POSCO is supplying most fuels through the gases such as COG(Coke Oven Gas), BFG(Blast Furnace Gas), LDG(Linz-Donawitz Converter Gas), FOG(Finex Off Gas), etc. emitted from the process, and the surplus gases has to be used for private power station in steel works. In 2006, 79% out of electricity used at the head office, Pohang Works, and Gwangyang Works has been supplied itself for private power station by using by-product gas, recovery facility of energy such as CDQ and TRT, and LNG complex facility. In addition, the rest of 21% electric power has supplemented form outside.

From 2004 to 2008, POSCO is performing the '2nd Voluntary Agreement on Energy Reduction' with s goal of 1040000 TOE reduction which represents 6.9% of the amount of energy used in 2003. For such purpose, the total of KRW 890 billion will be invested in energy facility. Prior to this, POSCO has achieved over the goal by reducing 1260000 TOE, compared to 9.4% of the amount of energy used in 1997, in the period of the 1st Voluntary Agreement from 1999 to 2003.