The New York Times reports on a huge project in Australia to produce green hydrogen, but correctly the article points our a number of doubts about whether hydrogen is the panacea that its proponets claim it to be.  The project envisions an enormous amount of land devoted to solar and wind power to produce the hydrogen.  The area is already important for its steel production.  Much of the hydrogen would be used there for iron ore mining and steel production.  Some would be exported. 

The electricity is needed to separate water into its components, hydrogen and oxygen.  Burning hydrogen just reunites it with oxygen and so it produces only water as its waste product, no carbon dioxide or other climate damaging gases.  However, it requires a lot of energy to separate the hydrogen from the oxygen in water. 

I see hydrogen as mainly a way to transfer energy.  Steel mills don’t run efficiently on electricity. Burning hydrogen could replace the current fossil fuels used, whether natural gas or coal.  Hydrogen can also be burned in internal combustion engines, or used to produce electricity with fuel cells.  Hydrogen can also be shipped from places with abundnnt sunlight and wind, like Australia, to places with less, like northern Europe.  However, shipping hydrogen is also not easy.  As a gas it must be cooled to almost absolute zero to be liquified.  It can be converted into ammonia, which is easier to ship, but at the receiving end, the ammonia must be reconverted into hydrogen. 

Overall, it is questionable whether hydrogen is the most efficient way to transfer energy.  It may make more sense to use hydrogen where it will be produced in Australia to run the steel mills and iron ore mining operations.    

Today, most hydrogen is blue hydrogen produced from climate destroy\ing natural gas, rather than the green hydrogen to be produced cleanly in Australia. 

The NYT article says:

For green hydrogen to have a substantial climate impact, its most essential use will be in steel making, a sprawling industry that produces nearly a tenth of global carbon dioxide emissions, more than all the world’s cars.

In climate lingo, steel emissions are “hard to abate.” Blast furnaces, freight trains, cargo ships and the gargantuan trucks used in mining require heavy fuels like coal and oil. Even if they could be electrified (and, as a practical matter, today many can’t be) they would strain grids enormously…

.One of the impediments to huge green hydrogen projects is the short supply of electrolyzers, the machines that use electricity to split water molecules apart, isolating the hydrogen.

One issue is that China, which produces most of the world’s solar panels, wind turbines and renewable energy tech, hasn’t embraced electrolyzer production. Analysts said there was a shrewd calculus to that: China is heavily invested in coal, and much of that is tied to steel and cement production.