Creative Solution to the Energy Crisis
Picture yourself driving along the winding country roads in central Vermont, it is early fall, your windows are open and Joni Mitchell is gracing the airwaves with her soulful melodies. You are at one with the world, you take a deep breath, inhaling the crisp autumn air and then it hits you- the smell. At first it’s just a whiff, a hint of something sour. In no time you’re rolling up your window as full on nausea engulfs you. Twenty four hours a day, seven days a week, fifty two weeks a year there is one certainty: cow shit. The more tasteful term is manure, but for all of those in the world who live in areas with more bovine citizens than human ones, the smell merits no such enlightened vocabulary. Incredibly, some innovative minds have begun putting bad smells to good use. Cow power is a new undertaking of Central Vermont Public Service (CVPS) and has been gaining popularity as a way to create electricity and supplemental incomes for dairy farmers in Vermont. There are methane digestion initiatives similar to the one in Vermont being instituted all over the country. The adaptability of the methane digestion process makes methane digestion a viable option for producing electricity with low environmental impacts.
Methane digestion is not a new technology; it was first implemented in India in 1859 and has recently begun to gain popularity among farmers in the US due to rising energy costs but still remains a largely unknown energy source (Gardner 2006). The science behind creating electricity from cow manure takes advantage of the natural gasses which are produced by the digestion of manure by bacteria. First the manure is collected (usually by a mechanical floor scrapper and conveyor belt system). The manure is fed into the anaerobic digester. The digester is a closed concrete holding tank that usually has a 21 day capacity (CVPS 2006). The waste is held at 100 degrees Fahrenheit to allow the bacteria to digest the manure and release a combination of natural gasses, the main one being methane (ibid). As the pressure builds inside the digester the gas is fed into a modified natural gas motor. The motor turns an electrical generator which produces both electricity and heat (ibid). Much of the electricity produced is used immediately by the farm and any excess is fed back to the grid. The heat generated by the motor is also put to use maintaining the elevated temperature in the digester (ibid).. The byproducts of this operation are separated and the solids allowed to dry. The solid wastes are, surprisingly, odorless and can be used as bedding for the herd or sold to other farms for the same purpose. The liquid byproducts can be spread on fields as fertilizer and reduce the need for imported petroleum-based fertilizers (ibid).
Cow Power, is the name CVPS has given to the digestion of methane, generated by anaerobic digestion of cow manure to produce electricity. Ironically,...