Naysayers claim the flight was just a load of PR propaganda, that biofuels are impractical on a wide commercial scale due to the massive amounts of land that would be needed to produce the fuel. Virgin counters that the flight was meant to prove that alternative fuels could be used, and it acknowledges that the coconut-based concoction used on the flight isn’t what they’d use long term. For that, they’re looking towards algae.
Hmm. Seems like a decent idea on paper. But has anyone come close so far?