Current world energy consumption is 180,000TWh. Of that, 150,000TWh is from fossil fuels or biomass.
A 1 GW nuclear reactor produces 8.76TWh of electricity per year.
150,000 / 8.76 = 17,123 reactors required to replace fossil fuels. (there are currently 436 nuclear power reactors in the world)
If a new reactor were commissioned every day, it would take 47 years to replace the existing fossil fuel infrastructure.
The United States consumes about 27,000TWh of energy per year. Assuming a constant load, it’s 3TW. In 2022, the US installed 11GW of solar PV. At that rate, it would take 272 years to switch to 100% solar.
Jean-Marc Jancovici made some compelling presentations about our energy predicament, years ago. But they still hold up.