It is an invalid discussion, and a waste of energy to talk about fixing the energy problem as some kind of "Cost". Fixing it blows away all concept of cost, because cost is a capital sum, whereas what is obtained by the fix is something accumulating forever, for all practical purposes. By the fix we obtain unlimited free energy, thus unlimited wealth, which outweighs anything we might define as cost.
Not fixing it, however does have a cost, an infiinite cost, the price is extinction.
The only way we will have that fix is to stop messing around with language and figures confusing the issue. By that we've wasted over 120 years (Since Nilola Tesla's free energy project was stopped, on account of "Cost"), and it has cost two world wars, and countless millions of lives.
Why keep spending lives, aren't they the most valuable thing of all?