You want someone to put "3.4*10^27 / 2^64" into a calculator? 200 million joules, using all the same assumptions. 50kWh. Though that leaves the question of how the energy requirements change when we're not going for extreme density (half a nanogram??).

If we instead consider a million 18TB hard drives, and estimate they each need 8 watts for 20 hours to fill up, 2^64 bytes take 160MWh to write on modern hardware. And they'll weigh 700 tons.

Edit: The quote is inconsistent about whether it wants to talk about bytes or blocks, so add or subtract a factor of about a thousand depending on what you want.