Ok Tedi Mining Ltd generates its own electricity to supply the mine, its processing plant, and the local township of Tabubil. Two ‘run of river’ hydroelectric plants are backed up (or ‘firmed’) with diesel generator sets. The installed capacity of the two hydroelectric plants is 59 MW (57 MW at Ok Menga and 2 MW at Yuk Creek) firmed with 61 MW of thermal generator capacity. The Ok Tedi mine site is the longest running open-pit copper, gold and silver mine in Papua New Guinea.
The hydroelectric plant supplies about 80 percent of the electricity required by the mine, its plant and Tabubil. The power plant, over two decades old now, is an example of a mine site using intermittent renewable power with back up diesel generation. It demonstrates the key strengths and weaknesses of the use of intermittent renewable electricity generation. The intermittent renewable generation capacity decreases GHG emissions, and in this instance the hydroelectric power is low-cost energy. However, in the absence of energy storage, a system dominated by an intermittent renewable energy supply (such as OTML’s) requires either a connection to reliable grid power or investment in building and running hydrocarbon fuel fired firming capacity.