure ocean structure in regions and seasons rarely observed with traditional oceanographic platforms. Over the last few years, seals have allowed for a considerable increase in temperature and salinity profiles from the SO, but we were still lacking information on the spatiotemporal variation of phytoplankton concentration. This information is critical to assess how the biological productivity of the SO, with direct consequences on the amount of CO2 "fixed" by the biological pump, will respond to global warming. In this research programme, we use an innovative sampling fluorescence approach to quantify phytoplankton concentration at sea. For the first time, a low energy consumption fluorometer was added to Argos CTD-SRDL tags, and these novel instruments were deployed on 27 southern elephant seals between 25 December 2007 and the 4 February 2011. As many as 3388 fluorescence profiles associated with temperature and salinity measurements were thereby collected from a vast sector of the Southern Indian Ocean. This paper addresses the calibration issue of the fluorometer before being deployed on elephant seals and presents the first results obtained for the Indian sector of the Southern Ocean. This in situ system is implemented in synergy with satellite ocean colour radiometry. Satellite-derived data is limited to the surface layer and is restricted over the SO by extensive cloud cover. However, with the addition of these new tags, we are able to assess the 3-dimension distribution of phytoplankton concentration by foraging southern elephant seals. This approach reveals that for the Indian sector of the SO, the surface chlorophyll a (chl a) concentrations provided by MODIS were underestimated by a factor 2 compared to chl a concentrations estimated from HPLC corrected in situ fluorescence measurements. The scientific outcomes of this programme include an improved understanding of both the present state and variability in ocean biology, and the accompanying biogeochemistry, as well as the delivery of real-time and open-access data to scientists (doi:10.7491/MEMO.1x)



from HAL : Dernières publications http://ift.tt/15SDzV6

[hal-01110345] Impact de la structure urbaine sur la consommation énergétique et la qualité de l’air : une approche par modélisation intégrée

[...]



from HAL : Dernières publications http://ift.tt/15GN5tE

[hal-01108949] Le besoin de marchés de la flexibilité : L’adaptation du design des marchés électriques aux productions d’énergies renouvelables

[...]



from HAL : Dernières publications http://ift.tt/1EByEDe

[hal-01092290] Future changes in precipitation and impacts on extreme streamflow over Amazonian sub-basins

Because of climate change, much attention is drawn to the Amazon River basin, whose hydrology has already been strongly affected by extreme events during the past 20 years. Hydrological annual extreme variations (i.e. low/high flows) associated with precipitation (and evapotranspiration) changes are investigated over the Amazon River sub-basins using the land surface model ORCHIDEE and a multimodel approach. Climate change scenarios from up to eight AR4 Global Climate Models based on three emission scenarios were used to build future hydrological projections in the region, for two periods of the 21st century. For the middle of the century under the SRESA1B scenario, no change is found in high flow on the main stem of the Amazon River (Óbidos station), but a systematic discharge decrease is simulated during the recession period, leading to a 10% low-flow decrease. Contrasting discharge variations are pointed out depending on the location in the basin. In the western upper part of the basin, which undergoes an annual persistent increase in precipitation, high flow shows a 7% relative increase for the middle of the 21st century and the signal is enhanced for the end of the century (12%). By contrast, simulated precipitation decreases during the dry seasons over the southern, eastern and northern parts of the basin lead to significant low-flow decrease at several stations, especially in the Xingu River, where it reaches -50%, associated with a 9% reduction in the runoff coefficient. A 18% high-flow decrease is also found in this river. In the north, the low-flow decrease becomes higher toward the east: a 55% significant decrease in the eastern Branco River is associated with a 13% reduction in the runoff coefficient. The estimation of the streamflow elasticity to precipitation indicates that southern sub-basins (except for the mountainous Beni River), that have low runoff coefficients, will become more responsive to precipitation change (with a 5 to near 35% increase in elasticity) than the western sub-basins, experiencing high runoff coefficient and no change in streamflow elasticity to precipitation. These projections raise important issues for populations living near the rivers whose activity is regulated by the present annual cycle of waters. The question of their adaptability has already arisen. © 2013 IOP Publishing Ltd.



from HAL : Dernières publications http://ift.tt/1Jd251c

[hal-01108944] Carbon price instead of support schemes : Windpower investments by the electricity markets

In this paper we study the development of wind power by the electricity market without any usual support scheme which is aimed at subsidizing non mature renewables, with the sole incentive of a significant carbon price. Long term electricity market and investment decisions simulation by system dynamics modelling is used to trace the electricity generation mix evolution over a 20-year period in a pure thermal system. A range of stable carbon price, as a tax could be, is tested in order to determine the value above which wind power development by market forces becomes economically possible. Not only economic competitiveness in terms of cost price, but also profitability against traditional fossil fuel technologies are necessary for a market-driven development of wind power. Results stress that wind power is really profitable for investors only if the carbon price is very significantly higher than the price required for making wind power MWh's cost price competitive with CCGT and coal-fired plants on the simplistic basis of levelized costs. In this context, the market-driven development of wind power seems only possible if there is a strong commitment to climate policy, reflected by the preference for a stable and high carbon price rather than a fuzzy price of an emission trading scheme. Besides, results show that market-driven development of wind power would require a sky-rocketing carbon price if the initial technology mix includes a share of nuclear plants even with a moratorium on new nuclear development.



from HAL : Dernières publications http://ift.tt/1EByFHz

[hal-01108356] Le marché européen et les politiques Climat-Énergie, deux objectifs irréconciliables

[...]



from HAL : Dernières publications http://ift.tt/1y2EeZR

[hal-00544409] Overview of SMOS Level 2 Ocean Salinity processing and first results

SMOS (Soil Moisture and Ocean Salinity), launched in November 2, 2009 is the first satellite mission addressing the salinity measurement from space through the use of MIRAS (Microwave Imaging Radiometer with Aperture Synthesis), a new two-dimensional interferometer designed by the European Space Agency (ESA) and operating at L-band. This paper presents a summary of the sea surface salinity retrieval approach implemented in SMOS, as well as first results obtained after completing the mission commissioning phase in May 2010. A large number of papers have been published about salinity remote sensing and its implementation in the SMOS mission. An extensive list of references is provided here, many authored by the SMOS ocean salinity team, with emphasis on the different physical processes that have been considered in the SMOS salinity retrieval algorithm.



from HAL : Dernières publications http://ift.tt/15SDBwf

[hal-00758785] Vertical Variability of Near-Surface Salinity in the Tropics: Consequences for L-Band Radiometer Calibration and Validation

Not Available



from HAL : Dernières publications http://ift.tt/15O8vVC

[hal-01108443] Carbon price instead of support schemes : Windpower investments by the electricity markets

In this paper we study the development of wind power by the electricity market without any usual support scheme which is aimed at subsidizing non mature renewables, with the sole incentive of a significant carbon price. Long term electricity market and investment decisions simulation by system dynamics modelling is used to trace the electricity generation mix evolution over a 20-year period in a pure thermal system. A range of stable carbon price, as a tax could be, is tested in order to determine the value above which wind power development by market forces becomes economically possible. Not only economic competitiveness in terms of cost price, but also profitability against traditional fossil fuel technologies are necessary for a market-driven development of wind power. Results stress that wind power is really profitable for investors only if the carbon price is very significantly higher than the price required for making wind power MWh's cost price competitive with CCGT and coal-fired plants on the simplistic basis of levelized costs. In this context, the market-driven development of wind power seems only possible if there is a strong commitment to climate policy, reflected by the preference for a stable and high carbon price rather than a fuzzy price of an emission trading scheme. Besides, results show that market-driven development of wind power would require a sky-rocketing carbon price if the initial technology mix includes a share of nuclear plants even with a moratorium on new nuclear development.



from HAL : Dernières publications http://ift.tt/1CkC9yP

[hal-01107944] Axiomatisation of constraint systems to specify a tableaux calculus modulo theories

[...]



from HAL : Dernières publications http://ift.tt/1uu05i0

[hal-01110497] Molecular epidemiology of Toxoplasma gondii.

[...]



from HAL : Dernières publications http://ift.tt/15O8vF8

[insu-01093152] Anchovy population and ocean-climatic fluctuations in the Humboldt Current System during the last 700 years and their implications

A marine sedimentary record collected from 87 m water depth in a coastal environment of the Humboldt Current System (Mejillones Bay, 23° S, northern Chile) was used to reconstruct the past 700 years of ocean-climatic con-ditions and to study the influence of any changes on anchovy population dynamics. We analyzed quartz, organic carbon, total nitrogen, alkenones and fish scales. Four stratigraphic units in the sediment column correspond with fluctuations in these and other proxies. Low Scale Deposition Rate (SDR) values from 1330 to 1420 suggest a low abundance of anchovy in this coastal environment. Three subsequent cycles of ca. 170 years each showed an increase and decrease of anchovy populations, which is in agreement with changes in the wind regime, sea surface temperature and primary productivity. Since ca. 1840, marked fluctuations of SDR have been observed, probably as a consequence of the onset of a different oceanographic regime characterized by intensified southern winds and upwelling, colder surface waters, higher primary productivity, and enhanced "La Niña like" interdecadal variability. An increase of the anchovy population was observed until halfway through the 20th century, followed by a decrease, even though water temperature decreased and primary productivity increased. This situation is likely the consequence of the increased fishery activity that developed in this zone during the last 60 years. After analyzing the results obtained for anchovy SDR, we can determine that there is a relation between the abundance of this species and phases of the Pacific Decadal Oscillation (PDO), in which an increase in the SDR coincides with a PDO cold phase, while a decline coincides with a warm phase. Fast Fourier transformation analysis applied to the time series obtained from the Mejillones sediment core and to the North Atlantic Oscillation (NAO), the PDO, and the solar irradiance index time series shows three different decadal cycles (80–100 years, 61–75 years and 45–48 years approximately). Furthermore, the results of this study suggest that both the PDO and the NAO and the biogeochemical markers of Mejillones exhibit periodicities that fall within the 80 to 100 year Gleissberg solar cycle, indicating that global solar radiation plays a key role in the local ocean-climatic processes and confirming teleconnection linkages between widely separated regions.



from HAL : Dernières publications http://ift.tt/15O8uAS

[hal-01107615] Rice husk gasification for electricity generation in Cambodia in December 2014

Rice husks are the indigestible coatings of grains of rice. They are produced in large quantities by the rice milling industry, more than 1 million ton per year in Cambodia. In recent years, Cambodian enterprises have installed gasifiers, which burn rice husks to generate electricity. This is a two stage process: the biomass is first fed into a gasifier which produces syngas and ashes, then the syngas is cleaned and burned into an engine where it saves diesel fuel. Many of these enterprises have been in local communities currently without electricity or in fuel poverty. To learn more about the benefits and drawbacks of using rice-husk gasifiers, and to study about the sustainability challenges for deploying these technologies, the Clean energy and sustainable development lab (CleanED lab) of the University of Science and Technology of Hanoi (USTH), and the SNV Netherlands Development Organisation (SNV) have conducted a visit of several rice mills and rural electricity enterprises from 18 th to 22nd December 2014. Five rice mills and a rural electricity enterprise in Battambang, Siem Reap and Kampong Thom provinces were selected for the field survey. In addition with desk research, semi-structured interviews with gasifier users, with the representatives of Canadia Bank PLC and the Federation of Cambodian Rice Millers Association (FCRMA) during the field surveys were also conducted. This report present and justifies the main conclusions of the visit.



from HAL : Dernières publications http://ift.tt/15O8ukz

[hal-01108405] Peut-on maîtriser les coûts privés et sociaux du nucléaire ?

[...]



from HAL : Dernières publications http://ift.tt/1t29iNC

[hal-01110495] Linguistique de terrain, méthode et théorie. Une approche ethno-sociolinguistique de la complexité

Cet ouvrage propose aux étudiants-chercheurs, du master au doctorat, une initiation globale, détaillée et approfondie à une démarche de recherche en sociolinguistique, depuis la méthode d’observation des phénomènes sur terrain jusqu’à leur interprétation, grâce à des concepts opératoires essentiels, en passant par des outils d’analyses adaptés. Il propose également aux chercheurs confirmés une synthèse scientifique de l’ensemble d’un courant méthodologique et théorique, dont la caractéristique majeure est d’étudier les phénomènes linguistiques effectifs dans leurs contextes socioculturels et dans toute leur diversité.



from HAL : Dernières publications http://ift.tt/15SDxMS

[tel-01110171] RECHERCHE EXPLORATOIRE DE NOUVEAUX MATERIAUX D’ELECTRODE NEGATIVE POUR BATTERIE SODIUM-ION

Lithium-ion batteries have become essential in recent years. Due to both the difficult access and the cost of the alkaline element, a new field of research concerning sodium-ion batteries has recently emerged. Among the major challenges inherent to this new battery type, the aim of the work developed during this PhD thesis is to explore new negative electrode materials. Two material types have been studied: metallic tin, and the chalcogenides AV4S8 (A=Ga, Ge). Tin was obtained with dense or dendritic form by electrolchemical deposition. In sodium-ion battery, this material presents interesting properties since during the first discharge, a specific capacity of 1 Ah/g at a working potential below 0.6 V relative to Na+/Na0 can be obtained. However, a volume expansion of 350% during the sodiation causes a significant capacity loss, which is under 100 mAh/g after around ten cycles. The AV4S8 chalcogenides (A = Ga, Ge) have been the main subject of this PhD thesis. The reaction mechanism with sodium, close to a conversion mechanism, has been studied by in situ X -ray diffraction, X-ray absorption spectroscopy and electron energy loss spectroscopy in order to observe the oxidation number evolution of the elements involved in the reaction with sodium. These materials exhibit remarkable electrochemical properties, with an initial specific capacity of more than 800 mAh/g at low potential with excellent capacity retention upon cycling.



from HAL : Dernières publications http://ift.tt/1tp6BG7