Electricity from underground coal fires

Coal drives Indian economy. Coal mining started in 1774 with total production of about 6 million tones per year. The current production is greater than 286 million tones. Raniganj coal field is the largest coal mines in India. Like any other coal mines in the world, coal fire in Raniganj is very common. This is true with  other coal mines in the country as well.  For example, several coal seams in Jharkhand and Bihar are burning underground. Coal mine fires are due to primary combustion when oxygen and water are introduced through cracks and unsealed shafts. These coal fires continue through several years  Most underground coal fires exhibit smoldering combustion and may only involve relatively small amounts of coal capable of burning in the presence of small amount (2%) of oxygen.  To give an example of the magnitude of this hazard, in USA there are nearly 600 coal mine fires burning over a period of 80 years. Other under ground coal mines that are burning is located in Russia and in several east European countries.  These fires are located at shallow depth and the depth in many cased do not go beyond 400-500 m.  Till now this heat energy available is not put to use. Heat exchanger technology commonly used in geothermal power generation can easily be adopted in regions where under ground coal mine fire is common and perennial.  Continuous heat source from burning coal seams underground will provide continuous electric supply. This method controls underground coal fires, controls CO2 emission and generate electric power to million rural homes. We have the know how and need will to implement it!!