This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

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. 

Hydrogen could play a role in cleaning up nearly every sector of the economy—in theory. The reality today is that hydrogen is much more of a climate problem than a solution.

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.

There are technologies on the table to clean up hydrogen production. But global hydrogen demand hit 95 million metric tons in 2022, and only about 0.7% of that was met with low-emissions hydrogen. (For more on various hydrogen sources and why the details matter, check out this newsletter from last year.) 

Transforming the global hydrogen economy won’t be fast or cheap, but it is happening. Annual production of low-emissions hydrogen is on track to hit 38 million metric tons by 2030, according to the International Energy Agency. The pipeline of new projects is growing quickly, but so is hydrogen demand, which could hit 150 million metric tons by the end of the decade. 

Basically every time I report on hydrogen, whether in transportation or energy or industry, experts tell me it’s crucial to be smart about where that low-emissions hydrogen is going. There are, of course, disagreements about what exactly the order of priorities should be, but I’ve seen a few patterns.

First, the focus should probably be on cleaning up production of the hydrogen we’re already using for things like fertilizer. “The main thing is replacing existing uses,” as Geert de Cock, electricity and energy manager at the European Federation for Transport and Environment, put it when I spoke with him earlier this year for a story about hydrogen cars.  

Beyond that, though, hydrogen will probably be most useful in industries where there aren’t other practical options already on the table. 

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. 

Toward the bottom of Liebreich’s ladder are applications where we already have clear decarbonization options available today, making hydrogen a long shot. Take domestic heating, for example. Heat pumps are breaking through in a massive way (we put them on our list of 10 Breakthrough Technologies this year), so hydrogen has some stiff competition there. 

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.

---

Now read the rest of The Spark

Related reading

A fight over hydrogen trains reveals that cleaning up transportation is a political problem as much as it is a technical one. Read more in this story from Benjamin Schneider, featured in our latest magazine issue. 

Where hydrogen comes from matters immensely when it comes to climate impacts. Read more in this newsletter from last year.

Hydrogen is losing the race to cut emissions from cars, and I explored why for a story earlier this year. 

Another thing

It’s here! The Build issue of our print magazine just dropped, and it’s a good one. 

Dive into this story about how artificial snowdrifts could help protect seal pups from climate change. Volunteers in Finland brave freezing temperatures to help create an environment for endangered seals to thrive. 

Or if you’re feeling hungry, I’d recommend this look at how Climax Foods is using machine learning to create vegan cheeses that can stand up to discerning palates. (I have tasted these and can attest that some of them are truly uncanny.) 

Find the full issue here. Happy reading! 

Keeping up with climate  

A solar giant is moving manufacturing to the US. Tariffs and tax incentives are reshaping the solar market, but things could get challenging fast, as my colleague Zeyi Yang reported this week. (MIT Technology Review)

In a new op-ed, Daniele Visioni makes the case that proposals to crack down on geoengineering are misguided. He calls for more research, including outdoor experiments, to make better decisions about climate interventions. (MIT Technology Review)

Americans have some surprising feelings about EVs. And in a recent survey, fewer than half of US adults said they think EVs are better for the climate than gas-powered ones. (Sustainability by numbers)

An Australian supplier of fast charging equipment for EVs is in financial trouble. Tritium told regulators that it’s insolvent, and it’s unclear whether the company will be able to fill orders or service existing chargers. (Canary Media)

Offshore wind has faced its fair share of challenges, but the death of a mega-turbine may have played a major role. GE Vernova canceled plans for a 18-megawatt machine, causing ripples that ended in New York’s move to cancel contracts for three massive projects last week. (E&E News)

The UK’s final coal power station is set to close within the year. Here’s a look at the last site generating what used to be the country’s main source of energy. (The Guardian)

Is it time to retire the term “clean energy”? The term is a convenient way to roll up energy sources that cut emissions, like renewables and nuclear power, but some argue that it glosses over environmental harms. (Inside Climate News)

California saw batteries become the single largest source of power on the grid one evening last week—a major moment for energy storage. (Heatmap News)