Gasoline is about 8 pounds per gallon, so your car has 120 pounds of gas when full. The LI battery in a Tesla is over 1000 pounds all the time. Other than that electric planes are a fantastic idea. I’m starting my own electric plane company. I will be CEO and make $1mm per year. I just need some investors. Please send money.
Diesel (jet fuel) is 6.8 lb/gal, but it contains significantly more energy per unit mass; the energy density of jet fuel, on a per-weight basis, is almost identical to that of avgas.
Otherwise, I agree with your sentiments, irony included.
Even the best currently available lithium-ion batteries only have about 3% the energy density of aviation fuel. Of course, electric motors are much more efficient than internal combustion engines. If we assume 33% thermodynamic efficiency of small piston aircraft engines (a high estimate, but do-able) compared to something better than 90% for electric motors, we can triple that 3% energy density estimate; that puts the net recoverable shaft-power energy density for lithium batteries at about 9% of that provided by hydrocarbon fuel.
So yeah. I think the people behind this aircraft investment are engaged wishful thinking, at least for the next decade or so.