What Color is Your Hydrogen?

Whenever anyone used to tout the virtues of hydrogen, I would quote Switch from "The Matrix," whose first words to Neo were "Listen up, Coppertop," telling him that he is nothing more than a battery.

Green Hydrogen

That's because "green" hydrogen is made by splitting water into hydrogen and oxygen with lots of electricity. The H2 then has to be compressed, stored, and if used in cars, converted back into electricity in a fuel cell vehicle (FCV). Every step of the process wastes energy, much more than when you put that electricity into a battery-powered electric vehicle (BEV). According to James Morris in Forbes, "for every kW of electricity supply, you get 800W for a BEV, but only 380W for an FCV – less than half as much." Hydrogen, like Neo in the Matrix, makes a terrible battery.

Gray Hydrogen

The other problem with hydrogen is that only about ONE PERCENT of it is green. (Sources vary on this, others claim as much as 4%.) Much of the rest is made through the steam reforming of natural gas (CH₄ ) which releases 9.3 kilograms of CO2 for every kilogram of H2 (this is called "gray" hydrogen). So every time they show the amazing hydrogen-powered train of the future in Germany, they are really showing a natural gas-powered train on a line which they don't want to spend the money to electrify. More Hydrogen Hype.

When you ask anyone in the hydrogen game about this, they say don't worry, it is just an interim step on the way. From Bloomberg:

“Long-term, only green hydrogen from electrolysis via renewable energies will allow for a truly climate-neutral solution,” said Bernhard Osburg, chairman of the executive board at Thyssenkrupp Steel. “But other types of hydrogen can help to establish a market.”

The problem with this, as Vanessa Desem writes in the same Bloomberg article, is that "for hydrogen from water electrolysis to reach a quarter of the world’s energy needs, it would require more power than the total global electricity generation in 2019."

Blue Hydrogen

There is a third option that's being pushed by the fossil fuel industry, where the hydrogen is produced through steam reforming like the gray hydrogen, but then the CO2 is captured and stored.

“Blue hydrogen can replace fossil fuels with limited extra costs and if you do it in a large scale, you are able to take out a big chunk of emissions,” Grete Tveit, senior vice president for low carbon solutions at Equinor, said by phone. “For big emitters, that is a fast and cheaper solution.”

This is the point: it keeps the big emitters – the shale frackers and the gas companies and the distribution companies – in the game. According to Will Mathis in Bloomberg,

Blue hydrogen could be a particularly effective tool for oil and gas companies looking to re-purpose their existing investments—namely pipes. The same infrastructure that today carries natural gas up to the surface could instead be used to move carbon dioxide in the opposite direction.

In countries like the UK, where the vast majority of homes are heated by gas and almost everyone cooks with it, this is an attractive solution. “The attraction of hydrogen is that for a lot of consumers, they wouldn’t notice any difference. Customers would continue to use a boiler to heat their homes in a similar manner to natural gas,” says Robert Sansom of the Institution of Engineering and Technology’s energy policy panel in the Guardian. The gas companies are pushing hard on this:

According to Chris Goodall, energy economist and author of What We Need to Do Now for a Zero Carbon Future, it is a matter of survival. “They do not wish for their industry to be eaten up by a switch to electricity for heating. So they are moving as fast as they can to persuade us about hydrogen,” he says.

P2G (Power To Gas)

This is apparently another name for Green Hydrogen, used by the Debate.Energy website sponsored by UNIPER, a big German energy company. It makes the point that as we keep building renewable energy sources like wind power to meet peak loads, there is going to be lots of extra capacity in off-peak times. Pumping it into giant electrolyzers could eat up all that power and turn it into Green Hydrogen. Thomas Schmidt describes a proposed installation in Germany:

The world’s largest P2G plant is planned for the port of Hamburg, Germany. The plant would will cost €150 million to build and have a capacity of 100 megawatts (MW), ten times more than the biggest existing P2G plants. It will use surplus wind power to produce, according to turbine manufacturer Siemens, about 2 metric tons, or 22,000 cubic meters, of hydrogen per hour. The hydrogen will fuel gas-fired power plants to generate electricity for nearby industrial enterprises that produce copper, steel, and aluminum.

Does this make sense? It's still awfully expensive electricity. Using the gas directly to replace coke in steel manufacture seems far more logical, as does smelting aluminum in Norway or Iceland with hydropower.

I also wonder how much surplus electricity there is going to be when more of the population is driving battery-powered cars and charging them in off-peak hours, or using heat pumps with thermal batteries for heating their homes.

Is it all Just Hydrogen Hype?

There is no question that there is going to be an ever-increasing amount of surplus off-peak power to be sucked up by something, that electrolyzers are becoming cheaper and more efficient, and that hydrogen is useful stuff, mostly now going into industrial processes like making fertilizer.

But I remain skeptical, still thinking that this hydrogen economy is still little more than a last-ditch attempt by the big established energy and fossil fuel companies to stay relevant in an electrifying world.

Disclosure: I have been an admirer of UNIPER's new CEO, Andreas Schierenbeck, who I met many times as his guest when he was CEO of ThyssenKrupp Elevators. I also think their new website Debate.Energy, "a forum for scientists, experts, business leaders, policymakers, and cultural theorists to share their views on one of this era’s most important issues: the transformation of the energy system," is a site worth watching – it is a great debate to have. I remain willing to continue this debate and be convinced.