Biomass is a general term for biological material that is used for the purpose of energy production. This resource can come in a variety of forms such as woody materials, grasses, solid waste, biogas (methane), ethanol, and biodiesel. Every time you go to the pump to fill up your vehicle, a certain percentage of the fuel comes from ethanol, a biomass energy product from corn or cane sugar. Some vehicles even have the ability to run on 100% ethanol. Your fireplace at home and a certain percentage of the natural gas that heats your home comes from a biomass source.
Biomass energy is stored in the form of glucose through the process of photosynthesis. Photosynthesis the biological process of converting sunlight, carbon dioxide, and water into glucose and oxygen.
The image above illustrates the chemical structure of glucose as it is found in biomass energy sources. Glucose and other organic molecules in their fibrous forms can be converted to other usable forms such as methane, ethanol, or biodiesel, rather than being combusted directly. Methane can be captured as a biogas from a landfill or manure digester. Ethanol can be created through the process of fermentation. Biodiesel is made by combining various vegetable oils or animal fats with alcohol.
When heat is applied to these refined chemicals, the bonds between the carbon and hydrogen are broken and energy is released. This energy can be used to generate steam to heat a building or power a generator.
Along with wind, solar, hydro power, and many others, biomass is considered a renewable energy source. The plants that are used to make biomass can quickly be regrown to be harvested for energy. Additionally, biomass is often seen as a byproduct of industrial processes and can have high value as “waste” energy source.
Unlike other renewable sources such as wind and solar power, biomass can be used as a base load operation of heating and electric power generation. This means that without a high capacitance to store energy, wind and solar power are only useful when the sun is shining and the wind is blowing. Biomass, however, can be stored in high volume and its use can be adjusted as demand for heating or power changes.