The process of producing energy from biomass is a chain of interlinking stages (fuel supply, energy conversion, energy utilization, residue disposal or recycling), which are mutually dependent. Within this chain, the purpose of ‘fuel supply’ is to produce a biomass fuel from various biomass resources that meets the requirements of the combustion plant with regard to fuel quality (e.g. moisture content, particle size, ash content) and fuel costs (see Figure 3.1). This chapter provides information on the physical options available for fuel supply, pre-treatment and storage. For thermochemical conversion routes of biomass fuel treatment (such as flash pyrolysis, hydrothermal upgrading, gasification, carbonization, etc.), the reader is referred to Chapter 2 and the other tasks in the IEA Bioenergy Agreement (see www.ieabioenergy.com).