Biomass is renewable organic material that comes from plants and animals and contains stored chemical energy from the sun. Plants produce biomass through photosynthesis. Biomass can be burned directly for heat or converted to renewable liquid and gaseous fuels through various processes.
Biomass sources for energy include:
- Wood and wood processing wastes
- Agricultural crops and waste materials
- Biogenic materials in municipal solid waste (paper, cotton, and wool products, food, yard and wood waste)
- Animal manure and human sewage
- Fishery byproducts
- Food service byproducts and waste
Throughout history biomass has been an important fuel to humans. Until the mid 1800s biomass was the largest source of total annual U.S. energy consumption. In many developing countries, biomass continues to be an important fuel, especially for cooking and heating. The use of biomass as a fuel for transportation and electric generation is increasing in many developed countries as a means of reducing greenhouse gas emissions. As of 2020, biomass made up approximately 10% of the total world primary energy supply and 70% of world renewable energy supply.