The biomass of nineteen Populus spp. clones was measured and characterized as a feedstock for energy production. Biomass yield was estimated using the average volume and dry weight of each clone. Quality traits analyzed include higher heating value (HHV) and chemical composition. Biomass yield ranged between 0.31 and 9.54 kg individual(-1). HHV ranged between 17.69 and 20.75 MJ kg(-1). Total extractives varied between 11.78% and 19.62% (mass fraction% on dry basis), Klason lignin ranged between 14.31% and 20.92% and alpha-Cellulose ranged between 42.38% and 48.70%, both without extractives. The ash content ranged from 2.05% to 3.40%. The chemical composition of the clones reported here is slightly different to the previously reported for this genre, but this is attributed to the juvenile wood and the inclusion of bark in the samples. As a result of the biomass used in this study, the correlations between the chemical composition and extractives content on HHV are of very poor quality. Based on our results, an approach including both biomass yield and quality is required in order to ensure the most viable treatment for a sustainable utilization of the biomass for energy generation. For a direct combustion perspective, the preferred clones are those which a high combination of yield and heating value as Bocalari, Beaupre, Constanzo and Nmdv. (C) 2015 Elsevier Ltd. All rights reserved.