To many people, the most familiar forms of renewable energy are the wind and the sun. But biomass (plant material and animal waste) is the oldest source of renewable energy, used since our ancestors learned the secret of fire.
Biomass is a fancy name for material from plants and animals. Some kinds of biomass can be burned to produce energy. One common example is wood.
Biomass contains stored energy. That’s because plants absorb energy from the sun through the process of photosynthesis. When biomass is burned, this stored energy is released as heat.
Burning biomass releases carbon dioxide. However, plants also take carbon dioxide out of the atmosphere and use it to grow their leaves, flowers, branches, and stems. That same carbon dioxide is returned to the air when the plants are burned.
Many different kinds of biomass, such as wood chips, corn, and some types of garbage, are used to produce electricity. Some types of biomass can be converted into liquid fuels called biofuels that can power cars, trucks, and tractors. Leftover food products like vegetable oils and animal fats can create biodiesel, while corn, sugarcane, and other plants can be fermented to produce ethanol.
Until recently, biomass energy supplied far more renewable electricity—or “biopower”—than wind and solar power combined
If developed properly, biomass can and should supply increasing amounts of biopower. In fact, in numerous analyses of how America can transition to a clean energy future, sustainable biomass is a critical renewable resource.
Sustainable, low-carbon biomass can provide a significant fraction of the new renewable energy we need to reduce our emissions of heat-trapping gases like carbon dioxide to levels that scientists say will avoid the worst impacts of global warming. Without sustainable, low-carbon biopower, it will likely be more expensive and take longer to transform to a clean energy economy.