Science
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is Biogas Energy?

Robert Grimmick
Robert Grimmick

Biogas energy is a renewable form of energy produced from decaying organic material. Biogas can be captured from a variety of sources from cow manure to landfill waste. Energy provided by biogas can be used to provide heat, generate electricity, or fuel vehicles. Biogas energy has been used in both developed and developing nations, and may help reduce greenhouse gas emissions, although it does present some disadvantages.

This form of energy is created when bacteria and other microorganisms break down and eat organic material in the absence of oxygen, a process known as anaerobic digestion. While anaerobic digestion is a natural phenomenon, man-made devices known as digesters are used to optimize the results. The exact makeup of the gas varies depending on the material and type of digester, but the primary gas is generally methane, a potent greenhouse gas.

Some farmers use biogas from pig manure to power their farms.
Some farmers use biogas from pig manure to power their farms.

Biogas energy can be produced from many different types of organic material. In the U.S., some farmers use biogas from cow or pig manure to power their farms, and even sell extra electricity to utility companies. In Europe, North America, and other parts of the world, landfill gas that could otherwise cause pollution is captured and used to generate power.

Once purified, biogas can be injected directly into existing natural gas pipelines.
Once purified, biogas can be injected directly into existing natural gas pipelines.

In developing nations like China and India, biogas energy is used by small farms and households for heating and cooking. The digesters can be fed with anything from household waste to sewage, which can improve sanitary conditions in areas where modern infrastructure is unavailable. In addition, the anaerobic digestion process can produce a compost-like sludge that makes a good fertilizer.

Methane also happens to be the primary component in natural gas; with a little purification, biogas energy can supplement or replace fossil fuels without new infrastructure or equipment. Once purified, biogas can be injected directly into existing natural gas pipelines. This allows biogas, sometimes known as biomethane in its upgraded form, to be used in natural gas power plants. It also means that cars and trucks designed to run on natural gas can use biogas as fuel.

Biogas can also be used in carbon offset programs. In many cases, producers of biogas energy burn methane and other greenhouse gases that would otherwise be released into the atmosphere. In addition to earning income from power generation, these producers, whether a single farmer or a large company, can sell carbon credits to electric utilities and other companies.

As with all sources of energy, biogas does have drawbacks. Although it may reduce greenhouse gas emissions, biogas is not entirely free of pollution. Since a digester is designed to be hospitable to bacteria, there is a potential for the growth of dangerous microorganisms. Methane is explosive, and precautions must be taken when handling or transporting it. Still, the many advantages of biogas energy nay mean its use is likely to continue increasing throughout the world.

Discussion Comments

Glasshouse

It seems like biogas energy would be better than solar or wind energy for rural areas of developing nations. One question I do have is if biogas is the same as wood gasification. I am not very familiar with biogas, but from what this article describes, it sounds different.

I would be curious to find out what kind of enzymes and bacteria are required to make biogas. It seems like it would be something fun to experiment with. I would like to see if I could make a biogas generator in my backyard.

ValleyFiah

I have a friend who goes to Middlebury College in Vermont. The university has a combined heat-and-power biomass energy plant that supplies over half of the energy for the campus.

From what I understand, the plant produces biogas from things like wood chips and willow. The gas is then burned to run a turbine, and the exhaust is pumped to heat the buildings in the university.

My friend told me that the University plans to produce all of its energy and then some from the biomass, even going so far as to grow the fuel on university grounds. It is interesting how innovation is beginning to take hold now that fossil fuels are not enough to power the world.

submariner

What an interesting article. After reading this article, I figured out what the eternal flame at the landfill a few miles from my house is. I never knew that you could use this gas for energy. Now I have to wonder why my dump is not making full use of this methane gas as an energy source to generate electricity. It would make perfect sense.

Post your comments
Login:
Forgot password?
Register:
    • Some farmers use biogas from pig manure to power their farms.
      By: Anatolii
      Some farmers use biogas from pig manure to power their farms.
    • Once purified, biogas can be injected directly into existing natural gas pipelines.
      By: Jim Parkin
      Once purified, biogas can be injected directly into existing natural gas pipelines.