The International Food Policy Research Institute has published a series of briefing papers on bioenergy, the opportunities it affords and the challenges it poses. The focus of the papers spans both the developed and the developing world. See Hazell P and Pachauri RK (eds.) (2006). Bioenergy and Agriculture: Promises and Challenges, IFPRI, 2020 Focus No. 14. The paper may be downloaded here. (This is a pay service.)