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Old September 28th 20, 04:57 PM posted to rec.aviation.piloting
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Default First Commercial-Grade Aircraft Flies On Hydrogen Fuel Cells

Larry Dighera wrote:

"It uses solar energy to drive electrolytic converters to produce
gaseous hydrogen for use in the cold fuel cells"

Hey, I've heard that approach to electric motive power someplace
before. :-)

Like Jim said in another message thread, hydrogen research was done
extensively decades ago. But the efficiency of electrolysis, fuel
cells and photovoltaics have vastly improved to the point today where
hydrogen power is now evidentially feasible, at least experimentally.
But this is only the beginning of gaseous hydrogen (H2) powered
aircraft technology.

The future is Liquid H2 (LH2) that contains three-times the energy
density of gasoline, and is three times lighter in weight. Together
with today's efficient cryocooler technology
https://link.springer.com/chapter/10...306-47112-4_10 and
high-efficiency solar panels, the production of liquid hydrogen from
water will soon revolutionize electric motive power throughout the
world all without producing any environmentally harmful byproducts.


Don't hold your breath.

High efficiency solar cells means about 25% efficient, up from the
previous 15% of twenty years ago.

However, the absolute maximum efficency for silicon cells, limited
by the laws of physics, is 29.43%.

Using concentrators, i.e. lenses and mirrors, GaAs cells in labratories
have achieved about 35%.

Commercially available solar cells max out at about 20%.

snip

While the efficiency of photovoltaics may be only around 20% to 30%
efficient, they operate for decades without any moving parts,


At continuously declining efficiencies and require constant cleaning.

Don't forget the cost of land which will get you about 1 kW of raw
solar energy per square meter at Noon on a clear day in the South
West, or about 200 W after conversion.

Just like fusion, solar energy and hydrogen will be here any day
now...


--
Jim Pennino