The National Thermal Power Corporation plans to add 20,000 mw of installed generation capacity by 2012. This was stated by Mr C.P. Jain, chairman and managing director of the corporation, while addressing the 'customers meet' for northern region, here today. He said the corporation was set to execute three projects at kahalgaon, north Karanpura and Barh in easterns region with a total capacity of 5,280 mw, to meet the demand for power in the northern and western regions of the country through low cost pit head generation.