I tried looking it up, but I can't do the math to get the answer.

According to Wikipedia,

(energies in joules)

1.5×1022J total energy from the Sun that strikes the face of the Earth each day

3.3×1031 J total energy output of the Sun each day

What percentage of solar energy does Earth receive, and what percentage is 'wasted' on ungrateful extraterrestrial lichen, or simply dissipates in the depths of deep space?

Orders of magnitude (energy) - Wikipedia, the free encyclopedia