When there is true economic hardship, and oil reserves are ACTUALLY depleted, not ARTIFICIALLY, as they are now with regulations that hamper or prevent drilling in many locations, the market conditions will drive people to come up with a viable alternative energy.
God knows we haven't found it yet. Maybe it doesn't exist.(one that is both useful AND economically feasible)
Meanwhile, LET'S OPEN THE STOPS TO DRILLING AND REFINING, BABY!