Yann LeCun (Vice-President, Chief AI Scientist at Meta):

  AI datacenters will be built next to energy production sites that can produce 
  gigawatt-scale, low-cost, low-emission electricity continuously.

  Basically, next to nuclear power plants.

  The advantage is that there is no need for expensive and wasteful
  long-distance distribution infrastructure.

  Note: yes, solar and wind are nice and all, but they require lots of land
  and massive-scale energy storage systems for when there is too little sun
  and/or wind. Neither simple nor cheap.

Microsoft paying $100/MWh to restart Three Mile Island nuclear power plant:

https://news.ycombinator.com/item?id=41601443

This is so wrong it has to be misdirection. (a desperate attempt to change the issue to the one you would prefer to address).

Nuclear has never been cheap and never will be. How long the transmission lines will stretch across the prairie is meaningless.

Cooling costs is a much more..fruitful discussion question..., but that has nothing to do with where the electricity comes from.