[...] Assuming these electric aircraft could be built, would they actually lower emissions? At present, no. Given the average emissions involved with powering the US grid, the emissions involved with powering an electric aircraft (including losses during transmission) would be about 20 percent higher than those generated by a modern, efficient jet engine. That doesn't mean they'd be entirely useless from a climate perspective, though. Once the additional warming effects of aircraft are taken into consideration, the electric aircraft comes out ahead by about 30 percent.
Future considerations complicate things pretty quickly, though. The price of renewable energy is expected to keep dropping, which will make renewables a larger part of the grid, lowering the emissions. The authors estimate that the vast majority of charging will take place during daylight hours—the peak of solar production—as well. Assuming future solar production leads to a discount on electric use during the day, it could help the economics of electric aircraft; currently, they only make sense economically with fuel at about $100/barrel.
How all of this would affect air travel is very sensitive to the capacity of future batteries. The authors estimate that an effective range of about 1,100 kilometers would allow electric aircraft to cover 15 percent of the total air miles (and corresponding fuel use) and nearly half the total flights. That would raise the total electricity demand by about one percent globally, although most of that would affect industrialized nations. Upping the range to 2,200 kilometers would allow 80 percent of the global flight total to be handled by electric aircraft.
Zeppelins still don't seem to figure into the answer.
(Score: 2, Interesting) by khallow on Saturday December 15 2018, @04:14PM
Most jets are turbines, let us note. Turbines can go a little into the supersonic regime. The key is to slow incoming supersonic air to subsonic speeds (expansion and heating) for the turbine to grip, and then eject at supersonic speed (reverse of the initial process). Certainly, they'd be able to function at the normal high subsonic speeds that passenger jets currently travel at.
The big problem is the battery mass.