Here is the percentage of U.S. energy derived from non-fossil fuels (nonFF), renewables, and nuclear power, for the last 4 decades. The trend looks somewhat encouraging:
But if you include fossil fuels, it looks much less encouraging -- in fact, I would call it positively discouraging:
What we need is to basically to switch the positions of the red and black curves. I could project them out and see where they cross, etc., but why bother -- it's clear that whatever we've been doing won't get us there for a couple of centuries.