What is the ultimate source of all energy on earth?
Primarily, the sun with a few exceptions.
Do a Socratic search for the related question that was answered earlier:
"What is the source of energy for nearly all life on Earth?"
Basically, the sun powers the biosphere, the hydrosphere, atmosphere, and makes life on Earth possible.
Heat energy from the Earth's core and mantel drive plate tectonics. This same heat energy is used by humans for geothermal energy.