The Latent Potential of Agricultural Residues in Circular Economy: Quantifying their Production Destined for Prospective Energy Generation Applications

Residual biomass from agriculture is a highly promising resource for sustainable energy production. Its abundant generation and accurate estimation are essential for the development and implementation of efficient utilization strategies. However, the calculations proposed in the existing literature are often contradictory or exhibit impractically wide range. This study compiles residual biomass indices for cereal, oil, industrial, and arboreal crops. By evaluating and processing these indices, a refined set of modified indices is presented to enhance existing methodologies for calculating agricultural residues. The methodology establishes lower, average and upper bound scenarios for the residual biomass of selected crops and is applied to Greece to estimate its energy production potential. The findings suggest that Greece generates approximately 5.5 million tons of agricultural residues annually, ranging from 4.5 million tons (lower-bound) to 6.6 million tons (upper-bound). This biomass has the potential to produce 70,730 TJ of energy, corresponding to 8.4% of the country's energy demands, with energy potential ranging between 55,644 and 82,635 TJ. The most noteworthy crops include olive trees, cotton, maize, vineyards and wheat since they account for 82% of the total estimated energy. Spatial analysis conducted at NUTS-2 and NUTS-3 levels highlights the Regions of Central Macedonia and Thessaly as having substantial potential for residual biomass to support energy conversion strategies.