Biomass is the oldest form of energy. For thousands of years man has burned wood to use for heating and cooking. In fact, wood was the biggest energy provider in the world until the mid- 1800s.

Biomass is any organic matter that can be used as an energy source. Organic means anything that is alive or was alive a short time ago. Organic materials are also renewable energy sources. They include trees, plants and animal waste.

Biomass gets its energy from the sun through a process called photosynthesis. Plants such as trees, crops and grass absorb and store the sun's radiant energy in their leaves and roots. The plants then convert this energy into chemical energy in the form of sugar which is a carbohydrate. When people and animals eat plants (biomass) or products made from plants such as wheat, they are using the carbohydrates for energy. When we burn wood (biomass), we use the energy created to make heat.

Garbage is another energy source. It can be burned to generate steam and electricity. Power plants that use garbage and other waste are called waste-to-energy plants.