Showing papers by "Adrian Ilinca published in 2008"

Energy storage systems—Characteristics and comparisons

Abstract: Electricity generated from renewable sources, which has shown remarkable growth worldwide, can rarely provide immediate response to demand as these sources do not deliver a regular supply easily adjustable to consumption needs. Thus, the growth of this decentralized production means greater network load stability problems and requires energy storage, generally using lead batteries, as a potential solution. However, lead batteries cannot withstand high cycling rates, nor can they store large amounts of energy in a small volume. That is why other types of storage technologies are being developed and implemented. This has led to the emergence of storage as a crucial element in the management of energy from renewable sources, allowing energy to be released into the grid during peak hours when it is more valuable. The work described in this paper highlights the need to store energy in order to strengthen power networks and maintain load levels. There are various types of storage methods, some of which are already in use, while others are still in development. We have taken a look at the main characteristics of the different electricity storage techniques and their field of application (permanent or portable, long- or short-term storage, maximum power required, etc.). These characteristics will serve to make comparisons in order to determine the most appropriate technique for each type of application.

Wind turbine performance under icing conditions

Abstract: The wind energy market is in full growth in Quebec but technical difficulties due to cold climate conditions have occurred for most of the existing projects. Thus, icing simulations were carried out on a 0.2 m NACA 63 415 blade profile in the refrigerated wind tunnel of the Anti-icing Materials International Laboratory (AMIL). The shapes and masses of the ice deposits were measured, as well as the lift and drag forces of the iced profiles. Scaling was carried out based on the 1.8 MW–Vestas V80 wind turbine technical data, for three different radial positions and two in-fog icing conditions measured at the Murdochville wind farm in the Gaspe Peninsula. For both icing events, the mass of ice accumulated on the blade profile increased with an increase in the radial position. In wet regime testing (first icing event), glaze formed mostly near the leading edge and on the pressure side. It also accumulated by run-off on the trailing edge of the outer half of the blade. In dry-regime testing (second icing event), rime mostly accreted on the leading edge and formed horns. For both icing events, when glaze or rime accreted on the blade profile, lift decreased and drag increased. A load calculation using the blade element theory shows that drag force on the entire blade becomes too large compared to lift, leading to a negative torque and the stop of the wind turbine. Torque reduction is more significant on the outer third of the blade. Setting up a de-icing system only on the outer part of the blade would enable significant decrease of heating energy costs. Copyright © 2007 John Wiley & Sons, Ltd.

Investigation des différentes alternatives renouvelables et hybrides pour l'électrification des sites isolés : rapport interne

Abstract: Dans la plupart des regions isolees, le generateur diesel est la source principale d’energie electrique. Pour ces regions, le prix d’extension du reseau electrique est prohibitif et le prix du combustible augmente radicalement avec l’isolement. La baisse continue des prix des generateurs bases sur l’energie renouvelable et la fiabilite croissante de ces systemes ont mene a une plus grande utilisation des sources d’energie renouvelable pour la generation d’energie electrique dans les regions isolees. Une des proprietes qui limite l’utilisation de l’energie renouvelable est liee a la variabilite des ressources. Les fluctuations de la charge selon les periodes annuelles ou journalieres ne sont pas forcement correlees avec les ressources. Pour les regions isolees, la solution a retenir est certainement le couplage entre plusieurs sources, par exemple des eoliennes, des panneaux photovoltaiques et des generatrices diesel. Apres avoir presente les problematiques des sites isoles et des generatrices diesel, nous presentons la definition et la mission d’un systeme hybride d’energie (SHE) ou nous nous interessons a l’etat de l’art, en particulier relatif aux sources d’energie qui composent ces systemes habituellement. Nous decrivons ainsi les differentes solutions technologiques permettant d’exploiter les ressources renouvelables en site isole, ainsi que les moyens de dimensionnement du SHE. Quelques problemes de fonctionnement et les strategies de commande habituelles du SHE seront presentes aussi.