Han wrote:

Apart from nuclear, there is water, wind, solar and more renewable
sources. Battery technology is now so far along that even tugboats
are equipped and are saving (in hybrid mode) 40-60% of their diesel
consumption. I'm not that sanguine about the "greenness" of
manufacturing high yield batteries, but that should also improve with
demand. For now, I think the only transportation that would be
difficult to replace is jet planes.

Batteries are not "fuel sources," they are "fuel storage devices." Just like
the gas tank on an automobile.

"Alternative energy sources" can do no more than nibble at the margins. All
those you mention make up less than 5% of our energy needs.

Of course if we poured billions upon billions into research and development,
we might be able to increase that to 10%.