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Given the fuel density problem it's interesting we haven't seen any hybrid designs that generate electricity with an ICE engine (like the range-extenders in som

Given the fuel density problem it's interesting we haven't seen any hybrid designs that generate electricity with an ICE engine (like the range-extenders in some PE cars like the Volt or the i3). I assume the added weight of the engine would cancel out some of the benefit.

rdl 9y ago
There are some (for the Octocopter from Workhorse) http://workhorse.com/surefly http://workhorse.com/surefly
greglindahl 9y ago
There are hybrid designs, and you can also do tricks like charging the batteries from running a prop backwards when descending... similar to regenerative braking in electric and hybrid cars. You'll note that hybrid cars aren't exactly winning in the market.
minitoar 9y ago
This is a good idea though, it gives you some flexibility in trading off range and payload. Probably maximum take off weight is the limiting factor here. But if it's just me, and I have 200 lbs of extra payload, why not load that up with 20 gallons of fuel and a tiny ~25hp generator.
Gibbon1 9y ago
I think Airbus and others are poking at hybrid turbo fan designs. One reason is that high bypass turbo fans are hitting limits due to fan diameter. If you use electric motors to drive the fans you can have multiple fans per engines. Like a 2:4 configuration, 2 turbines feeding 4 fans. Some advantages to this. 1. Much higher bypass ratios. Maybe close to double. 2. Ability to shift power around to keep the aircraft thrust balanced in case of an engine failure. If you have a battery then you also get. 3. Potentially much faster throttle response. The slow throttle response of turbine engines is a real issue that kills people. 4. Ability perhaps to take off and land with minimal turbine power. Which reduces noise. Thing is all this stuff has only recently gotten cheap enough and commercial aircraft probably take 10-15 years to develop and roll out.
phkahler 9y ago
There isn't much point to a hybrid gas/electric aircraft. Most of the value in cars is converting kinetic energy back to electricity when stopping. There's a bit from running the engine at peak efficiency as often as possible - if that produces an excess of energy you charge the battery for a while and then run in pure electric mode for a bit (engine off). But aircraft tend to run at high power all the time and don't stop much. Same thing with boats.

rdl 9y ago

There are some (for the Octocopter from Workhorse) http://workhorse.com/surefly http://workhorse.com/surefly

greglindahl 9y ago

There are hybrid designs, and you can also do tricks like charging the batteries from running a prop backwards when descending... similar to regenerative braking in electric and hybrid cars. You'll note that hybrid cars aren't exactly winning in the market.

minitoar 9y ago

This is a good idea though, it gives you some flexibility in trading off range and payload. Probably maximum take off weight is the limiting factor here. But if it's just me, and I have 200 lbs of extra payload, why not load that up with 20 gallons of fuel and a tiny ~25hp generator.

Gibbon1 9y ago

I think Airbus and others are poking at hybrid turbo fan designs. One reason is that high bypass turbo fans are hitting limits due to fan diameter. If you use electric motors to drive the fans you can have multiple fans per engines. Like a 2:4 configuration, 2 turbines feeding 4 fans. Some advantages to this. 1. Much higher bypass ratios. Maybe close to double. 2. Ability to shift power around to keep the aircraft thrust balanced in case of an engine failure. If you have a battery then you also get. 3. Potentially much faster throttle response. The slow throttle response of turbine engines is a real issue that kills people. 4. Ability perhaps to take off and land with minimal turbine power. Which reduces noise. Thing is all this stuff has only recently gotten cheap enough and commercial aircraft probably take 10-15 years to develop and roll out.

phkahler 9y ago

There isn't much point to a hybrid gas/electric aircraft. Most of the value in cars is converting kinetic energy back to electricity when stopping. There's a bit from running the engine at peak efficiency as often as possible - if that produces an excess of energy you charge the battery for a while and then run in pure electric mode for a bit (engine off). But aircraft tend to run at high power all the time and don't stop much. Same thing with boats.