Energy wood chips are mechanically shredded wood and it is a climate-friendly, relatively inexpensive and regional fuel for heat and power generation. A distinction is made between fine wood chips, medium wood chips and coarse wood chips with the designations G30, G50 and G100 or more recently via the particle size P16, P31/P45 and P63, they state that the length of the main fraction is 16 mm, 31 mm/s 45 mm or s 63mm. Fine wood chips are particularly suitable for smaller plants and coarse wood chips for large plants.