Biomass energy is energy generated or produced by living or once-living organisms. Know all about Biomass Energy , its Sources, Advantages, Disadvantages & Challenges in this article. Learn about biomass , a renewable source of energy derived from plants and animals, and how it can be converted into various fuels and products. Explore the sources, methods, and applications of biomass in the United States and worldwide. Biomass energy is a renewable energy source derived from organic materials like plant residues, agricultural waste, and animal manure. It converts biological matter into electricity, heat, or biofuels.