Stay tuned, electrical generation could be the new cheap energy. Ballard Power Systems, a Canadian fuel cell manufacturer, is contracted with Volkswagen's fuel cell development program and a couple of large bus manufacturers with working prototypes in service, not to mention providing the power for Toyota's corporate offices in Torrance, CA. All kinds of science fiction stuff is happening right now and almost none of it was predicted or promised 40 years ago. About the only prediction that has been reasonable useful from the last 50 years has been Moore's Law. ("The complexity for minimum component costs has increased at a rate of roughly a factor of two per year. . .") Gordon Moore's succinct technology estimate has been reasonably accurate for at least 30 years and there is every likelihood that it will be revised upward with new technology.
POSTSCRIPT: I'm hiding in New Mexico from MN's 2017 and the Trump bullshit and hanging with a mechanic friend who has a huge collection of battery powered tools. If anything demonstrates the rapid evolution of batteries, it might be powered hand tools. He has a selection of batteries from the last 10 years of impact tools that range from old Makita's 14V, 10W nicads to the most recent 14V, 40W lithium-ion batteries. The weight and size change is mind-boggling. The whole tool weighs less than the old battery used to weigh, by a long shot. Even recent technology batteries seem primitive in comparison to the new stuff.