In my opinion ,the best primary energy(+ secondary)is the heat of global warming.
Why ?
Because this energy is aviable throughout the world:
1°) 24H/day
2°)365 days a year
3°)all wheater operationnal includ polar temperature
This energy is free , directly exploited,and Zéro émission.

Heat is form of energy used by thermal engine.
To extract this heat from atmosphere is very easy,sufficient
to cool atmospheric air.