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.
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.
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.
