Larry Dighera wrote:
On Sun, 7 Sep 2014 23:52:34 -0000, wrote:

Larry Dighera wrote:


http://www.avweb.com/avwebflash/news/Team-Aims-To-Fly-300-MPH-On-Batteries222710-1.html

Electroflight Team Aims To Fly 300 MPH On Batteries

Whoopee.

Let me know when they can fly 4 hours at at least 120 knots.

Hello Jim,

I recall researching this with you some years back in this newsgroup.
Technology is advancing, and hydrogen powered fuel cell based electric power is
on the horizon.

Yep, right around the corner along with cheap fusion power, true artificial
intelligence, a cure for the common cold and peace in the Middle East.

At the 2014 Consumer Electronics Show I spoke with Toyota engineer Ms. Jackie
Birdsall about Toyota's FCV concept car on display there. Here's link to a
video: https://www.youtube.com/watch?v=2bluUNxVLhE. She told me that their
fuel cell was 60% efficient in producing electricity from oxygen in the air and
compressed hydrogen; this is in contrast to ~30% efficiency of internal
combustion engines. If true, that will enable this technology to surpass

Efficiency has never been a particular issue, it has alway been energy
density, and for airplanes, that is both by weight and volume.

And to have an apples to apples comparison you have to include all the
support pieces like tanks and delivery equipment.

current propulsion technology. She also said the hydrogen would be compressed
to ten bar, which would raise its energy density comparable to that of
gasoline. So, it would appear that your dream specifications could be
achievable soon.

That's OK for a car, but a 145 psi hydrogen tank after the FAA gets done
with the requirements is not going to be particularly light.

There is also the issue of tank life. Tanks for compressed gas of any kind
are typically subject to periodic static testing and/or replacement.

I just can't see how all that is going to be practical in an aircraft
wing.

Best regards,
Larry

I'm not going to be holding my breath...



--
Jim Pennino