Not just "an inefficient way". In the best case, biofuels are 2 orders of magnitude less efficient than solar. That said we could theoretically produce around our current energy needs with a perfect biofuel. (Existing biofuels are much, much worse than this theoretical fuel.) We'd just need to convert all land we currently use for agriculture to that purpose. (And then what would we eat?)

If his numbers are correct - and I see no reason to doubt it - biofuels have to be a dead end.