Biomass was the largest source of total annual U.S. energy consumption until the mid-1800s. In 2023, biomass accounted for nearly 5% of U.S. total primary energy consumption. Biomass is used for heating and electricity generation and as a transportation fuel.
Most electricity generated from biomass is produced by direct combustion. Biomass is burned in a boiler to produce high-pressure steam. This steam flows over a series of turbine blades, causing them to rotate. The rotation of the turbine drives a generator, producing electricity. Biomass can also serve as substitute for a portion of coal in an existing power plant furnace in a process called co-firing (combusting two different types of materials at the same time). Bioenergy, or energy derived from biomass, is a sustainable alternative to fossil fuels because it can be produced from renewable sources, such as plant and woody-mass, that can be continuously replenished.
Biomass is technically a “renewable” energy source, in that trees can be replanted after they’re harvested. And many lawmakers have argued that because trees store carbon as they grow, replacement forests will gradually remove the carbon dioxide emitted when the previous trees were burned for energy, making the whole process carbon neutral—that is, putting no net emissions into the atmosphere. The massive fiscal 2024 federal spending bill includes a provision urging the heads of EPA, the Energy Department and the Agriculture Department to adopt policies that “reflect the carbon-neutrality of forest bioenergy and recognize biomass as a renewable energy source.” In Aril the US Congress approved the Fiscal Year (FY) 2024 spending package that includes language classifying biomass as carbon neutral across federal agencies.