Accueil > Actualités > Séminaires > Séminaire d'Axel Kleidon


Titre : Solar, wind, and waves: Natural limits to renewable sources of energy within the Earth system
Nom du conférencier : Axel Kleidon
Son affiliation : (MP Jena)
Laboratoire organisateur : LSCE
Date et heure : 23-11-2016 11h00
Lieu : LSCE - Orme des Merisiers - Bâtiment 701 - Salle 17C
Résumé :

Renewable sources of energy, such as solar, wind, wave, or hydropower, utilize energy that is continuously generated by natural processes within the Earth system from the planetary forcing. Here we estimate the limits of these natural energy conversions and the extent to which these can be used as renewable energy sources using the laws of thermodynamics. At most, wind power in the order of 1 000 TW (1 TW = 1E12 W) can be derived from the total flux of incoming solar radiation of 175 000 TW, which is consistent with estimates based on observations. Other generation rates that are derived from the kinetic energy of wind are in the order of 10 - 100 TW. In comparison, the human primary energy demand of about 17 TW constitutes a considerable fraction of these rates. We provide some further analysis on the limits of wind power using a combination of conceptual models, observational data, and numerical simulation models. We find that many current estimates of wind power substantially overestimate the potential of wind power because the effect of kinetic energy extraction on the air flow is neglected. We conclude that the only form of renewable energy that is available in substantial amounts and that is associated with minor climatic impacts is solar power.

Axel Kleidon studied physics and meteorology at the University of Hamburg (Germany) and Purdue University (USA). He received his Ph.D. in 1998 in meteorology from the University of Hamburg. After his PostDoc at Stanford University he joined the faculty of the University of Maryland in 2001. Since 2006 he leads an independent research group at the Max-Planck-Institute for Biogeochemistry in Jena, Germany. In his research, he uses thermodynamics to quantify natural energy conversions within the Earth system and their limits, and applies this approach to understand atmosphere-biosphere interactions, Earth system responses to global change, and the natural limits of renewable energy.

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