A major overhaul of the Third Powerplant, which contains generators numbered G19 through G24, began in and will be continuing for many years. Among the projects to be completed before the generators themselves can begin to be overhauled include replacing underground 500 kV oil-filled cables for G19, G20 and G21 generators with overhead transmission lines (started in ), new 236 MW transformers for G19 and G20 (started in ), and several other projects. Planning, design, procurement and site preparation for the 805 MW G22, G23 and G24 generator overhauls are scheduled to begin in 2011, with the overhauls themselves to start in 2013 with the G22 generator, then G23 starting in 2014, and finally G24 starting in 2016, with planned completions in 2014, 2016 and 2017, respectively. The generator overhauls for G19, G20 and G21 have not been scheduled as of 2010.
