Being able to harness a millionth of the Sun’s energy would be >10,000 times more energy than all of human civilization uses today
ELON MUSK: “Our progress toward a Kardashev Type II civilization, let’s have an aspiration that if we say that our goal is to get even a millionth of the Sun’s energy, that would be more than 1,000 times as much energy as could possibly be produced on Earth. About half a billionth of the Sun’s energy reaches Earth, so you would have to go up three orders of magnitude from that just to get to a millionth. We are very, very, very far from even having a billionth of the Sun’s energy harnessed in any way. So a reasonable goal would be to try to get to a millionth.”