Renewable technologies are gathering speed, putting the world within reach of falling greenhouse gas emissions. Climate experts say they "struggle to wrap their heads around" the sheer size, scale and speed of the current transition.
The sun is the biggest source of Energy on Earth. There's no point trying to find an alternative energy source, because even if it existed, it would probably be much more expensive than getting energy directly from the sun.
and since all energy comes from the sun anyways, accessing it in the most direct way possible is obviously both most efficient and also least complicated. and that is why we have photoelectric machines, aka. PV panels.
Whatever is quickest, cheapest, and most effective for the area. Which will be nuclear in some cases, geothermal in others, hydropower in others...we need to do whatever works best and not shoehorn ourselves into (or out of) any particular zero carbon source.