The Powerplant is the core energy source of a Mekton or other mecha.
In "whitebox" Mekton[]
In this edition, Powerplants were described as Tachyon Furnaces.
In first-edition Mekton[]
In this edition, Powerplants were described as Neutrino Furnaces.
In Mekton II[]
In this edition, Powerplants were described as Nucleonic Fusion powerplants.
In Mekton Z[]
In this edition, Powerplants were assumed to be nuclear fusion furnaces of some type (although fission reactors, free plasma, and matter-antimatter systems were also considered options) available in "Hot" and "Cool" varieties. Mekton Z+ offered special choices for Powerplants such as Power Cells, Combustion engines, and Bioenergy power sources.