Wind power, solar photovoltaic cells, solar collectors and new ways of using biomass are, thus, now beginning to make inroads on the energy market, as demonstrated by double-digit growth rates in the 1990s. Indeed, wind power shows an explosive growth similar to that of mobile phones. Whereas much of the demand for these “newer” renewables is linked to public procurement policies or subsidies, they are clearly improving their price/performance and their competitiveness with respect to fossil fuel and nuclear power. However, we are still at a very early stage of diffusion. The accumulated stock of wind turbines, solar collectors and solar photovoltaic cells supplied about 20 TWh in 1996 or 0.04 per cent of total primary energy supply in the OECD. A significant alteration of the vast energy system in the direction of using more renewable energy technologies is going to be a slow, painful and highly uncertain process.