Where will all of this energy come from? Where will future energy demand come from? For all that and more be sure to check out the International Energy Outlook 2016 from the United States Energy Information Administration.
The International Energy Outlook 2016 (IEO2016) Reference case projects significant growth in worldwide energy demand over the 28-year period from 2012 to 2040. Total world consumption of marketed energy expands from 549 quadrillion British thermal units (Btu) in 2012 to 629 quadrillion Btu in 2020 and to 815 quadrillion Btu in 2040—a 48% increase from 2012 to 2040
The report get into a lot from conventional and unconventional (like fracking) oil and gas, renewables, coal, nuclear, and a lot more.