Today, about 1,800,000 m3 of waste wood are generated on the Swiss territory. With the decision of the Federal Council to phase out nuclear energy in the medium term, new energy source need to be found to compensate the shortfall of electricity production without compromising the GHG emission reductions targets. The aim objective is to assess the long term waste wood potentials for the energy generation and climate change mitigation in Switzerland in the span of a century. The evaluation method relied on a modelling by material flow analysis (MFA) of the metabolism of wood and waste wood in the Swiss anthroposphere. The results reveal that waste wood will stays a limited energy source for the electricity generation but a significant secondary feedstock to meet the energy generation targets from the bioenergy. The heat production from waste wood has the potential to become a significant energy source to answer to the heating district demand. Thus, the relevance of the energy recovery of waste wood lies in its ability to substitute the fossil energy sources for heat demand.