Current methods of ranking and selecting biomass fuels are based on short lists of factors. The objective of this thesis is to develop and demonstrate a fuel ranking tool. Existing fuel decision methods and bioenergy technology are reviewed. A fuel ranking tool is then developed and demonstrated. Finally, a procedure for evaluating the thermal efficiency of a pellet stove bioenergy system is developed and implemented. The tool is designed to be applied by an engineer working in cooperation with the actual fuel user. The user identifies a list of all available fuels which are compatible with their specific energy system. The ranking tool is suitable for users of any sized bioenergy system used for space heating, processing heating, or electricity generation. Through effective communication the engineer lists the user’s performance requirements. Requirements considered in this thesis are economic cost of fuels, required storage space, combustion equipment cleaning, and air pollutants emitted during biofuel combustion. Performance indicators corresponding to the user’s requirements are then selected or developed by the engineer. Data is then collected by the engineer to be used for the evaluation of these indicators. The indicators are then combined using weighting factors by the engineer to assign a single numerical score to each fuel. These scores allow the fuels to quickly and easily be ranked by the user according to how well they satisfy the user’s requirements. The ranking tool is demonstrated by applying it to a situation of a pellet stove user with 3 available fuel types. The three fuels are ranked in terms of their ability to satisfy the user’s requirements with respect to economic cost, storage space, equipment cleaning, certain air pollutant emissions, and supporting the local economy. A pellet stove thermal efficiency evaluation method is used to determine the percentage of fuel heating value delivered as space heat to the room housing the stove. Natural and forced convection as well as radiation heat ...