[Worldtraveler once upon a time]

And how is the hydrogen generated? Through the large use of other forms of energy. Most hydrogen generation uses "hydrocarbon" energy in the moment. Some small attempts to use hydroelectric are also underway. But hydrogen generation is VERY energy demanding. So the "zero" marketing is just that.

M A R K E T I N G

And behind the scenes? Grants and subsidies from government.

[Gen.Blather]

My college thermo class was taught by a genuine NASA scientist. He had the class work through complicated applications of all the Green energy schemes we see today. Even given the most generous assumptions none of them beat just using plane old oil-based energy.

[BipolarBob]

It’s not zero emissions, it’s remote emissions.

[Gaffer]

They wouldn’t be generating hydrogen on the spot (i.e., in the plane). Likely, it would be hydrogen introduced from storage tanks on the ground into the plane, and it would either be highly compressed or more densely stored in some sort of metal hydride material where the stored hydrogen could be released as needed by heating.

[Glad2bnuts]

In WA, they are using our local coal fired plant to make and test hydrogen production. Funded by $.50 a gallon tax on gas, and will switch to hydro power after a bit, to produce it.

How much legacy fuel does it take to get the equal amount of energy potential out of hydrogen? If I remember right, 3 gallons of diesel to make 1 gallon of hydrogen. In short, it is a source of more pollution. Like ethanol, it takes 1.5 gallons of diesel to produce 1 gallon of ethanol, and you get worse mileage with it. Plus the millions of gallons pumped from aquifers for watering corn, and producing alchohol/ethanol.