The coal-fired power station at Saint-Avold in eastern France is preparing to switch to biomass: huge piles of coal, ready for winter, now sit alongside a more modest pile of wood pellets. "We are switching to renewable energy. We're no longer polluting with CO2, tonnes of CO2," says Sylvain Krebs, head of the coal park at GazelEnergie, which owns the plant. IMAGES AND SOUNDBITES