The Geological Survey of India (GSI) has estimated the total reserves of all grade coal in India with seams of above 0.5 m ofthickness(uptoadepth of 1200 m) as 247.84 billion tonnes. The estimated reserve of the coking coal is about 29.70 billion tonnes (non-coking coal reserve being 166.32 billion tonnes).
The proved reserve of the coal in the country is 92.96 billion tonnes (37.50%) which is expected to last for another 150 years at the present rate of consumption (400 million tonnes annually). The total lignite reserves are estimated at about 37.15 billion tonnes, bulk of which is found in Tamil 862 million tons (Table 16.11). Table 16.11 clearly exhibits that coal reserves are very unevenly distributed. About 85 per cent of the total proved coal reserves of the country are concentrated in only five states of Jharkhand (38.10%), Orissa (16.31%), Chhattisgarh-Madhya Pradesh (18.16%) and West Bengal (12.25%).
There is a real concentration within each state as well. For example Jharia coal field alone accounts for 39.45% of the total reserves of coal in Jharkhand, followed by Karanpura (19.26%) and Bokaro (14.65%). Three coal fields of Chhattisgarh-Madhya Pradesh (Singrauli 23.3%, Mand-Raigarh 23.11%, and Korba 22.17) contain over two-third (68.58%) of the states coal reserves.
Almost entire coal reserves of Orissa are concentrated in Talcher (53.94%) and lb river valley (46.06%). Over 90 per cent of the coal reserves of West Bengal are found in Raniganj coal-field. Raniganj is the largest coal field of the country with 11.1 percent of the total (9.66% of the proved reserves) coal reserves of the country. Godavari and Chanda- Wardha valleys account for most of the reserves in Andhra Pradesh and Maharashtra respectively.