Originally Posted by
tdracer
Unless there is a massive breakthrough in battery technology, battery powered aircraft will never be viable for other than short hops - simply too much mass in the needed batteries. Similarly, the difficulties with H2 storage mean it's unlikely to ever be viable for other than short range operations.
Various methods of creating carbon neutral synthetic kerosene (e.g. biofuels) hold far more long term promise (my personal favorite is using algae as a feedstock for biofuels - raising algae can use existing waste products and takes only a small fraction of the area that corn/soy/etc. based biofuels require). All this stuff with batteries and H2 for anything other than short range is mainly political posturing and/or investment cons.
A university in Germany has created "grey goo" - Hydrogen stored in a magnesium-based grey paste that can be pumped and stored like diesel. Simply add water and deliver the mix to a Solid Oxide Fuel Cell which turns the hydrogen into electricity and more water. That would be the best way to power cars, trucks and potentially aeroplanes subject to seeing how the fuel density works out for range and power etc.
Hydrogen can now be created at a cost comparable to diesel/petrol but I don't know how practical the magnesium paste is in cost or mass production terms.