Clean Energy Superstar or Smokescreen for Fossil Fuel Use? Here’s What You Need to Know about Hydrogen.

by Tik Root (Washington Post) ... But some urge caution, noting that almost all the hydrogen currently produced is derived from fossil fuels, especially natural gas. And a study published last year found that, if those embodied emissions are considered, purportedly “clean,” hydrogen can have a greater climate impact than natural gas or oil.

Here are some answers to questions about hydrogen fuel.

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Hydrogen can be burned, or combusted, similar to natural gas or oil. It can also be used in “fuel cells,” where hydrogen and oxygen mix in a reaction that creates electricity. And there is a litany of both realized and proposed uses for hydrogen, from heating homes to powering airplanes.

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According to the IEA, hydrogen production relies “almost entirely” on fossil fuels, particularly natural gas.

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Hydrogen is commonly referred to on a color spectrum, and when produced from natural gas it’s known as “gray” hydrogen. There is also “blue” hydrogen, which also uses natural gas, but the carbon dioxide that’s released during the process is, to varying degrees, captured instead of emitted.

It’s also possible to use electricity to split water into hydrogen and oxygen — ideally using electricity from renewable sources. “On the color spectrum, that’s green hydrogen,” said Frank Wolak, president of the Fuel Cell and Hydrogen Energy Association.

There are a number of other stops on the color wheel as well, such as “brown” hydrogen, which comes from coal gasification, and “pink” hydrogen, which is produced when the electricity comes from nuclear power. But, whatever the nomenclature, the resulting hydrogen is molecularly the same.

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How climate-friendly and efficient is hydrogen?

The potential emissions savings from hydrogen is broadly a function of how it’s produced, how it’s used and what energy source it’s replacing.

With a hydrogen fuel cell, the only emissions are water vapor. Greenhouse gas emissions are also relatively low when hydrogen is burned, but there are other air pollutants released such as nitrogen oxides, which are precursors to smog, said Mark Jacobson, a professor of environmental engineering at Stanford University.

As for production, green hydrogen generally results in fewer planet-warming emissions than hydrogen produced from fossil fuels. But even that process can be very energy intensive, explained Neumann, with Environment America — much more so than using renewable electricity directly. “We may get more decarbonization bang for the buck in the short run by using renewables for other purposes than to create hydrogen,” she said.

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He’s (Jacobson's) the co-author of the study that found that when the full production process is taken into account, the “greenhouse gas footprint of blue hydrogen is more than 20 percent greater than burning natural gas or coal for heat and some 60 percent greater than burning diesel oil for heat.” That’s in part because the carbon capture equipment itself takes energy to operate.

Jacobson is among those who argue for a relatively limited use of hydrogen, such as in certain industrial processes and long-distance heavy-duty vehicles or aircraft, which are all stubborn areas to decarbonize in other ways.

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The bipartisan infrastructure bill that Congress passed last fall included $9.5 billion for the development of hydrogen. The bulk of that money — $8 billion — is aimed at developing four regional production hubs across the country for clean hydrogen.

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“Blue hydrogen is basically a smokescreen for more air pollution, mining [and] fossil fuel use with hardly any carbon dioxide benefits,” Jacobson said. “We should only use green hydrogen, and it should only be used for certain applications.” READ MORE

The Top 5: The Clean Hydrogen Revolution (Transport Energy Strategies)

Why Are We Still Talking About Hydrogen? (American Energy Society)

Excerpt from American Energy Society: A few pros and cons about hydrogen fuel cells

1. Readily available
2. More efficient than fossil fuels
3. Versatility of use
4. Almost zero emissions
5. Fast charging times

1. Hydrogen extraction
2. Cost of raw materials
3. Infrastructure investment
4. Regulatory issues
5. Highly flammable
Excerpted from What are the pros and cons of hydrogen fuel cells?, by TWI Global

This is an inefficient system that wastes energy. According to a frequently cited study by Transport & Environment, the process of electrolyzing hydrogen already loses 30% of the energy from the process of splitting the H2 from the O. You then have another 26% loss of the remaining energy from transporting the hydrogen to the fuel station, meaning you’ve already lost a total of 48% of the energy before any hydrogen makes it into a vehicle. You can save some of this by making hydrogen on site, but electrolysis plants cost millions, so they will more likely be centralized. In comparison, the typical loss from transferring electricity over wires to a charging station is just 5%, so you still have 95% left.

Things are already looking bad for hydrogen before you even put it in a car, but then you have the inefficiency of the powertrain in the vehicle. There are ways to burn hydrogen directly using synthetic fuel types or even via a paste, but these fuels lose even more energy in the process of production, and potentially have particulate emissions issues too. So, instead, for most personal hydrogen-based transportation applications, a clever technology called a fuel cell is utilized. This recombines the hydrogen and oxygen to produce water, which also generates electricity. It’s an incredible technical achievement, but unfortunately, you lose half the remaining energy in the process. This means you’re now down to 26% of the original electricity. READ MORE