Then we have to ask about alternatives. French TGV trains output about 10MW, and can carry over 600 passengers. Three of the solar arrays for these hypothetical green Hindenburgs would run one train, and you’re not stuck with shitty thin film panels. The trains will move twice as many people.

If we’re talking cargo trains, those max out around 3MW, so just one of these solar Hindenburgs. They will carry far, far more cargo.

Things like propeller efficiency also apply to airplanes.

So we’re still stuck where things were going when Hindenburg burned away. Other things were surpassing it, they also improved in the time since, and there isn’t much point beyond novelty.