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AbstractDecarbonising the energy system requires high shares of variable renewable generation and sector coupling like power to heat. In addition to heat supply, heat pumps can be used in future energy systems to provide flexibility to the electricity system by using the thermal storage potential of the building stock and buffer tanks to shift electricity demand to hours of high renewable electricity production. Bridging the gap between two methodological approaches, we coupled a detailed building technology operation model and the open-source energy system model Balmorel to evaluate the flexibility potential that decentral heat pumps can provide to the electricity system. Austria in the year 2030 serves as an example of a 100% renewable-based electricity system (at an annual national balance). Results show that system benefits from heat pump flexibility are relatively limited in extent and concentrated on short-term flexibility. Flexible heat pumps reduce system cost, CO2 emissions, and photovoltaics and wind curtailment in all scenarios. The amount of electricity shifted in the assessed standard flexibility scenario is 194 GWhel and accounts for about 20% of the available flexible heat pump electricity demand. A comparison of different modelling approaches and a deterministic sensitivity analysis of key input parameters complement the modelling. The most important input parameters impacting heat pump flexibility are the flexible capacity (determined by installed capacity and share of control), shifting time limitations, and cost assumptions for the flexibility provided. Heat pump flexibility contributes more to increasing low residual loads (up to 22% in the assessed scenarios) than decreasing residual load peaks. Wind power integration benefits more from heat pump flexibility than photovoltaics because of the temporal correlation between heat demand and wind generation.

Cette thèse est basée sur des simulations numériques régionales et aborde, d’un point de vue énergétique, la variabilité à Méso (O(10-100)km) et Sous-mésoéchelle (O(0.1-10)km) dans la région du Courant des Aiguilles.(i) La variabilité de sous-mésoéchelle à la transition entre les deux branches du Courant des Aiguilles (28◦E-26◦E) est dominée, en l’absence de méandres de mésoéchelle, par des tourbillons cycloniques frontaux formant un ‘vortex street’. La tension ambiante frontogénétique intensifie le cisaillement frontal qui déclenche l’instabilité barotrope menant à la génération de tourbillons de sous-mésoéchelle.(ii) Un budget modal d’Energie Cinétique des Tourbillons est développé pour caractériser les transferts d’énergie entre les différentes structures verticales. Les interactions canalisées par la topographie (3 processus) résultent globalement en une perte d’énergie pour les tourbillons de mésoéchelle plus grande que les processus de dissipation (friction au fond et vent) et une cascade verticale inverse (interactions triadiques) renforce les tourbillons de mésoéchelle dans les zones au large.(iii) Notre budget modal permet de caractériser la région du Courant des Aiguilles comme une source nette d’énergie pour les tourbillons de mésoéchelle en contradiction avec celui estimé à partir de données d’altimétrie. Cette différence vient des données d’altimétrie ne tenant pas compte de la contribution principale de la dynamique aux sources et puits d’énergie des tourbillons de mésoéchelle (partie linéaire de la dynamique agéostrophique du mode barotrope et du 1er mode barocline). This dissertation is based on regional numerical simulations and addresses, from an energetic perspective, the Meso (O(10-100)km) and Submesoscale (O(0.1- 10)km) variability in the Agulhas Current region.(i) Submesoscale variability at the transition between the two Agulhas Current branches (28◦E-26◦E) is dominated, in the absence of mesoscale meanders, by cyclonic frontal eddies forming a ’vortex street’. The frontogenetic background strain intensifies the frontal shear which triggers the barotropic instability leading to submesoscale eddies generation.(ii) A modal Eddy Kinetic Energy budget is derived to characterize the energy transfers between the different vertical structures. Interactions canalized by topography (3 processes) globally result in a larger energy loss for mesoscale eddies than dissipation processes (bottom friction and wind) and an inverse vertical cascade (triadic interactions) reinforces mesoscale eddies in offshore areas.(iii) Our modal budget allows to characterize the Agulhas Current region as a net energy source for mesoscale eddies in contradiction with one inferred from altimetry data. The discrepancies come from altimetry data not accounting for the main contribution of the dynamics to mesoscale eddies energy sources and sinks (ageostrophic linear part of the dynamics of the barotropic and 1st baroclinic modes).

In the present study, we explored the temperature evolution and hydrogen desorption properties of the Mg50Ni50 alloy through both numerical simulation and experimental analyses. Desorption kinetics characterization was carried out using the volumetric method, specifically employing a Sievert's-type apparatus to investigate solid-gas reactions. The experiments covered a temperature range from 313 K to 353 K, with an initial hydrogen pressure of 12 bar. Simultaneously, a mathematical approach was employed to numerically investigate the temperature evolution within the hydride bed. Using COMSOL Multiphysics as a simulator, a numerical simulation was conducted based on experimental data. The study examined the impact of cooling temperature on hydride temperature evolution. Results revealed that hydrogen desorption kinetics of the amorphous Mg50Ni50 alloy are more significant compared to those of Mg2Ni compounds. Moreover, the effect of the warming temperature on the equilibrium pressure can also be observed in the hydrogen desorption isotherm curves. The experimental study of the Mg50Ni50 alloy provided activation energy data, along with determination of hydride formation enthalpy and entropy. On the other hand, we showed that the hydride temperature is maximum at the hydride-hydrogen interface within the hydride center.

FAERE Working Paper, 2019.23 ; While environmental values are spreading among societies, theyhardly lead to effective political actions. This may be due to an overestimation of the sharing of those values among people, or to a lack ofpolitical power of environmentalists vis-à-vis materialist citizens. Wepropose a theoretical model to investigate these two channels, based ona setup a la Grossman and Helpman (1994), in which lobby is a strategy available to social groups, in order to influence the government onenvironmental taxes. Because societies have being historically markedby materialist habits, citizens sharing those habits face lower costswhen getting organized. By considering endogenous lobby formation ala Mitra (1999), we show that, in order for environmental and materialist lobbies to coexist, the society must be mixed enough. Based on adynamic framework a la Besley and Persson (2019), we investigate howsocial values change over time. Whenever lobbying by materialists prevails, a unique social equilibrium exists, featuring a stable hegemonyby materialist values. If environmentalists get organized too, a secondsocial equilibrium emerges, that is locally stable and more favorableto them. However, the threshold might be very high, above which thecultural transition effectively takes off. By calibrating the model, westudy counter-acting forces allowing to improve the odds of the environmental transition, such as cultural mutations, social-signaling, andlowering organizational costs. Finally, we provide policy implications. ; Alors que les valeurs environnementales se répandent dans les sociétés, elles ne débouchent guère sur des actions politiques efficaces. Cela peut être dû à une surestimation du partage de ces valeurs entre les gens, ou à un manque de pouvoir politique des écologistes vis-à-vis des citoyens matérialistes. Nous proposons un modèle théorique pour investiguer ces deux canaux, basé sur un cadre à la Grossman et Helpman (1994), dans lequel le lobbying est une stratégie à la disposition des ...

At the 1972 Stockholm Conference, participating States expressed concern about the extent and consequences of air pollution, laying the groundwork for international legal cooperation to address it. The Action Plan for the Human Environment included the need to promote scientific observation of the atmosphere, and the principles set out in the Stockholm Declaration served, as in other areas of environmental international law, to articulate the response to the threats identified. Since that meeting, the evolution of international legal protection of the atmosphere has been marked by the implementation of three international regimes. The European regime on transboundary air pollution, inaugurated in 1979, was the first model of international cooperation in this field, and influenced subsequent developments in the regimes on ozone layer protection and climate change. Taking into account the foundational impetus that the Stockholm Conference provided for the development of these regimes, this paper analyses the evolution of international legal protection of the atmosphere in the fifty years since the Conference was held

With the aim to fully exploit the by-products obtained after the industrial extraction of starch from sweet potatoes, a cascading approach was developed to extract high-value molecules, such as proteins and pectins, and to valorize the solid fraction, rich in starch and fibrous components. This fraction was used to prepare new biocomposites designed for food packaging applications. The sweet potato residue was added to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in various amounts up to 40 wt % by melt mixing, without any previous treatment. The composites are semicrystalline materials, characterized by thermal stability up to 260 °C. For the composites containing up to 10 wt % of residue, the tensile strength remains over 30 MPa and the strain stays over 3.2%. A homogeneous dispersion of the sweet potato waste into the bio-polymeric matrix was achieved but, despite the presence of hydrogen bond interactions between the components, a poor interfacial adhesion was detected. Considering the significant percentage of sweet potato waste used, the biocomposites obtained show a low economic and environmental impact, resulting in an interesting bio-alternative to the materials commonly used in the packaging industry. Thus, according to the principles of a circular economy, the preparation of the biocomposites closes the loop of the complete valorization of sweet potato products and by-products.

This deliverable includes the methodology in EnergyPROSPECTS for an in-depth study of energy citizenship. It features the criteria used for selecting the cases for indepth study, the list of cases selected for in-depth study as well as key research foci and empirical research questions.