This page gives a Sankey visualisation of Total Final Energy Consumption.
Final energy refers to the energy in useable form. This contrasts to useful energy, which is the fraction of energy that then actually gets used for its intended purposes. For example, petroleum is a final energy of form oil; powering a car is useful energy. When converting primary energy into final energy, there will often be efficiency losses. For example, not all petroleum will be converted into kinetic energy; some will be lost as heat or noise.
PTEC fixes the useful-to-primary conversion efficiencies at the current technology-sector specific value. This methodology is laid out in Way et al. (2020). PTEC Scenarios fix useful energy growth at 2% per annum and then works out accordingly how final energy consumption is needed to satisfy this. A more conversion efficient technology means that less final energy is demanded. Thus, shifting from less inefficient fossil fuels to more efficient renewables lowers TFC, whilst maintaining the level of useful energy.
Below you can compare the different PTEC and IEA scenarios.