Electric Motorglider Flies

ELECTRAFLYER FLIES TRIKE, MOTORGLIDER ON BATTERY POWER
(http://www.avweb.com/eletter/archive...ll.html#197632)
For the sport flyer who enjoys local fun flights and $100
hamburgers, Electraflyer's new battery-powered airplane may be
just right -- and with no fuel to burn, it can cut the cost of
that hamburger down to about 60 cents. That's how much it costs
to fully charge the lithium-polymer battery pack, says Randall
Fishman, president of the Electraflyer Corp.
(http://www.electraflyer.com/) The electric engine is mounted on
an old Monnet motorglider that Fishman built from a kit, and the
aircraft just this week earned its experimental airworthiness
certificate....


Watch the video:
http://www.youtube.com/watch?v=o_GCAy40RiE


Other electric aircraft:

http://www.youtube.com/watch?v=P8Pb_psj1A8
Sonex Electric Powered Flight, EAA AirVenture Oshkosh 2007
John Monnett



http://www.youtube.com/watch?v=WcWSI03NKo0
Eric Raymond with his Sunseeker electric powered self launching
sailplane discusses the engineering aspects of electric aircraft.


http://www.youtube.com/watch?v=RL18Oh_qSRM
Boeing's hydrogen fuel cell powered Dimona (a.k.a. Katana)
motor-glider is the first to fly in aviation history.
http://www.youtube.com/watch?v=XzeCQblYHic

* * *just right -- and with no fuel to burn, it can cut the cost of
* * *that hamburger down to about 60 cents. That's how much it costs
* * *to fully charge the lithium-polymer battery pack, says Randall

Yeah, plus the cost for a new battery after probably less than 1,000
recharges. Plus motor cost. Plus plus plus... And your hamburger will
ge cold when you arrive - if not even the restaurant has closed since
you flew that slow.

Take a small piston engine instead and get better performance at
similar or even lower total cost.

virtuPIC
--
Airspace V - international hangar flying!
http://www.airspace-v.com

On Mon, 14 Apr 2008 04:36:17 -0700 (PDT), virtuPIC
wrote in
:

* * *just right -- and with no fuel to burn, it can cut the cost of
* * *that hamburger down to about 60 cents. That's how much it costs
* * *to fully charge the lithium-polymer battery pack, says Randall

Yeah, plus the cost for a new battery after probably less than 1,000
recharges. Plus motor cost. Plus plus plus... And your hamburger will
ge cold when you arrive - if not even the restaurant has closed since
you flew that slow.


All valid points.

But the significance of this successful electrically powered aircraft
is that it (along with the very few others) clearly demonstrates that
electrically powered aircraft are somewhat feasible. For unlike
surface vehicles that only require power to propel them forward,
aircraft require additional power to sustain them in the air. So
successful electrically powered aircraft are significantly more
remarkable than electric cars.

The Li-ion batteries currently available on the market, while a
significant enabling technologic advancement over lead-acid batteries,
are not designed for the heavy demands of motive service. Given the
torrent of Li-ion cell advancements being announced regularly, I
foresee them becoming ever better suited to that service as time goes
on.

Take a small piston engine instead and get better performance at
similar or even lower total cost.

I'll bet the Model T owner said something similar about the Wright
Flyer. :-)

Larry Dighera wrote:

Other electric aircraft:

http://www.youtube.com/watch?v=P8Pb_psj1A8
Sonex Electric Powered Flight, EAA AirVenture Oshkosh 2007
John Monnett

http://www.youtube.com/watch?v=WcWSI03NKo0
Eric Raymond with his Sunseeker electric powered self launching
sailplane discusses the engineering aspects of electric aircraft.

http://www.youtube.com/watch?v=RL18Oh_qSRM
Boeing's hydrogen fuel cell powered Dimona (a.k.a. Katana)
motor-glider is the first to fly in aviation history.
http://www.youtube.com/watch?v=XzeCQblYHic

http://www.lange-flugzeugbau.com/htm...tares_20E.html


--
Message posted via http://www.aviationkb.com

"Kloudy via AviationKB.com" wrote ...
Larry Dighera wrote:

Other electric aircraft:

http://www.youtube.com/watch?v=P8Pb_psj1A8
Sonex Electric Powered Flight, EAA AirVenture Oshkosh 2007
John Monnett

http://www.youtube.com/watch?v=WcWSI03NKo0
Eric Raymond with his Sunseeker electric powered self launching
sailplane discusses the engineering aspects of electric aircraft.

http://www.youtube.com/watch?v=RL18Oh_qSRM
Boeing's hydrogen fuel cell powered Dimona (a.k.a. Katana)
motor-glider is the first to fly in aviation history.


http://www.lange-flugzeugbau.com/htm...tares_20E.html


You guys are all chasing yesterday's news. I think our own (happily wacky)
Jay M is right now redesigning his Tron outfit with more batteries and
retractable e-drive prop.

Then he'll be smirking all the way to the bank, thinking whether to go
single engine D-jet or twin engine Eclipse.

http://www.youtube.com/watch?v=RsF2RUMmpqc

(Remember, he who laughs last,...)

On Apr 14, 10:11 am, Larry Dighera wrote:
On Mon, 14 Apr 2008 04:36:17 -0700 (PDT), virtuPIC
wrote in
:

just right -- and with no fuel to burn, it can cut the cost of
that hamburger down to about 60 cents. That's how much it costs
to fully charge the lithium-polymer battery pack, says Randall

Yeah, plus the cost for a new battery after probably less than 1,000
recharges. Plus motor cost. Plus plus plus... And your hamburger will
ge cold when you arrive - if not even the restaurant has closed since
you flew that slow.

All valid points.

But the significance of this successful electrically powered aircraft
is that it (along with the very few others) clearly demonstrates that
electrically powered aircraft are somewhat feasible. For unlike
surface vehicles that only require power to propel them forward,
aircraft require additional power to sustain them in the air. So
successful electrically powered aircraft are significantly more
remarkable than electric cars.

The Li-ion batteries currently available on the market, while a
significant enabling technologic advancement over lead-acid batteries,
are not designed for the heavy demands of motive service. Given the
torrent of Li-ion cell advancements being announced regularly, I
foresee them becoming ever better suited to that service as time goes
on.

Take a small piston engine instead and get better performance at
similar or even lower total cost.

I'll bet the Model T owner said something similar about the Wright
Flyer. :-)

Boeing also recently flew a fuel cell + battery powered airplane.
http://www.avweb.com/avwebflash/news..._197531-1.html

This is a necessary step if GA is to survive past this century. The
technology is just getting started so things can only get better. With
piston engines, the good days are behind us.

On Mon, 14 Apr 2008 12:47:38 -0700 (PDT), Andrew Sarangan
wrote in
:


Boeing also recently flew a fuel cell + battery powered airplane.
http://www.avweb.com/avwebflash/news..._197531-1.html

This is a necessary step if GA is to survive past this century. The
technology is just getting started so things can only get better. With
piston engines, the good days are behind us.

Agreed.

With the ever increasing torrent of discoveries being made in physics,
I fully expect advancements in anti-gravity (not to mention quantum
computing) to occur before the end of the century. But I'm an
optimist. Just as likely, some fool will unleash the nuclear dogs of
war, and sterilize our planet.

That said, electrical propulsion does have the potential for three to
four times the efficiency (~90%) of internal combustion engines (~20%
to 30%). Unlike petroleum, sunlight is (for all practical purposes)
not a finite resource, and no nation or region has a monopoly on it.
Imagine a solar powered photovoltaic system on the ground that quietly
electrolyzes water into its constituent parts, hydrogen and oxygen,
percolating away all day long generating the fuel to run a fuel-cell
electric generator (with its exhaust consisting of only pure water).
Photo-cell technology (Spectralab) is currently approaching 40%
efficiency, and electric motors and controllers are =90% efficient,
so clean and quiet electric propulsion is clearly the future.

The application of electric propulsion for aviation today is in its
infancy, and only possible at all because of the technical
breakthrough provided by light Li-ion batteries enabling it. I look
for Li-Ion technology to steadily improve over time. As it is, the
individual cells used today are only approximately the size of common
AA batteries. Imagine the weight savings possible if larger cells
were produced; there would be significantly less steel jacketing
necessary. That said, it's difficult to imagine a battery with the
energy/power density of gasoline, so there will certainly be
tradeoffs.

Despite the fact that electric motors must use iron/steel in their
construction, they are significantly lighter (50%) than their
internal combustion counterparts. But when the wiring, controls,
batteries and perhaps fuel-cells are considered, I would guess the
weight of an electrically powered aircraft would be roughly comparable
to one powered by an internal combustion engine. So, with
significantly less power/energy density than gasoline, batteries will
not provide the same range/duration until they are improved further.
But it is encouraging to see progress being made at last.

Larry Dighera wrote:
On Mon, 14 Apr 2008 12:47:38 -0700 (PDT), Andrew Sarangan
wrote in
:


Boeing also recently flew a fuel cell + battery powered airplane.
http://www.avweb.com/avwebflash/news..._197531-1.html

This is a necessary step if GA is to survive past this century. The
technology is just getting started so things can only get better. With
piston engines, the good days are behind us.

Agreed.

With the ever increasing torrent of discoveries being made in physics,
I fully expect advancements in anti-gravity (not to mention quantum
computing) to occur before the end of the century. But I'm an
optimist. Just as likely, some fool will unleash the nuclear dogs of
war, and sterilize our planet.

That said, electrical propulsion does have the potential for three to
four times the efficiency (~90%) of internal combustion engines (~20%
to 30%). Unlike petroleum, sunlight is (for all practical purposes)
not a finite resource, and no nation or region has a monopoly on it.
Imagine a solar powered photovoltaic system on the ground that quietly
electrolyzes water into its constituent parts, hydrogen and oxygen,
percolating away all day long generating the fuel to run a fuel-cell
electric generator (with its exhaust consisting of only pure water).
Photo-cell technology (Spectralab) is currently approaching 40%
efficiency, and electric motors and controllers are =90% efficient,
so clean and quiet electric propulsion is clearly the future.

The application of electric propulsion for aviation today is in its
infancy, and only possible at all because of the technical
breakthrough provided by light Li-ion batteries enabling it. I look
for Li-Ion technology to steadily improve over time. As it is, the
individual cells used today are only approximately the size of common
AA batteries. Imagine the weight savings possible if larger cells
were produced; there would be significantly less steel jacketing
necessary. That said, it's difficult to imagine a battery with the
energy/power density of gasoline, so there will certainly be
tradeoffs.

Despite the fact that electric motors must use iron/steel in their
construction, they are significantly lighter (50%) than their
internal combustion counterparts. But when the wiring, controls,
batteries and perhaps fuel-cells are considered, I would guess the
weight of an electrically powered aircraft would be roughly comparable
to one powered by an internal combustion engine. So, with
significantly less power/energy density than gasoline, batteries will
not provide the same range/duration until they are improved further.
But it is encouraging to see progress being made at last.

Not going to happen.

Energy densities

fuel MJ/kg MJ/L

JET-A 43 33
ethenol 30 24
Li-ion battery (projected) 1 2
NiMH battery .2 .4
ultracapacitor .02 .05

Regenerative fuel cell come in a bit under 2 MJ/kg.

http://en.wikipedia.org/wiki/Energy_density

Electricity is great stuff, but damn awkward to carry around.

--
Jim Pennino

Remove .spam.sux to reply.

On Tue, 15 Apr 2008 01:05:04 GMT, wrote in
:


Despite the fact that electric motors must use iron/steel in their
construction, they are significantly lighter (50%) than their
internal combustion counterparts. But when the wiring, controls,
batteries and perhaps fuel-cells are considered, I would guess the
weight of an electrically powered aircraft would be roughly comparable
to one powered by an internal combustion engine. So, with
significantly less power/energy density than gasoline, batteries will
not provide the same range/duration until they are improved further.
But it is encouraging to see progress being made at last.

Not going to happen.


I hesitate to attempt to infer your meaning in that phrase, but if you
mean Li-ion batteries, perhaps. If you're referring to electrically
powered aircraft, they have already happened, and development is
progressing.

Energy densities

fuel MJ/kg MJ/L

JET-A 43 33
ethenol 30 24
Li-ion battery (projected) 1 2
NiMH battery .2 .4
ultracapacitor .02 .05

Regenerative fuel cell come in a bit under 2 MJ/kg.

http://en.wikipedia.org/wiki/Energy_density


Thank you for the factual data. It's interesting that gasoline is
omitted:

http://hypertextbook.com/facts/2003/ArthurGolnik.shtml
Liquid Fuel MJ/litre litre/Tonne GJ/Tonne MJ/kg
Gasoline, aviation 33.0 1412 49.6 36.4


Here's a little more data on Li-ion cells:

http://en.wikipedia.org/wiki/Lithium_ion_battery
Specific energy density: 150 to 200 Wh/kg (540 to 720 kJ/kg)
Volumetric energy density: 250 to 530 Wh/l (900 to 1900 J/cm³)
Specific power density: 300 to 1500 W/kg (@ 20 seconds and 285
Wh/l)



There's a great comparison chart of energy densities he

http://en.wikipedia.org/wiki/Energy_density


Here are a few of the entries:

Storage Type Energy Density By Mass (MJ/kg)
================================================== ================
lead acid battery 0.090.09–0.11[36]sm=n
lithium ion battery-present capability 0.230.23–0.28
lithium ion battery-predicted future capability 0.540.54–0.9sm=n
Regenerative Fuel Cell (fuel cell with internal Hydrogen reservoir
used much as a battery) 1.62
Lithium ion battery with nanowires 2.54-2.72
TNT 4.184
dry cowdung and cameldung 15.5
calcium (burned in air) 15.9
PET pop bottle plastic 23.5?23.5
ethanol 30
aluminum (burned in air) 31.0
Jet A aviation fuel 42.8
gasoline 46.9
compressed natural gas at 200 bar (2,900.8 psi) 53.6
compressed hydrogen gas at 700 bar (10,423.5054 psi) 143
Enriched uranium (3.5% U235) in light water reactor 3,456,000
nuclear fission (of U-235) (Used in nuclear power plants)
88,250,000


From the data in the chart it would appear that a best-case Lithium
ion battery with nanowires (2.54-2.72 MJ/kg) that would provide the
equivalent energy of a given amount of gasoline (46.9 MJ/kg) would
weigh 17.24 times as much as the gasoline it replaces. That doesn't
look too terribly feasible for aviation use. Oh well....

However, hydrogen gas compressed to a pressure of ~10,500 psi (143
MJ/kg) would only weigh ~1/3 as much as the equivalent gasoline energy
it replaces. If that hydrogen were used along with atmospheric oxygen
to produce electricity by a fuel-cell with a typical efficiency of
~36% http://en.wikipedia.org/wiki/Fuel_cell#Efficiency, and the
efficiency of the electrical motor, wiring, and controller were 90%,
and the weights of the total systems were roughly equivalent, it would
appear that there would be a close approximation of performance of
today's aircraft including waste heat, but not noxious emissions nor
noise. I'm not sure exactly how the overall efficiency would be
affected by the use of pressurized oxygen, or if both the hydrogen and
oxygen were produced by the electrolysis of water by photovoltaics.
(Now, if the compressed hydrogen were carried in a tubular wing spar,
imagine it's rigidity... /dream mode)

Of course these rough theoretical calculations are predicated on
existing technologies, and don't consider the inevitable future
technical advancements.

Thank you for providing the catalyst that led to this insight into the
issue.


Electricity is great stuff, but damn awkward to carry around.

So it appears.

Larry Dighera wrote:
On Tue, 15 Apr 2008 01:05:04 GMT, wrote in
:


Despite the fact that electric motors must use iron/steel in their
construction, they are significantly lighter (50%) than their
internal combustion counterparts. But when the wiring, controls,
batteries and perhaps fuel-cells are considered, I would guess the
weight of an electrically powered aircraft would be roughly comparable
to one powered by an internal combustion engine. So, with
significantly less power/energy density than gasoline, batteries will
not provide the same range/duration until they are improved further.
But it is encouraging to see progress being made at last.

Not going to happen.


I hesitate to attempt to infer your meaning in that phrase, but if you
mean Li-ion batteries, perhaps. If you're referring to electrically
powered aircraft, they have already happened, and development is
progressing.

Energy densities

fuel MJ/kg MJ/L

JET-A 43 33
ethenol 30 24
Li-ion battery (projected) 1 2
NiMH battery .2 .4
ultracapacitor .02 .05

Regenerative fuel cell come in a bit under 2 MJ/kg.

http://en.wikipedia.org/wiki/Energy_density


Thank you for the factual data. It's interesting that gasoline is
omitted:

As were many other things.


http://hypertextbook.com/facts/2003/ArthurGolnik.shtml
Liquid Fuel MJ/litre litre/Tonne GJ/Tonne MJ/kg
Gasoline, aviation 33.0 1412 49.6 36.4


Here's a little more data on Li-ion cells:

http://en.wikipedia.org/wiki/Lithium_ion_battery
Specific energy density: 150 to 200 Wh/kg (540 to 720 kJ/kg)
Volumetric energy density: 250 to 530 Wh/l (900 to 1900 J/cm?)
Specific power density: 300 to 1500 W/kg (@ 20 seconds and 285
Wh/l)



There's a great comparison chart of energy densities he

http://en.wikipedia.org/wiki/Energy_density

Which is where the above came from.


Here are a few of the entries:

Storage Type Energy Density By Mass (MJ/kg)
================================================== ================
lead acid battery 0.090.09?0.11[36]sm=n
lithium ion battery-present capability 0.230.23?0.28
lithium ion battery-predicted future capability 0.540.54?0.9sm=n
Regenerative Fuel Cell (fuel cell with internal Hydrogen reservoir
used much as a battery) 1.62
Lithium ion battery with nanowires 2.54-2.72
TNT 4.184
dry cowdung and cameldung 15.5
calcium (burned in air) 15.9
PET pop bottle plastic 23.5?23.5
ethanol 30
aluminum (burned in air) 31.0
Jet A aviation fuel 42.8
gasoline 46.9
compressed natural gas at 200 bar (2,900.8 psi) 53.6
compressed hydrogen gas at 700 bar (10,423.5054 psi) 143
Enriched uranium (3.5% U235) in light water reactor 3,456,000
nuclear fission (of U-235) (Used in nuclear power plants)
88,250,000


From the data in the chart it would appear that a best-case Lithium
ion battery with nanowires (2.54-2.72 MJ/kg) that would provide the
equivalent energy of a given amount of gasoline (46.9 MJ/kg) would
weigh 17.24 times as much as the gasoline it replaces. That doesn't
look too terribly feasible for aviation use. Oh well....

Or any other vehicle.

Another limitation is that for something the size of a C-172, your
battery has to deliver around 120 kW to get off the ground and
climb to altitude.

However, hydrogen gas compressed to a pressure of ~10,500 psi (143
MJ/kg) would only weigh ~1/3 as much as the equivalent gasoline energy
it replaces. If that hydrogen were used along with atmospheric oxygen
to produce electricity by a fuel-cell with a typical efficiency of
~36% http://en.wikipedia.org/wiki/Fuel_cell#Efficiency, and the
efficiency of the electrical motor, wiring, and controller were 90%,
and the weights of the total systems were roughly equivalent, it would
appear that there would be a close approximation of performance of
today's aircraft including waste heat, but not noxious emissions nor
noise. I'm not sure exactly how the overall efficiency would be
affected by the use of pressurized oxygen, or if both the hydrogen and
oxygen were produced by the electrolysis of water by photovoltaics.
(Now, if the compressed hydrogen were carried in a tubular wing spar,
imagine it's rigidity... /dream mode)

You are forgetting about the enormous weight of a tank capable of
containing hydrogen at 10,500 psi as well as the problem of hydrogen
embittlement at those pressures.

The very last thing you would want to do is put it in a wing spar.

Of course these rough theoretical calculations are predicated on
existing technologies, and don't consider the inevitable future
technical advancements.

Which are no better than a wish and a hope in the real world.


Thank you for providing the catalyst that led to this insight into the
issue.


Electricity is great stuff, but damn awkward to carry around.

So it appears.

--
Jim Pennino

Remove .spam.sux to reply.