How Long Before Half of Global Energy Comes from Non-Fossil Fuels?

Daniel Yergin thinks it will take about 40 years to half-wean the world off fossil fuels. Vinod Khosla thinks it will take only 25 years for a global half-wean. Khosla is very optimistic about the future of biomass to liquids (BTL).

Up until the past year or two -- with the explosion of shale gas discoveries world-wide -- Al Fin energy consultants would have been closer to Mr. Khosla's estimate. But as the technologies of CTL and GTL begin to utilise nuclear process heat as an energy source, it grows more likely that synthetic fuels from natural gas, coal, and a combination of gas & coal will give fossil fuels liquids a big multi-decadal boost, beginning in the 2020s.

WSJ

MS. STRASSEL: How many years do you think it will be before half of our global energy production comes from non-fossil fuels?

MR. YERGIN: World energy probably is going to grow by 25% or as much as 35% over the next 20 years. I think the shift in the composition won't be too significant until after 2030, so maybe by 2050.

MR. KHOSLA: I guess 25 years. I'm definitely more optimistic.

...MS. STRASSEL: Vinod, in the past, you've talked about black-swan technologies—the idea of some innovative idea coming out and turning everything on its head.

MR. KHOSLA: Shale gas was a black swan. And my point is black-swan technologies will show up again. Shale gas was some combination of fracking, which we already knew how to do, and horizontal drilling that changed the assumptions around natural gas from "we need to import $100 billion worth" to "we can export it." The same thing will happen if an oil equivalent can be produced in country at $60 to $70 a barrel.

As soon as liquid-fuel technologies from things like wood chips, which are scalable, start to reach that level, our assumptions will change. _WSJ