This report provides an overview of the challenges associated with the use of renewable feedstocks for producing biofuels, chemicals, and heat or power. These challenges are often related to the inherent properties of the feedstock, requiring pre-treatment before it can be used directly in existing processes. The necessary pre-treatment processes for converting the renewable feedstocks are discussed. The report also summarizes the technology readiness levels (TRL) of the renewable feedstocks and the corresponding cost of pre-treatment.