Comment by qingcharles

17 hours ago

The energy density doesn't work for now. Everybody hoping for that breakthrough, and battery aircraft are moving into certain sectors (drone delivery, air taxis etc).

One of the trade offs is that engines are actually ridiculously heavy. Compact, extreme high power electric motors are starting to be commercialised. But also, fuel burns so you lose weight as you’re flying whereas batteries stay the same.

Electric aviation is interesting but as someone who knows a bit about the industry, biofuels make more sense here.

Structural batteries were supposed to be the solution where the density wasn't so important. I don't really have a good understanding of the ration of fuel weight to structural weight in existing aircraft though.

  • casing is around 25% of the mass of a cylindrical cell, with the rest being actual battery bits that can't have any stresses applied. is 25% weight saving that significant?

Jet engine and wing efficiency have increased enormously over the last 50 years.

  • With diminishing results.

    Turbofans and supercritical airfoils are done to the point of engine manufacturers looking to propfans and alternative materials (carbon fibre) to eke out further efficiencies.

    Although carbon fibre has significant down sides.