No they aren't "efficient". An internal combustion engine is, at best, 25% efficient. It's just been a cheaper fuel. Google it.
 Yes there is a "footprint" to manufacture PV and EV's, but the pollution they remove, far exceeds the one one required to create them. Google that too.
 Renewables won't replace petroleum. It'll be needed for manufacturing for a long time to come.
But renewables are quickly overtaking fossil fuels cost wise.
 Go to youtube and watch Tony Seba's presentation on the "Clean Disruption of Energy and Transportation.