Between the upper boundary set by the carrying capacity of the planet, and a lower boundary set by decent levels of wellbeing for all lies a band of sustainable energy use, situated somewhere between energy poverty and energy decadence. [...] However, there is no guarantee that the maximum levels are in fact higher than the minimum levels.
https://solar.lowtechmagazine.com/2018/01/how-much-energy-do-we-need.html