This thesis investigates the opportunities and challenges of using repurposed electric car batteries, so called Second-life Battery (SlB), in a residential building as an energy storage. The performance of SlBs is compared to a First-life Battery (FlB) by identifying two potential scenarios and using a battery degradation model. The first scenario involved the batteries providing ancillary services to the grid, while in the second scenario the batteries were used for peak shaving. The battery degradation model is based on typical usage from the scenarios. The thesis findings indicate that the SlB degrades at a slower rate than the FlB, but can perform fewer cycles. Economic performance varies based on the application and initial assumptions. Both batteries proved to be profitable in the two scenarios studied, with some of the SlB configurations outperforming FlB configurations and vice versa. The yearly compensation received, when providing ancillary services with a 1000 kWh battery, ranged between 3-8 MSEK, while the yearly compensation received, when peak shaving with a 200-300 kWh battery, ranged between 20-35 thousand SEK. The main challenges identified included reduced lifespan, security risks, potential price increases, and space constraints. On the other hand, the main opportunities identified included potential price decreases and sustainability benefits such as carbon footprint reduction and grid stability. These results may provide valuable insights for informed decision-making regarding investments in FlBs and SlBs on the Swedish market.

Nous avons proposé dans cette thèse une nouvelle approche de modélisation des réponses cellulaire et tumorale durant la radiothérapie. Cette modélisation est fondée sur les chaînes de Markov. Elle se situe dans le cadre de la théorie de cible qui suppose qu'il existe dans la cellule des régions sensibles appelées cibles, qui doivent toutes être désactivées pour tuer la cellule. Un premier travail est consisté à proposer un modèle à temps discret en tenant compte non seulement des phases de réparations cellulaires entre les fractions de dose mais également de l'hétérogénéité des dommages cellulaires.Nous avons ensuite proposé un modèle stochastique de la durée de vie cellulaire. Cette modélisation fut également étendue à une population de cellules et a permis d'établir de nouvelles expressions des probabilités d'efficacité et de complication thérapeutique. Nos derniers travaux portent sur le développement d'un modèle de type chaîne de Markov à temps continu qui pourrait être appliqué aux réponses des tumeurs traitées par la thérapie photodynamique / In this thesis, we have proposed a Markov chain modeling of the cell and tumor behaviors during radiotherapy. Our approach is based on the target theory where it is assumed that the cell contains a number of sensitive sites called targets which must be all deactivated to produce the cell death. A first task was to provide a discrete-time model taking cell repair between dose fractions and the heterogeneity of cellular damage into account. Then, we proposed a stochastic model of the cell lifespan. This model was also extended to a cell population and allowed to derive new expressions of the efficiency and complication probabilities of the treatment. Finally, we focused on the development of a model based on Markov chain in continuous time which could be applied to the responses of tumors treated by photodynamic therapy