The Big Misconception About Clean Energy

The vast majority of what we use energy for doesn't really have to use energy.  If you go from one place to another, and back, your potential energy is the same at the end of the trip as it was before.  Going uphill necessarily costs energy, but going downhill gives it all back.  So a perfectly efficient car would use no energy over the course of a whole day's round-trip commute.  If the grocery store is uphill and home is downhill, a perfectly efficient electric car would put some energy back into the grid instead of charging.  Heating stuff up necessarily costs energy, but it gives that energy back when it cools down.  So a perfectly efficient high-temperature process would use no energy at steady state, as the product going out would provide all the heat to warm up the materials coming in.

Of course, perfect efficiency is impossible.  Practically, you do have to use some energy for all of these processes.  But real-world efficiencies are way below what they could be.  

The main point of the video is correct: we should not assume that dealing with climate change means deprivation for people around the world.  But the attention-grabber line is incorrect: we should not take for granted that efficiency improvements can't be made alongside the switch from fossil fuels to renewable sources of energy.  We need to switch to carbon-free energy, but whether efficiency improvements will outweigh growth isn't predetermined one way or the other.