Boeing states that using ethanol is currently not an option. Ethanol has only 60% of the energy content of Jet-A fuel, and would require medication to existing aircraft designs to include larger wings, larger engines, and a 35% heavier takeoff weight, all of which substantially lower performance and negate any benefits from using ethanol. Liquid hydrogen also poses design problems.

 

For now, it seems investments in synthesizing jet fuel are more inviting to the aviation industry, and Boeing recommends spending the bulk of efforts on converting the ground fleet while the air fleet works on synthesizing jet fuel.

 

Boeing is planning to roll out the new 787 this summer, which boasts a 20% increase in fuel efficiency through design improvements, which is a major improvement that has customers from around the globe buying up 787s.