Comment Re:a bright future (Score 1) 40
Some of the (often excitingly dreadful) stuff used by the orbital-launch rocketry guys might beat hydrocarbons on pure energy density; but I suspect that civil aviation may not be ready for hydrazine spills on busy runways and range safety officers blowing up the occasional airliner.
The exciting thing about solar aircraft(aside from it being cool that they are possible) is that, if you can get efficiency high enough, they are basically your only option for long-to-indefinite loiter. In-air refuelling costs a small fortune, so hydrocarbons are mostly out; and nuclear, the only other long-lasting fuel source; has been explored; but you don't name a project after the god of the underworld because it satisfies more conservative risk analysis.
The exciting thing about solar aircraft(aside from it being cool that they are possible) is that, if you can get efficiency high enough, they are basically your only option for long-to-indefinite loiter. In-air refuelling costs a small fortune, so hydrocarbons are mostly out; and nuclear, the only other long-lasting fuel source; has been explored; but you don't name a project after the god of the underworld because it satisfies more conservative risk analysis.