Despite their popularity, steam-powered cars had a very short life. Why? Because they needed up to 30 minutes to start. They were rapidly replaced by automobiles with internal combustion engines and electric starters. Automobilists abandoned their beloved steam cars because they wanted efficiency. The shift toward electric cars we are experiencing in the first decades of the 21st century is motivated by their higher energy efficiency compared to conventional cars—60 percent versus 20 percent. The pattern is the same: it is all about efficiency. Efficiency is a key driver of innovation.
