For short, frequent hops, it could be practical depending the operating costs. The energy density of current battery tech is rough for aviation, but at least they’re trying.
One of the benefits of jet fuel based planes is that they get lighter as the journey continues as they exhaust their fuel, thereby increasing range. Obviously the weight of batteries never does so the current approach of battery powered electric flight will always have this burden with the only mitigation of developing batteries that weigh less.
I’m wondering if they solve for the high performance electric engines, they could pivot into liquid based fuel cells to provide the electricity. Direct Methanol Fuel Cell (DMFC) technology is well known today and not exotic. Methanol is one of the easiest hydrocarbons that can be created with electricity. Methanol is also energy-dense enough to be used as a good fuel too considering the space constraints on an aircraft. Using Methanol as a consumable would mean the jet would get lighter as it few just like jet fuel benefits.
My guess is the current barrier to this is the electrical yield of today’s DMFCs isn’t high enough to produce the power (energy in a moment) the electric jet engines would require. However, this means its another avenue for research that could make electric jets viable.
Could you parachute spent batteries over designated areas for collection and reuse to extend range?
(probably minimally, and any gains would be offset the weight of the battery release mechanism)
Hydrogen is pretty horrible as a portable fuel. Its density is extremely low even in liquid form as it only has 2.4 kWh per US gallon (~8.5 MJ/L) of energy compared to a gallon of gasoline at about 33.6 kWh (130 MJ). Methanol is ~17kWh for that same gallon and is liquid at room temperature. That liquid form of hydrogen also requires extremely high pressures and cryogenic storage which means heavier containment. You also then have to contend with boil-off. The hydrogen molecule is so very small it can leak through fittings and valves. Lastly, hydrogen on flame is almost invisible in daylight.
If this were a stationary application where weight and space considerations don’t matter, hydrogen could be a better choice.
For short, frequent hops, it could be practical depending the operating costs. The energy density of current battery tech is rough for aviation, but at least they’re trying.
One of the benefits of jet fuel based planes is that they get lighter as the journey continues as they exhaust their fuel, thereby increasing range. Obviously the weight of batteries never does so the current approach of battery powered electric flight will always have this burden with the only mitigation of developing batteries that weigh less.
I’m wondering if they solve for the high performance electric engines, they could pivot into liquid based fuel cells to provide the electricity. Direct Methanol Fuel Cell (DMFC) technology is well known today and not exotic. Methanol is one of the easiest hydrocarbons that can be created with electricity. Methanol is also energy-dense enough to be used as a good fuel too considering the space constraints on an aircraft. Using Methanol as a consumable would mean the jet would get lighter as it few just like jet fuel benefits.
My guess is the current barrier to this is the electrical yield of today’s DMFCs isn’t high enough to produce the power (energy in a moment) the electric jet engines would require. However, this means its another avenue for research that could make electric jets viable.
Which raises an interesting point:
Could you parachute spent batteries over designated areas for collection and reuse to extend range? (probably minimally, and any gains would be offset the weight of the battery release mechanism)
Still very fair point re hydrogen
Wouldn’t hydrogen cells provide a solution? Very small hydrogen powered engines output colossal power proportionally to their size and weight.
Hydrogen is pretty horrible as a portable fuel. Its density is extremely low even in liquid form as it only has 2.4 kWh per US gallon (~8.5 MJ/L) of energy compared to a gallon of gasoline at about 33.6 kWh (130 MJ). Methanol is ~17kWh for that same gallon and is liquid at room temperature. That liquid form of hydrogen also requires extremely high pressures and cryogenic storage which means heavier containment. You also then have to contend with boil-off. The hydrogen molecule is so very small it can leak through fittings and valves. Lastly, hydrogen on flame is almost invisible in daylight.
If this were a stationary application where weight and space considerations don’t matter, hydrogen could be a better choice.
Hydrogen is cool but comes with significant issues. It leaks, it’s extremely reactive, it’s hard to store and transport, etc.
Well, liquid hydrogen is, anyway
Let’s try to avoid repeating the Hindenberg.
“What part of ‘non-flammable helium’ do you not understand?!”
Now I’m picturing small electric aircraft for smaller groups of people, similar to the prop planes Indiana Jones took in those movies.