The degree of technological maturity, economic cost considerations and conversion efficiency strongly influence technology selection decisions when conversion of woody biomass into bioenergy products is undertaken. Conversion efficiencies in particular have a key impact on the overall environmental impact of bioenergy value chains and therefore receive in-depth attention in this regard in Chap. 11, while not being discussed further here. Technology maturity and economic considerations are considered here for each of the thermochemical and biochemical conversion methods presented.