Mt Piper was originally built in the 1980s, then stored in near fully assembled state, before being commissioned in 1992 and 1993 (Units 2 and 1 respectively). While initially constructed as 660MW machines, both were upgraded to 700MW in 2009, with Unit one upgraded in 2023 to 730MW, using modern turbine technology, bringing the station total to 1430MW. Importantly, the minimum generation of these units has also been lowered to facilitate the modern requirements of lower minimum generation rates to better match the shape of renewables.