Energy supply solutions summary
Things that actually stand a chance to replace all fossil fuel energy in the near future:
- Solar panels: Only if they can be made cheaply without scarce minerals (it's ok if the efficiency is lower). Need to mass-produce enough to cover every rooftop. Need energy storage: sodium-ion batteries or similar. For homes/buildings
(...)( connected together via the power grid for some load balancing ) , rooftop solar would provide enough "general-purpose" electricity, but not always enough for heating. - Wind power: Mostly to generate hydrogen gas (which would be used as fuel instead of natural gas). Otherwise too intermittent, too far away for power lines.
- Nuclear: Only if it's thorium. Fusion is a pipe dream
(...)( although it's ultimately the best choice in the distant future ) , uranium-235 is too scarce, and uranium-238 reactors have too many weapons proliferation concerns.
Other renewables (geothermal electricity, hydroelectricity including tidal, and biomass waste) are limited to only a small percent of the world's energy.
There would be battery electric vehicles
In any case, it all becomes a lot easier if we drive less (some careers are an exception obviously) and buy less new stuff. Those factors alone account for 2/3 of the world's energy consumption.