Alternative to the Battery wows?

Ran across this short article about an interesting project at the Delft University in The Netherlands:
https://www.yahoo.com/lifestyle/dutc...153606032.html

Uli
AS

On Monday, 8 March 2021 at 18:26:28 UTC, AS wrote:
Ran across this short article about an interesting project at the Delft University in The Netherlands:
https://www.yahoo.com/lifestyle/dutc...153606032.html

Uli
AS
Easy to tell it's H-powered ... look at all the water vapour it's left behind! ;-o)

wrote on 3/8/2021 10:35 AM:
On Monday, 8 March 2021 at 18:26:28 UTC, AS wrote:
Ran across this short article about an interesting project at the Delft University in The Netherlands:
https://www.yahoo.com/lifestyle/dutc...153606032.html

Uli
AS
Easy to tell it's H-powered ... look at all the water vapour it's left behind! ;-o)

The article startles with the announcement the aircraft will have a 164 foot wingspan! Better
to use the developers' website at ...

https://aerodelft.nl/project-phoenix/

.... where you learn it is an 18M wingspan. Hydrogen aircraft have flown before, but I don't
know if any used liquid hydrogen. I did see recently that Toyota is offering the hydrogen
fueled Mirai sedan for 2021. For our electric gliders, batteries will remain the best choice
because energy density is not critical, as it is for airplanes.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

https://www.ebay.com/itm/40271384237...d2e50c37173811

How about just scale this up a bit.
Already available technology , it works great!
Available right off the shelf.
No fire problem.
No carbs or FI to fiddle with.
I think you can buy a folding nose prop today.
Just run a piece of 6" PVC under your seat run the rubber band nose to tail and wind it up.
Nick
T

I recommend doing a bit of research into how hydrogen is produced (mostly) from fossil fuels. Methane (or "clean-burning Natural Gas") is the primary source, and the process is pretty energy intensive. Electrolysis is possible, but at lower energy efficiency.

Storage of gaseous hydrogen to the typical 5,000 to 10,000 psi used is a very real energy and safety concern. Liquefaction is more energy intensive and much less safe due to the refrigeration required to keep the hydrogen from "boiling off" and producing an extremely combustible cloud. Lose the refrigeration and you are in for a real treat. Hydrogen molecules are so small that they leak through anything.

Storage by adsorption (not absorption) in metal hydrides is much safer, but requires significant energy to store the hydrogen and then release it for use. Add in the cost of building an entirely new infrastructure to produce, store and deliver hydrogen as a fuel and the "clean" benefits are quickly outweighed by the need to build the infrastructure using conventional energy sources, i.e. oil & gas.

And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide.

In short, hydrogen is not the super-simple solution to all of the world's problems, and could, in fact, exacerbate them.

Mark Mocho wrote on 3/8/2021 11:34 AM:
And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide.

Not so much when it comes to climate change, because as water vapor increases (primarily due to
global warming), it forms more clouds, which reflect the heat, tending to reduce global warming
- all part of a natural cycle that's be going on since the earth began. CO2 does not condense,
and we are adding it to the atmosphere at a far higher rate than natural carbon sinks can
remove it.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Monday, March 8, 2021 at 1:42:45 PM UTC-7, Eric Greenwell wrote:
Mark Mocho wrote on 3/8/2021 11:34 AM:
And I seem to remember hearing that water vapor is more of a "greenhouse gas" than carbon dioxide.
Not so much when it comes to climate change, because as water vapor increases (primarily due to
global warming), it forms more clouds, which reflect the heat, tending to reduce global warming
- all part of a natural cycle that's be going on since the earth began. CO2 does not condense,
and we are adding it to the atmosphere at a far higher rate than natural carbon sinks can
remove it.
--
However, using hydrogen as an alternative fuel WILL add to the amount of water vapor in the atmosphere. Note the following statement:

"...water vapor is the largest contributor to the Earth’s greenhouse effect...However, water vapor does not control the Earth’s temperature, but is instead controlled by the temperature...If there had been no increase in the amounts of non-condensable greenhouse gases (like carbon dioxide), the amount of water vapor in the atmosphere would not have changed with all other variables remaining the same." (from the American Chemical Society's ACS Climate Science Toolkit)

The key phrase is the last one: "with all other variables remaining the same." Imagine that instead of seeing "normal" contrails behind a high flying airliner, there is a huge plume of water vapor that results from burning hydrogen. That definitely adds to atmospheric water vapor, independent of the natural evaporation/condensation cycle that forms clouds.

Of course, the "Chemtrails" paranoids will get a corresponding boost in popularity.

On 3/8/2021 1:53 PM, Eric Greenwell wrote:
wrote on 3/8/2021 10:35 AM:
On Monday, 8 March 2021 at 18:26:28 UTC, AS wrote:
Ran across this short article about an interesting project at the
Delft University in The Netherlands:
https://www.yahoo.com/lifestyle/dutc...153606032.html


Uli
AS
Easy to tell it's H-powered ... look at all the water vapour it's left
behind!Â* ;-o)

The article startles with the announcement the aircraft will have a 164
foot wingspan! Better to use the developers' website at ...

https://aerodelft.nl/project-phoenix/

... where you learn it is an 18M wingspan. Hydrogen aircraft have flown
before, but I don't know if any used liquid hydrogen. I did see recently
that Toyota is offering the hydrogen fueled Mirai sedan for 2021. For
our electric gliders, batteries will remain the best choice because
energy density is not critical, as it is for airplanes.

"Hydrogen is kept in a cryogenic tank at -253°C and warmed to 0°C using
a complex tubing system."

The hydrogen may be light, but the cryogenic tank isn't. Hydrogen is
notoriously difficult to store in a dense form. If you can make a fuel
cell affordable (big if), there are better fuels for the purpose, that
store as a liquid in ambient conditions or mild pressure, e.g.,
methanol, ammonia... (All of which can in theory be produced using
solar power, but don't hold your breath, it's makes no sense economically.)

That's terrific! The energy content in H2 beats anything except nuclear
power, and wouldn't it be great to fly a 72 ton glider around with
unlimited launch and retrieve capability? But one statement in the
article has me perplexed:

"Current hydrogen extraction is highly energy intensive, so ways to
harvest “green hydrogen� using water electrolysis are being explored."

I believe that it takes more energy to extract the hydrogen from water
than is realized by burning the hydrogen. I have no idea of the energy
cost to liquefy and distill hydrogen. Can anybody shed some light on
that? I can see giant smoke stacks spewing sooty black smoke into the
air due to burning coal to generate the electricity to compress the air
to harvest the hydrogen. Well... Maybe not. Perhaps covering Europe
with wind mills to make the electricity and using sailing ships to
deliver the H2 around the world.

Credit to Dr. Seuss and Rube Goldberg for the inspiration.

Dan
5J

On 3/8/21 11:26 AM, AS wrote:
Ran across this short article about an interesting project at the Delft University in The Netherlands:
https://www.yahoo.com/lifestyle/dutc...153606032.html

Uli
AS

On Tuesday, 9 March 2021 at 16:24:12 UTC, Dan Marotta wrote:
That's terrific! The energy content in H2 beats anything except nuclear
power, and wouldn't it be great to fly a 72 ton glider around with
unlimited launch and retrieve capability? But one statement in the
article has me perplexed:

"Current hydrogen extraction is highly energy intensive, so ways to
harvest “green hydrogen� using water electrolysis are being explored."

I believe that it takes more energy to extract the hydrogen from water
than is realized by burning the hydrogen. I have no idea of the energy
cost to liquefy and distill hydrogen. Can anybody shed some light on
that? I can see giant smoke stacks spewing sooty black smoke into the
air due to burning coal to generate the electricity to compress the air
to harvest the hydrogen. Well... Maybe not. Perhaps covering Europe
with wind mills to make the electricity and using sailing ships to
deliver the H2 around the world.

Credit to Dr. Seuss and Rube Goldberg for the inspiration.

Dan
5J
On 3/8/21 11:26 AM, AS wrote:
Ran across this short article about an interesting project at the Delft University in The Netherlands:
https://www.yahoo.com/lifestyle/dutc...153606032.html

Uli
AS

It looks like covering Saudi Arabia with solar panels is the way!

https://tinyurl.com/3kjwd6nf