Many forms of biomass are increasingly used to generate heat for buildings and electricity for power grids. The International Energy Agency (IEA) predicts that all possible forms of renewable energy, including bioenergy, will be needed to completely replace fossil energy. All possible sustainable sources of biomass will therefore be needed; however, biomass comes in many different forms and from many different dispersed locations, complicating this challenge.
According to European legislation (Directive (EU) 2018/2001 on the promotion of the use of renewable energy from renewable sources, ‘biomass’ refers to the biodegradable fraction of products including waste and residues of biological origin from agriculture, (both vegetal and animal), forestry and related industries, fisheries and aquaculture, as well as industrial and municipal wastes. Therefore, substances of biological origin include all plants, crops and their residues that make up the vegetal component of our food supply, non-food animal feed crops, wild plants and vegetation, all components of trees and forest products, seaweed, residues from fishing and animal husbandry (including slurries and manure), as well as all the biodegradable wastes from food production and human sewage. The list is almost endless, but the essential common denominator is the biodegradability of biomass, which contrasts with the most fossil-derived products. The time for biodegradability and regrowth of biomass takes from months to a few decades and it is this relatively short-term cycle that affords biomass is renewable status.Bioenergy is considered in the same legal frame as other renewable energy sources such as solar and wind power and together they contribute to relatively small but growing percentages of energy use in most economies. Increasingly, individual countries are planning fossil-free economies by 2050 in response to the agreed global warming targets (namely the 2017 UNFCCC target to limit a global temperature rise this century to less than 2oC above pre-industrial levels and to make efforts to limit the temperature increase even further to 1.5oC). The current increase in temperature is already close to 1.1oC. All plants – whether food for humans or animals or non-food vegetal biomass – grow by the process of photosynthesis which removes carbon dioxide (CO2) and releases oxygen back into the atmosphere. Biomass growth is vital to ensuring the main way that CO2 is extracted from the atmosphere and in providing environments where biodiversity is maintained.