Biomass

Fast Facts About
Energy from Biomass

Principal Energy Uses: Transportation, Electricity, Heat
Form of Energy: Chemical

Biomass is a semi-renewable energy resource that comes from plants and animals. We categorize this resource as semi-renewable because it has to be carefully managed to ensure we are not using it faster than it can be replenished. Biomass contains stored chemical energy from the sun that is produced by plants through photosynthesis. Biomass can be burned directly for heat or converted to liquid and gaseous fuels through various processes. Liquid biofuels and biogas are energy carriers, or currencies, that are easier to use, transport, and store.

Humans have been using biomass for heating, cooking, and lighting, for thousands of years. About 30% of the world’s population (2.4 billion people) still use “traditional” biomass by gathering wood, peat, or animal waste to burn for cooking and heating. It is simple to store, but not very energy dense, and results in severe indoor air pollution with significant human health effects (3.2 million deaths in 2020). Traditional biomass provides ~7% of total end-use energy consumed worldwide. Energy statistics generally exclude traditional biomass, because it is not bought and sold, making it difficult to track.

In contrast, the International Energy Agency labels “modern bioenergy” as commercial biomass that provides heat and electricity in homes, businesses, and industry, as well as liquid fuels for transportation. Modern bioenergy accounts for ~6% of total end-use energy consumed worldwide.

Biomass can be divided into three categories:

1. Solid Biomass (energy resource)—woody material, crops, municipal solid waste (MSW), and animal and agricultural waste that can be directly burned to produce heat or to generate electricity.
2. Liquid Biofuels (energy currency)—primarily ethanol and biodiesel—come from processing plant matter or waste such as cooking oil into substitutes for traditional vehicle fuels, including gasoline for automobiles, diesel for trucks and ships, and jet fuel for planes (see our Gasoline, Diesel, Jet Fuel, etc. page for more information).
3. Biogas (energy currency)—also known as biomethane—can be collected from decomposing plants, animal manure, human sewage, and municipal solid waste, and burned for heat and electricity generation.

Advocates for biomass argue it is carbon neutral because the carbon released during combustion was originally pulled from the atmosphere during photosynthesis, but the story is more complicated. Depending on the production process, some types of bioenergy increase greenhouse gas emissions, though using waste streams for bioenergy reduces climate and environmental impacts.

There are two main ways to use waste streams from municipalities (Municipal Solid Waste, MSW) for energy. Waste-to-energy incineration plants are the most common because of the amount of electricity they generate, their capacity to reduce the volume of waste, and lower capital investment, but they can have significant air pollution impacts. The second option is to capture the methane emissions from decomposing biomass in landfills or sewage treatment plants and burn that for heat and/or electricity generation. This cleaner-burning option reduces methane emissions to the atmosphere. Bioenergy from waste has had significant growth in Asia, especially in China, in the last decade.

Note: The data in the charts below does not include traditional biomass.