Biomass energy production

Biomass energy comes from organic material — wood, crop residues, dedicated energy crops, animal waste and other plant matter — that can be burned or processed to release the energy it stores. That energy originates with photosynthesis, in which plants capture sunlight to build their tissues, so biomass is sometimes described as a form of stored solar energy. Because new plants can be grown to replace those used, biomass is counted among renewable energy sources alongside solar, wind, hydroelectric and geothermal power.

There are several ways to recover energy from biomass. The simplest is direct combustion, burning wood or agricultural waste to produce heat for buildings or to raise steam that drives a turbine and generates electricity. Other methods convert biomass into more convenient fuels: anaerobic digestion lets micro-organisms break down waste in the absence of oxygen to yield biogas, while fermentation and chemical processing produce liquid biofuels such as ethanol and biodiesel that can power vehicles.

Biomass is often presented as a sustainable option because the carbon dioxide released when it is burned is roughly the amount the plants absorbed while growing, so a well-managed cycle can be close to carbon-neutral over time. In practice the balance depends on how the material is grown, harvested and transported, and on whether land use competes with food production or natural habitats. As one of several renewable technologies — including water wheels and hydro power, wind energy, solar panels and geothermal heat — biomass contributes to reducing reliance on finite fossil fuels.

Frequently asked questions

What counts as biomass?

Organic material such as wood, crop residues, energy crops and animal or food waste, all of which store energy originally captured from sunlight by plants.

How is energy obtained from biomass?

It can be burned directly for heat or electricity, digested by micro-organisms into biogas, or processed into liquid biofuels such as ethanol and biodiesel.

Why is biomass considered renewable?

New plants can be grown to replace those used, and the carbon dioxide released on burning is broadly the amount the plants absorbed while growing.