The concept of ‘net zero by 2050’ has proved a powerful political and narrative focusing device. However, the concept requires careful translation to enable the detailed analysis required for the development of decarbonisation strategies for countries, sectors, cities and companies. In this paper, we unpack what ‘net zero’ and ‘net zero by 2050’ mean both at a global and sub-global level, and from there, develop an initial framework to guide the modelling of detailed net zero scenarios for the South African power sector.