Biomass as an energy source is limited by net primary productivity. Humans already appropriate a large portion of this (~20%), and total fossil fuel consumption would roughly double this (inexact numbers, it's been a while since I've looked at this).

Factoring in typical assumptions of population and economic growth, and the picture darkens further.

We simply don't have available biomass to power the present economy, let alone one with more people of net higher average wealth. There are reasons humans switched from renewable to nonrenewable energy resources. Unfortunately the practice is unsustainable on several fronts.

https://old.reddit.com/r/dredmorbius/comments/2cvap7/the_int...

http://www.eoearth.org/view/article/153031/

http://agroinnovations.com/blog/2007/04/27/the-photosyntheti...

https://web.archive.org/web/20120810132407/https://environme...

I especially recommend Jeff Dukes, "Burning Buried Sunshine" (2003):

https://dge.carnegiescience.edu/DGE/Dukes/Dukes_ClimChange1....

That’s what they want you to think, but there aren’t enough byproducts to satisfy energy demands.