Cellulosic biorefineries require a stable supply of low-cost feedstock. In this paper we conduct a financial analysis of hybrid poplar as a purpose grown biofuel feedstock. We analyzed growth rates and costs for producing hybrid poplar in the Peace River region of western Canada - an area previously identified as a preferred location for a large biorefinery. We estimated financial returns for two hybrid poplar management systems: (i) a single-stem system that involves the planting and harvesting of individual trees according to optimal economic rotations of 20-26 years, and (ii) a coppice (multi-stem) system that involves multiple harvests of new shoots that sprout from stumps following harvest every 3-4 years. Results suggest that the coppice system is financially inferior (with estimated costs of 202 $ Mg-1) to the single-stem system (with estimated costs of 125 $ Mg-1), largely due to the cost of establishing the high density coppice plantations. But even the single-stem production system does not appear to be financially feasible given the current environment of high land prices and low biomass prices. In contrast to estimated costs of growing poplar, current biomass prices for agriculture and forestry residues are approximately 50 $ Mg-1. However, even though purpose grown energy crops are more expensive than residues, they could be valuable in supplementing a biorefinery's feedstock supply during years when residue yields are low. If governments in Canada wish to encourage renewable energy from cellulosic feedstock, then current economic conditions suggest that subsidies aimed at biomass production are likely required.