> single human brain can often do in ~15Watts

There were similar arguments when AlphaGo showed up and beat master Go player Lee Sedol, but is power(in Watt) the right measurement? I always feel like it should be the total energy(in J or Cal) required to transform a computing device like biological brain or electrical computer from knowing nothing to being capable of a skill like Go game. In such sense, deep learning is still more energy efficient than human.