Even if a "new energy cavalry" would exist (defying the current understanding of thermodynamics), the overhaul from the oil-based to a new infractructure would be just stupendous - how many engines and cars would have to be replaced, how many gas stations discarded? Who will the suffer costs of the overhaul? Gosh, do we have realistically enough aluminium (or whatever material) to run billions of cars? Maybe we would be just better off sucking oil still.

Besides, is it comfortable to be so dependent on a team of lucky inventors?

Praying for a technological breakthrough just in time is like expecting salvation from a higher power in the face of Rapture - the modern "rational" faith is no different from old Christian myths, after all.