Electric Battery Passenger Airplanes (how soon?)
 

So I posted in 2006 http://www.pprune.org/spectators-bal...-feasable.html and in 2007 thread http://www.pprune.org/jet-blast/2620...-aircraft.html

What is the status for electric passenger airplanes?


If the kerosene jet engine airplane does 20 hour 900km/h range carrying 300 people.

why can't:

battery electric engine do 1 hour at 600km/h carrying 100 people?

What is the power/range/weight ratio difference between a kerosene jet engine airplane and a potential electric battery propeller airplane (no electric jet engine?)

If kerosene is 20 times more powerful per weight/size compared to battery electric engine, then why can't we "simply" use battery electric engine powered airplanes for all short ranges? Until battery capacity improves, recharge cycles increased and range can evt be extended.

The batteries can be charged from clean energy using wind, solar, thermal and even nuclear.

I would suggest this years B787 battery issues are relevant to your ideas.

An aircraft which can only fly for an hour is about as much use as a chocolate teapot. That is less than the block time of most short haul flights and doesn't allow any reserve.

Never
 

The energy density of gasoline is around 46 megaJoule per kilo according to this reference. Energy density - Wikipedia, the free encyclopedia
For Lithium ion batteries energy density is around 0.8 megaJoule per kilo. That implies, in a perfect world a range of (at best) 2% of what can be achieved from kerosene.

That's ignoring all the other show stopping objections, like could they ever be made acceptably safe, and the fact that no weight would be lost in travelling so aircraft would have to land at maximum take off weight with all that implies. Also the cost of the batteries would be vast, and there isn't enough lithium for such applications anyway.

If you are going to think the unthinkable, it might be better to ask what would we have to do if we were no longer able to fly at all, at any cost? By all means ask that question but as this is an aviation forum you might do better raising it elsewhere. :hmm:

What is the minimum range needed for reserve etc? Can this minimum be achieved by batteries and electric engine (maybe propeller) instead of kerosene and jet engine?

What is the maximum range of kerosene jet engine airplanes?

What is the ratio difference for weight/performance/range when using batteries and electric engine instead of kerosene and jet engine?

Even if batteries are 5x or 10x less efficient than kerosene, can it still be useful for short range flights, that's been my question for 5-6 years. Even when I tried asking Betrand Piccard he didn't really reply, maybe he doesn't know.

Wow, are you saying batteries and the electric engine is 50x less efficient per weight for range compared to the kerosene jet engine configuration?

Why are battery electric cars possible to replace gasoline powered cars if the batteries and electric engine is 50x less efficient per weight for range?

I understand kerosene is more efficient than gasoline, but is it that much more efficient?

What is the minimum range needed for reserve etc? Can this minimum be achieved by batteries and electric engine (maybe propeller) instead of kerosene and jet engine?

What is the maximum range of kerosene jet engine airplanes?

What is the ratio difference for weight/performance/range when using batteries and electric engine instead of kerosene and jet engine?

Even if batteries are 10x less efficient than kerosene, can it still be useful for short range flights (maybe with half the amount of passengers), that's been my question for 5-6 years. Even when I tried asking Betrand Piccard (search Charbax Bertrand Piccard on Google) he didn't really reply, maybe he doesn't know.

Jetsons anyone?

Would the solution be to transform the electric energy to hydrogen, store that compressed hydrogen on the airplane at 123MJ/kg, run the airplane from that safely instead of the kerosene jet engine?

I don't seem to be able to post links here. Searching for electric airplanes I found an interesting Cri Cri video on YouTube and Volta Volare GT4 4-passenger hybrid airplane they say has 300 mile battery range + 1000 mile gas powered:

There's PC-Aero's single seat Elektra One.

And an article about the Ce-Liner for 2030:

EADS VoltAir 2 years ago on NBC News website.

Electric motors are 90% efficient, compared to combustions 25% (or jet's even lower efficiency), so as you can see one can't just compare energy density between batteries and fuel. Battery power never needs to become as energy dense as gasoline - only 1/4 of that - to compete. If you add the much higher power-to-weight ratio of electric motors (about 10hp/kg - blows away anything else, even jets) the gap closes even more.

But ultimately, what will make the revolution in electric propulsion is price. Oil can't be produced in your backyard, so they have you over a barrel (pun intended). The very definition of a captive audience. They'll squeeze you dry, and governments will tax it until the last drop, so sooner or later the cost benefits of electric will become irresistible, even to the point where you might accept a slightly lower speed/range/whatever. Electric can be produced in your backyard and they can't control it in the way the do with oil.

My predictions I still stand by - in 20 years time there will be very little gas powered cars sold. Electric will be the prime mover for almost all transportation in the future, for sure. Like Elon Musk said - "With the one exception of rockets - they will be fossil fuelled still". I agree.

Awesome, I'd like to know what Airbus and Boeing are doing about electric passenger airplanes. How it may look like. How soon we may have something, perhaps based on how large a priority it may have.

I won't pursue this further beyond noting that even this would imply a tenfold improvement in energy density for batteries. If all the other (in my opinion insuperable) problems were overcome, this would give a 777 a maximum range of 2000 miles at most. Even that supposes that the efficiency of an electric motor remains at 90% by the time you have driven a propellor with it. So no transatlantic aviation would be possible.

Chip Yates says he wants to do a transatlantic flight next year with his electric airplane Long-ESA, swaping batteries 5 times over the atlantic ocean by docking to flying drones. How about that for extending range?

Can it somehow be made safe for a passenger airplane to dock with flying battery swap stations every 2 hours?

Maybe you'd have a hybrid so just in case the dock does not work (and there could perhaps be 2 or 3 backup drones nearby along the way), you can still switch over and have enough kerosene to reach any number of backup plans, getting to the next battery swaping drone area (perhaps if initial difficulty is a storm or something like that) or at worst having enough fuel to land even when doing a transatlantic flight.

How would the battery drones get up there? I dunno, maybe hot air balloons launched from boats along the way? Maybe the depleted battery can also get recharged by solar energy right up there in the air, not needing to be flown down and up from the boat each time.

<<Can it somehow be made safe for a passenger airplane to dock with flying battery swap stations every 2 hours?>>

Can you begin to imagine the problems this would cause? Airspace is clogged enough without having masses of "battery drones" hurtling around. It's just too ridiculous for words.

The ideas come across as having an edge of desperation.

On the off-chance you aren't actually a troll, have you even started to consider the energy consumption of drones that would need to be powerful enough to carry battery packs (heavy) at a similar speed to the cruising speed of the airliner?
That's got to cut into efficiency a little.

The idea of using compressed (even liquid) hydrogen as a fuel source has more merit. Not without difficulties, though. It's expensive to produce, and containment of same requires more dense materials than a typical container for kerosine. Nice, clean burning fuel source. But takes a lot of energy - along with the pollution that would entail - to make it.

Can't we just have lots of really long extension leads...can't see that being an issue... :}

OB

I'm imagining very big hot air balloons can maybe lift up the batteries, the batteries would actually be on an unmanned drone that can fly fast to follow the passenger airplane to dock to it, when the battery is swapped, that drone would fly back with the depleted battery to attach itself to that balloon again. The very big baloo system would also carry solar panels to charge the battery again and to keep the balloon battery drone system up indefinetely (creating more hot air as needed and doing all the automatic controls and getting commands for when to unleash the battery pack unmanned airplane from ground).

My guess is the battery pack and docking drone systems with solar panels would be so heavy it requires maybe a too large a balloon to keep in the air indefinitely and docking with an unmanned drone is maybe not that easy. May not be very practical for the passenger airplane to slow down every 2 hours to do maneuvers to dock with the drone to swap the battery.

Before I read the story earlier today on about Chip Yates Long-ESA transatlantic electric flight planned for 2014, I never considered that docked battery swapping for electric airplanes was a possibility.

I'm a big fan of Project Better Place for electric cars, which standard is all about all electric cars needing to have swappable batteries so the electric car battery range is not a problem, and also so people who buy electric cars don't need to buy the battery but instead lease/rent it from the renewable electric energy supplier who also owns all the batteries and ads newer better batteries to the system as those become available.

What's an "airplane"?