The aim of the current research is to find sustainable pellet resources that are not made from forestry, agricultural materials, or food products. Evaluation has been carried out by experimentally determining the biofuel parameters of two invasive plant species. In comparison to the process of finding a new application, their use in the production of solid biofuel pellets would not require additional investment for the construction of a new pellet production plant. The article’s hypothesis suggests that biofuel parameters for invasive plant species are sufficient for the production of solid biofuel and that their properties can be improved by binders that are available worldwide in the form of residues. The experiment was carried out for two invasive plant species that are widespread in Latvia – Heracleum sosnowskyi Manden and Solidago canadensis L. The binders used include potato peel waste and spent coffee grounds. All of the tests have been carried out according to ISO standards on biofuel testing. Results show that H sosnowskyi is more suitable for solid biofuel than S canadensis as it has a higher calorific value and an ash content that is two times lower – 3wt%. Coffee grounds are a suitable binder because they increase calorific value. The type and amount of binders partly confirms the hypothesis, since both binders reduced the amount of ash in pellets. Further research is needed to carry out pellet durability tests. It is also necessary to carry out an economic analysis in order to evaluate how beneficial it may be to use H sosnowskyi as a solid fuel in existing pellet production plants, thereby avoiding large initial investments and not encouraging the cultivation of invasive plant species.