Agree. I think the big breakthrough is going to be with figuring out some sort of replacement for the li-ion battery in terms of eletrical powered aircraft. Batteries are just way too heavy for how much energy they hold. There has to be a better way. I think we need some out of the box thinking for this one.
I know solar energy is advancing, what about if we put thin-film solar cells on the exterior of the body of the aircraft? That might allow greater distance travel without much additional weight. There is already solar powered aircraft that traveled around the globe called the solar one. It is experimental but still a good concept to look at.
Put kerosene in a tank to drive a generator to provide electricity when taking off, and as backup to generate DC for charging batteries when necessary.
Now instead of kerosene burning in a jet engine, "we are all fucked if it doesnt work", its burning in a simple compact, "fuck it if it doesnt work", generator.
There are a few nice things about this. One is, it decouples your power generation from your thrust generation. If the generator fails, you still have a perfectly usable engine for some time. You can declare an emergency and land at the closest airport (easy to do if you are GA in the US). Same goes for all fuel starvation scenarios, fuel contamination, fuel pump malfunctions (for aircraft that use those).
If you are using a turbine as a generator, it can probably burn anything you'd classify as fuel.
Electric engines will probably get away with longer periods between overhauls and are more reliable.
This will not be cheap though. It also introduces a high voltage, high power electrical bus where there was none before. And it is a more complex approach, with more things to go wrong, even if it may save in maintenance. For instance, take your average Cessna: you can lose your entire plane electrical system and your engine won't care. It has (redundant) magnetos which are coupled to the engine itself and will spark as long as the engine is rotating. Fuel is gravity-fed for the most part. So as long as your have fuel in your tanks (and throttle and mixture controls are in the right positions) the engine will run. Some of your critical instruments (like the artificial horizon) are mechanically powered (vacuum pump) so you can still use them without electric power.
If you lose your electrical system in a hybrid (or electric plane), or if you have to turn it off (fire?), this is now a engine-out situation. You are also going to lose your instruments.
A turbofan engine is pretty much a turbine "generator" mated to a propeller. Turbine generators are preferred over piston-based generators where weight matters. Airplanes often have a separate turbine generator (called an APU) for on-board electricity.
I know solar energy is advancing, what about if we put thin-film solar cells on the exterior of the body of the aircraft? That might allow greater distance travel without much additional weight. There is already solar powered aircraft that traveled around the globe called the solar one. It is experimental but still a good concept to look at.