Anything that is or has once been alive is biomass. Logs, cows, trees, plywood, cotton shirts and leaves are examples of biomass. Rocks, frying pans, air, windows and water are not.
An energy resource derived from organic matter. These include wood, agricultural waste and other living-cell material that can be burned to produce heat energy. They also include algae, sewage and other organic substances that may be used to make energy through chemical processes.
Biomass is organic matter available on a renewable basis. Biomass includes forest and mill residues, agricultural crops and wastes, wood and wood wastes, animal wastes, livestock operation residues, aquatic plants, fast-growing trees and plants, and municipal and industrial wastes.