Bioenergy Potential of Spring Oat (Avena sativa L.) Cultivars and Gene Bank Accessions from Europe and the United States: Chemical Composition and Calorific Properties

The physicochemical properties and energy potential of grain from 77 spring oat cultivars and gene bank accessions were evaluated using proximate and elemental analyses, as well as measurements of heat of combustion and higher heating value (HHV). The samples exhibited high and relatively stable energy potential. Heat of combustion ranged from 19,262 to 20,429 kJ·kg−1, with a very low relative standard deviation (RSD) of 1.2%, indicating minimal variation in chemical energy content. The maximum HHV reached 17.69 MJ·kg−1 and also showed limited variability among cultivars and accessions. Hierarchical cluster analysis identified four distinct groups containing 8–30 cultivars and accessions each, based on 10 examined properties. Although significant differences in mean values were observed between clusters (except for carbon content), the overall variation among the samples analyzed remained low. Notably, all samples were characterized by very low chlorine concentrations (0.008–0.023% DM), which is advantageous for energy applications. The results confirm that oat biomass is a valuable renewable energy resource and that its calorific value is closely linked to chemical composition. However, the relatively small differences among cultivars and accessions suggest that identifying genotypes with exceptionally high energy potential may be difficult.