Hydrogen: The Swiss Army Knife of Climate Action?

Thursday - April 25 2024, 12:23 UTC - 6 months ago

Hydrogen, often called the Swiss Army knife of climate action, can be used in a variety of industries but may not be the magic solution for emissions reduction. The Hydrogen Ladder ranks various uses of hydrogen based on factors such as cost and convenience, with existing uses and hard-to-solve sectors ranking highest.

From toaster ovens that work as air fryers to hair dryers that can also curl your hair, single tools that do multiple jobs have an undeniable appeal. In the climate world, hydrogen is perhaps the ultimate multi-tool. It can be used in fuel cells or combustion engines and is sometimes called the Swiss Army knife for cleaning up emissions. I’ve written about efforts to use hydrogen in steelmaking, cars, and aviation, just to name a few. And a new story for our latest print issue explores the potential of hydrogen trains.

Hydrogen might be a million tools in one, but some experts argue that it can’t do it all, and some uses could actually be distractions from real progress on emissions. So let’s dig into where we might see hydrogen used and where it might make the biggest emissions cuts. Most hydrogen is used in oil refining, chemical production, and heavy industry, and it is almost exclusively generated using fossil fuels. In total, hydrogen production and use accounted for around 900 million metric tons of carbon dioxide emissions in 2022.

That’s a central idea behind an infographic I think about a lot: the Hydrogen Ladder, conceptualized and updated frequently by Michael Liebreich, founder of BloombergNEF. In this graphic, he basically ranks just about every use of hydrogen, from "unavoidable" uses at the top to "uncompetitive" ones at the bottom. His metrics include cost, convenience, and economics.

At the top of this ladder are existing uses and industries where there’s no alternative to hydrogen. There, Liebrich agrees with most experts I’ve spoken with about hydrogen. On the next few rungs come sectors where there’s still no dominant technical solution for cleaning up emissions, like shipping, aviation, and steel production. You might recognize these as famously "hard to solve" sectors.

Heavy industry often requires high temperatures, which have historically been expensive to achieve with electricity. Cost and technical challenges have pushed companies to explore using hydrogen in processes like steelmaking. For shipping and aviation, there are strict limitations on the mass and size of the fueling system, and batteries can’t make the cut just yet, leaving hydrogen a potential opening. Cars also rank right at the bottom of the ladder, alongside two- and three-wheeled vehicles, since battery-powered transit is becoming increasingly popular and charging infrastructure is growing. That leaves little room for hydrogen vehicles to make a dent, at least in the near future.

I’m not counting hydrogen out as a fuel for any one use, and there’s plenty of room to disagree on particular uses and their particular rungs. But given that we have a growing number of options in our arsenal to fight climate change, I’m betting that as a general rule, hydrogen will find its niches rather than emerge as the magic multi-tool that saves us all.