A huge reserve of natural gas capable of generating 2,680 mega watt power annually for 30 years has been detected in Rajasthan's border district of Barmer. Seven block areas of Barmer has been found to possess coal-based methane reserve which could be gainfully exploited for the state's economic development, according to an official report made available in here. An estimated 30 per cent of the hidden natural resource could be made use of , it said.