[en] The author proposes a rather radical critical analysis of the NegaWatt scenario which is mainly based on the development of the use of solid and liquid biomass produced by forests and farms, and of some marginal resources like wood and urban wastes. He shows that wood resources in France are not sufficient as part of the wood is used for construction. A further exploitation of wood would lead to a dramatic increase of costs. He shows that the scenario overestimates the available wood in France, and moreover, that the promoters of the scenario overstep the physical, biological, social and economic limits of the real world of agriculture