It's not like the machines will ever be free, just the fuel. And it's not like the price of energy will go to zero, just be cheaper. To drive down the price of energy you first need to be taking a large slice of a trillion dollar pie.
replyIf fuel or any other form of energy becomes virtually limitless and free, any form of matter will eventually also be kinda limitless and free. Could take longer than humanity will ever last though.
replyIn the 'short' and current term there is still lots of money to be made in fuel indeed, but advancements in fossil free energy could make a real shift.