ENG: electric propulsion in commercial aviation

The introduction to electric airplanes means a great challenge in commercial aviation


The biggest challenge is the low energy density of batteries. Jet fuel has an energy density of about 12,000 Wh/kg whereas commercially available lithium-ion batteries have an energy density at the cell level of about 250 Wh/kg. Energy density at the pack level, including the weight penalty for thermal-runaway containment and other safety features, is typically 20% lower.

Battery efficiency is improving at about 5-8% a year. NASA conservatively projects that batteries with 350-Wh/kg energy density at the pack level could be commercially ready by 2030 and would enable all-electric, short-range, 30-seat aircraft.