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United Airlines plans to purchase up to 100 hydrogen-electric engines

United CEO Scott Kirby says hydrogen-electric engines are “one of the most promising paths to zero-emission air travel for smaller aircraft.” While there is excitement in some quarters regarding the potential of new, lower-emission forms of aviation, some within the industry are more circumspect about how such innovations will develop over the coming years. ( More...

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Greg Cotten 7
As a PhD Chemical Engineer, I can assure everyone that the Hydrogen “fuel” story is very mis-leading. It is not a natural fuel like coal, crude oil, and natural gas, but rather a chemical plant product.

Hydrogen comes from three main methods and are all energy consuming!
1) methane (natural gas)
2) coal gasification..duh from coal
3) electrolysis (water and a bunch of electricity)

We are not making any more methane, coal, or water on Earth in anything other than geologic time scales, long after homo sapiens is gone, so to say you are “neutral” is simply false advertsing.
Tim Dyck 1
When made from water it is replaced with the water created when it is converted to electricity. I won’t claim to know the whole process of how a fuel cell works but the technology has been around for decades.
Peter McGrath 2
So, when Hydrogen "combusts", the most common substance resulting is water. The hydrogen atoms mix with the oxygen atoms and create the essential H20 formula, resulting in a light residue of water that may escape as water vapor or condense on surfaces near where the hydrogen is burned. Imagine a plane at 40,000 feet covered in a "light residue of ice"! I think this is one of the reasons they've never developed this for autos. In warm climates, it would be great, but imagine water dripping from exhaust pipes in North Dakota in January!
Tim Dyck 2
First off Hydrogen is not “burned” in a fuel cell it is converted to electricity. Because it is producing electricity propeller driven aircraft just use electric motors to turn the props and the fuel cells do not need to be out on the wings.
Boeing first flew a Fuel Cell powered plane in 2008 and has continues to experiment with them as technology develops. Lockheed Martin has been using fuel cells in UAVs for over a decade so the use of fuel cells in aircraft is proven but the logistics of transporting and storing fuel remain.
Also of note but not aviation related both the German and Italian navies use fuel cells to power the Type 212 submarines. This enables them to remain submerged for extended periods of time without a nuclear reactor.
Tim ONeill -1
From the original article--

"As concerns about sustainability and the environment mount — the World Wildlife Fund describes air travel as “the most carbon intensive activity an individual can make” — discussions around aviation are increasingly focused on how new tech and ideas could cut its environmental footprint."

When did the WWF become an expert on aviation emissions?

Didn't United recently fly what was reported as "the first 100% biofuel-powered flight"? But it really wasn't 100% biofuel powered, one engine operated on biofuel (at about $40/gallon) while the other burned kerosene Jet A (about $3/gallon). Again, we see that when it comes to "climate" we don't get the whole picture from the climate nazis and their media lapdogs.

We are deceiving ourselves to think human activity affects global climate and that we should kill our economies to fix it--the climate predictive models are fraudulent. There is no doubt global warming is occurring (which may actually be a good thing from a food production standpoint) but it is more-likely caused by natural cycles of that fireball that rises daily in the East and sets in the West. Anyway, the climate nazis have ended all debate by declaring it "settled" because the UN IPCC says so and governments worldwide fund studies with grants awarded to those that conclude man-made activity is the cause to further their destructive agendas.

"Green" energy is a similar farce, there is no free lunch. The cost of "Sustainable" jet fuel is astronomical compared to kerosene and really, the amount of carbon dioxide produced by aviation worldwide amounts to a fart in a whirlwind.

In the automotive world, where is all the electricity going to come from to charge the lithium ion batteries used in EVs? Not from solar panels (which use toxic cadmium as a major component of photovoltaic cells produced in China--use of cadmium plating in aerospace was banned about 20 years' ago) and wind turbines (currently no practical way to recycle the massive propeller blades other than landfilling). Natural-gas fired turbine generating power plants are very clean and scalable, and natural gas is abundant but the climate nazis say no to this as well. I see Teslas at the charging stations now in the US Midwest with the owners sleeping or reclined reading a book for the 3 hour recharge. And let's talk about how "green" mining operations for lithium are in China which is the primary source of the lithium used in EV Li-on battery packs.

Hydrogen is a laudable future goal and should be pursued, but there are significant metallurgical challenges to be overcome before hydrogen use is widespread.

We need to be smart about how we manage technological change particularly when acquiescing to the demands of a small but vociferous minority will destroy economies worldwide and put us back in the Stone age--but maybe that is their goal. Despite it's flaws, commercial aviation is a magnificent industry--the technology and reliability of todays jets large and small that routinely fly safely anywhere in the world is nothing less than awesome.

Ken Menningen 4
I believe healthy skepticism is good. I also agree the press tends to fixate on the negative effects of global warming, rather than the positive (such as food production), partly due to human nature and partly because bad news sells better. So does hyperbole. (Such as fighting climate change will "put us back in the Stone age." That claim is as absurd as other claims that global warming will make our planet unlivable. Neither are likely to happen.) You are also correct to say there is no "free lunch," green energy comes with problems that many people are trying to figure out how to mitigate.

But it is not helpful to make dogmatic pronouncements (such as human activity cannot affect global climate) that dismiss or ignore evidence to the contrary. Reality is complicated.

I have three remarks about your scientific claims. First, I suspect you believe IPCC are all liars, but if you entertain the notion for a moment that they are actually competent scientists, they did examine the question whether solar cycles are driving global warming instead of greenhouse gases. If you examine box TS.5, figure 1 ( they examine volcanic eruptions, total solar irradiance (TSI), and greenhouse gases (GHG) in the top graph (a). Which of these is correlated to the temperature graph (b)? Not solar irradiance.

Second, while it is true that many low-cost solar cells are based on CdSe, most solar panels these days are silicon based. I admit that manufacture of silicon solar panels still involves toxic materials, but in sufficiently small amounts they do not pose a comparable pollution threat to many other industries.

Third, while natural gas plants are "clean" when compared to coal-fired plants, and will definitely remain part of our electricity grid infrastructure for decades, they still take ancient carbon buried far underground and spew it into our atmosphere to the tune of billions of tons per year. The atmospheric carbon dioxide levels have increased from 270 ppm to 420 ppm over the past century, in part due to humans and in part due to warming oceans. In any case, it is not wise to nearly double carbon dioxide levels without worrying about the possible ill effects that may occur.

I agree with you that "hydrogen is a laudable future goal and should be pursued." I also agree "we need to be smart about how we manage technological change!" Let's keep on working on new propulsion technologies that can reduce the environmental impact of aviation.
Tim Dyck 1
Wile the IPCC reports are based on science they are written for politicians. If you read the reports as I do whenever one is released you will find numerous references to the scientific papers quoted or all to often misquoted. The authors of the IPCC reports cherry pick the data that fits their agenda and ignor data that refutes them. Many authors of scientific papers have complained about this but the media doesn’t bother with that and instead cherry picks what they want from the reports. Bad news sells copy so that is what they look for. Sadly by the time it gets to the majority of the public it is more disinformation then actual information.
Solar power has a place in our future but unlike many critics I don’t dwell on the recyclability of components, my concerns are efficiently and the amount of land needed to produce substantial amounts of electricity from solar. This will become less as technology develops more efficiency and I think solar will have a place in the future.
Natural gas also has a place in the future. And remember the CO2 in all fossil fuels used to be in the atmosphere but was sequestered millions of years ago. Looking at the past to when that happened we did not have a dead planet but one that teamed with life in a warmer climate. Again the IPCC reports and the media articles often lean towards fear mongering and driving the idea that a warmer planet isn’t good but a look at the past to any time the planet was warmer it was also a better place for life. People have chosen to live in fear of the unknown instead of looking at to potential of a better climate.
Thanks for your post. It was well written and well thought out. Even if I don’t agree with all your points I appreciate that you put together a good post and used facts and logic instead of the personal attacks we all too often see today. Have a great day.
Mike Taylor 1
I believe studies have shown that the effects of carbon dioxide concentrations on the climate are not linear. That is, a doubling of the ppm does not have a doubling effect but one that is much less than expected.
David Tsai 2
I can't account for potential misquotes, but United did not say that the flight was "100% biofuel-powered." They said that it was using "100% sustainable aviation fuel" in that the fuel that was sustainable was 100% sustainable, not that the flight was using 100% fuel that was sustainable.

Next, I don't know about killing the economy. With more research, alternative fuels could be cheaper, which would be good for the economy. I would say that it's not foolish for those with deep pockets to fund such research.
Don Whyte 1
mike moseley 1
That aviation fuel costs $3 a gallon to the airlines is not the real "cost". Fossil fuels are heavily subsidized through direct tax incentives, require trillions of dollars in military funding to protect the extraction process and supply chain, and incur incalculable costs in money, lives and untold human suffering due to anthropogenic induced climate change. Climate change is accelerating and whatever the real cost of kerosene and other carbon-based fuels are in today’s dollars will be exponentially more than the costs to move to carbon free, renewable energy sources. Change is tough, but inevitable and will happen sooner or later. It would appear that some of those in the airline industry are thinking long term.
Mike Mohle 0
Right on Tim, Greta needs to read this and wake up, but instead she will say "If we can save just 1 polar bear it is all worth it" LOL
Tim Dyck 1
Are the Polar Bears really threatened? If so why are their populations up? Go to the Arctic and talk to the people there, especially the scientists studying the pPolar Bears, they will tell you a differant story then the media publishes.
I don't believe the Polar Bears are truly at risk. They haven't been around that Long. It's my understanding, based on research that suggests Brown Bears became isolated by ice sheets. They evolved to exist in Polar regions by adapting to their new environment. As the world became icebound the adaptations resultedin a new species. So it stands to reason that any significant warming would result in further adaptation. Or possibly not, survival or extinction is always a possibility that is attached to the concept of life
Bruce Horwitz 0
When did you become an expert on climate change AND aviation emissions AND photovoltaic cells? Just askin'
Tim Smith -6
Excellent Tim!
Would you mind sending a copy to Al Gore and the Hollywood elite?
skylab72 0
Anyone is deceiving themselves to think human activity does not affect global climate, and an economy is not "killed" by fixing profitability issues, it will grow because of it. Climate predictive models are estimates, and they have proven remarkably accurate. I'm sorry your buggy whip and harness business went bust, but petroleum is FAR too valuable as a raw material for manufacturing, to allow it to be burned for fuel. Good business is building a value engine that can sustain long-term profitability! Join us in the 21st Century.
Hydrogen = electricity = fossil fuel. What is the point?
Bruce Horwitz 2
Amazing, the issue is reduced to a simple one-line equation. Seriously, at this time we are still in the development stage of multiple technologies which might help reduce our headlong rush over the cliff. To suggest that any particular development effort has no point is a misunderstanding of how science and technology evolve.

And let me suggest an edit to your equation: Hydrogen = electricity = energy source, where the energy source may or may not be fossil fuel and even if it is how you do that conversion can may a big difference in greenhouse gas emissions.
Agreed Bruce, what viable energy source is available in 2021 to produce the electrical demands of a electrolysis plant to produce the hydrogen? I can think of only 2: natural gas and nuclear power plants. I think the issue is not can it be done but is it cost efficient from an environmental standpoint when considering the total impact of all the needed components to make it work. My personal opinion is that our government and interested corporations should be funding R&D to solve the outstanding issues of power storage ( battery hydrogen fuel cell etc) and realistic green power source for the electrical demands of the future.
Tim Dyck 2
One thing hydrogen is good for is storing energy. One of the flaws of solar and wind is the sun does not always shine nor the wind blow so it is kinda useless on a grid because you need a constant back up of base load and that kinda leaves the solar and wind redundant. But you could use solar and wind to convert water to hydrogen and then use it as an energy source that has a steady output.
bentwing60 -8
UAL's new fight song, "We are the Virtue Signalers of the World"!
I know, right? Sickening. So sick of hearing all of it from the woke b/s, green crap that is unreliable, political correctness and gender confusion! The left's goal is to just crash society and the economy to make everyone suffer. That way they can "rebuild", throwing the original Constitution in the fire. They don't care if this green crap even works. They'll just ram it down everyone's throat anyway. Blinded by bribes from wealthy leftists. Sad times we live in!
btweston -1
Yeah. Grumble grumble.


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