Can Global Shipping Go Zero Carbon? : Short Wave A lot of the stuff we buy in the U.S. comes by ship — ships that use a particularly dirty kind of fuel. Now a big shipping company says it wants to go zero carbon. Climate reporter Becky Hersher tells us how some old tech might play a role and where that tech falls short. Follow Maddie on Twitter @maddie_sofia. Email the show at

Can Global Shipping Go Zero Carbon?

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You're listening to SHORT WAVE...


SOFIA: ...From NPR.

Becky Hersher, climate reporter, you told me this thing that blew my mind earlier - that if all the ships that carry our stuff around the world were a country, that that country would be the sixth-largest polluter in the world.

REBECCA HERSHER, BYLINE: Yeah, right after the nation of Japan, because here's the thing. There are thousands of huge ships, and they carry, like, 90% of what you buy here in the U.S.


HERSHER: Yeah. And they burn this extremely dirty fuel. It's called heavy fuel oil. Sometimes it's called bunker fuel.

SOFIA: That doesn't sound great.

HERSHER: Yeah. And, listen, I cover a lot of, like, big, pollution-heavy industries as a climate reporter. And shipping has something going for it that's kind of cool, which is that they have publicly acknowledged that they have a problem.

SOFIA: (Laughter).

HERSHER: They're dirty (laughter).

SOFIA: That's the first step.


SOFIA: Hi, I'm shipping. I have a problem (laughter).

HERSHER: And I have a problem, and it is greenhouse gases. And second, they're actually trying to change it, which is good. So international regulators are already cracking down. And...


HERSHER: ...This is kind of wild - Maersk, the largest shipping company in the world, has already promised to go zero carbon by 2050.

SOFIA: Zero.

HERSHER: Zero - no emissions from any of their ships.


SOFIA: So today in the show, can the shipping industry really clean up their act and go zero carbon? One solution could be technology that's been around for decades.


SOFIA: OK, Rebecca. It might surprise you that I have not been on a giant shipping vessel before. What are they like?

HERSHER: Yeah. I don't boat either, Maddie...

SOFIA: (Laughter).

HERSHER: ...Or ship, usually.



HERSHER: So I went with a couple of colleagues to visit this cargo ship in Baltimore...

UNIDENTIFIED JOURNALIST: Anything under us there?

HERSHER: ...So something that was representative of the industry. Let me tell you...

UNIDENTIFIED JOURNALIST: Oh, dang. That's steep.

HERSHER: ...Extremely large. It's like a cliff rising above you as you drive up to it.



HERSHER: Rebecca. Nice to meet you.

BUZLOV: Alex (ph).

HERSHER: They were very welcoming. The ship's chief engineer, Aleksei Buzlov (ph), gave us a tour of the ship's engine room.

BUZLOV: So let's go down.

SOFIA: OK. What does an engine room look like? Because I'm picturing, like, old-timey men shoveling coal into a fire. It's very Titanic-y (ph).

HERSHER: Well, there were old-timey men.

SOFIA: (Laughter).

HERSHER: But other than that, it's completely different. So it has, like, a huge engine the size of multiple city buses.

Wow. OK.

But what I most noticed was the smell.

It smells like oil (laughter).

BUZLOV: Smells?

HERSHER: Smells.

BUZLOV: This is gas oil - not smelling more.

HERSHER: Yeah? Oh, yeah. That smells like gasoline. Yeah.

BUZLOV: This gas oil.


BUZLOV: It's more fuel oil, more operated, you know?

HERSHER: More fuel - yeah.

Yeah. So what Aleksei is correctly pointing out is that it smells even worse in there than if they were burning gasoline because they're burning this heavy fuel oil. And there are, like, rows and rows and rows of tanks of it. And fuel oil is really thick and dark. It's like the stuff you put in your car, but, like, on steroids.

SOFIA: Gross.

HERSHER: And it covers everything it touches - like, all the parts of the engine - in this thick gunk.


HERSHER: And there's so much of it that Aleksei, he spends a lot of his day, like, cleaning components. And he collects all that gunk in 55-gallon drums...


HERSHER: ...Of what he calls slop.

SOFIA: Oh, slop is never good.

HERSHER: Yeah. (Laughter) It's very gross.

SOFIA: So why are we using this stuff?

HERSHER: Well, it's dirty, but it gets the job done - packs a lot of energy into a relatively small volume. And it's really cheap to buy right now.

SOFIA: Is there a cleaner fuel that could provide the same kind of energy?

HERSHER: Sure - or maybe. Some people point to liquefied natural gas. That's cleaner than heavy fuel oil, although it's still a fossil fuel, so you're going to get some greenhouse gas emissions. Another option could be hydrogen.

SOFIA: OK, hydrogen. I've heard of it.

HERSHER: The most common element in our universe, so...

SOFIA: Allegedly. Go on.

HERSHER: Allegedly. Yeah. You can use it to make electricity without generating any greenhouse gas emissions at all - no soot, no sulfur, no CO2.

SOFIA: No slop.

HERSHER: All that gross stuff, none of it. And the technology to do that's been around for decades - called the hydrogen fuel cell. It's so old that, at this point, it's really safe. We have good regulations to keep the hydrogen safe. What's new and still unproven is this idea of putting fuel cells onto ships. And to work out the specifics of how to do that, there's actually a group that's building a ship.

SOFIA: We're going to another ship, huh?

HERSHER: Yeah, we are.

SOFIA: (Laughter).

HERSHER: We're leaving Baltimore. We're going across the country. We're going to Oakland. I visited this shipyard where there's a ferry under construction that's actually going to be powered by hydrogen fuel cells, so no carbon.

Sounds a little like "Jurassic Park" in here.


HERSHER: It's actually going to be the first Coast Guard-certified, hydrogen-powered vessel ever in the U.S., which is pretty cool.

SOFIA: Pretty cool. So what does this hydrogen-powered boat look like?

HERSHER: Well, when I went to see it earlier this year, it was just an aluminum frame.


HERSHER: But that's because it was still in a relatively early phase of construction. It will look like a ship. And in the meantime, I got the founder of the company, Joe Pratt, to show me around and sort of point out where everything was going to be.

JOE PRATT: This is the floor. This is kind of where everybody sits. And then it's everything down from that.

HERSHER: So up on the deck when it's done, that's where the hydrogen and the fuel cells are going to go.

SOFIA: OK. So let's walk through the science of how a hydrogen fuel cell actually works.

HERSHER: OK. So it's nothing like the combustion engine that you're used to in, like, your car. In those, you burn fuel - you combust it - to create energy.

SOFIA: Boom.

HERSHER: And so what comes out is gross.

SOFIA: (Laughter).

HERSHER: The - it's pollution. It - right? It has, like, soot and all sorts of stuff that is not very nice in it.

SOFIA: Right. And a fuel cell just converts hydrogen or another fuel directly into electricity through a different reaction, so no combustion, no burning, no boom.

HERSHER: Exactly, no boom. That's, like, the tagline for fuel cells.

SOFIA: Yeah.

HERSHER: But seriously, it's, like, super simple. You're just combining oxygen with hydrogen and creating electricity. You can use that electricity to turn a propeller, in this case, and you don't get all that nasty stuff.

SOFIA: Right. So instead of, like, a sooty, gross exhaust, the fuel cell just gives off water and heat.

HERSHER: Exactly. So instead of, like, carbon and gross exhaust coming out of your tailpipe, you just have this clean, moist air.

PRATT: And we can condense the water that the fuel cells produce. As it goes out the exhaust pipe, the exhaust cools down, and the water falls out of it. It's like raining. And we collect that water, and we'll use it for onboard drinking water.

SOFIA: They're using the water from the exhaust as drinking water.


SOFIA: (Laughter) Mm, give me that sweet, sweet exhaust water.

HERSHER: Yeah, sounds delicious, right? It's actually too clean.

SOFIA: What does that mean?

HERSHER: You ever had distilled water?

SOFIA: Sure, yeah.

HERSHER: It tastes kind of weird?

SOFIA: Yeah.

HERSHER: This is so clean that they'll have to add minerals back into it so it doesn't taste weird.

SOFIA: (Laughter) OK, so this is my question. If hydrogen is so easy, like, what's it - why haven't we been doing this already?

HERSHER: Well, for one thing, fossil fuels have been really inexpensive for a really long time, really ubiquitous.

SOFIA: Right.

HERSHER: They're just easy to get, don't have to pay a lot. Also hydrogen can be difficult to store.


HERSHER: So there's a barrier to entry there. And compared to heavy fuel oil - and I really like this point - it's so interesting, you don't think about it a lot - shipping hydrogen, like, getting it to where you need it to be able to fuel things, it's expensive. And we don't have great infrastructure for distributing hydrogen across the country. So obviously, building all that would cost money and would take time.

SOFIA: OK. What else?

HERSHER: Well, fuel oil is dirty, but it has a major upside, which is that it can pack a lot of energy into every drop.

SOFIA: It's got a lot of oomph.

HERSHER: Exactly, tons of oomph in a very small space. With hydrogen, you get less bang for your buck. You need more of it to get the same amount of power. And that's a problem because you're on a boat, remember? So you don't have unlimited space. So for a really long time, engineers had just assumed that you'd need to get so much hydrogen to power a ship it wouldn't work. It wouldn't fit.

But then, Joe Pratt and his team, what they did, what they're building on here, is this analysis where they found that, actually, it probably is possible to get enough hydrogen onto a ship to power it, at least for some types of ships, some designs. So that's what they're testing here.

SOFIA: Right.

HERSHER: They have this design. They're going to build a ferry, see if they can prove it works.

SOFIA: Gotcha. OK. So I got to ask, like, from a carbon-cutting perspective, there would definitely be some carbon costs to building all these new ships that would use these fuel cells or to, like, retrofit the old ones, right?

HERSHER: Yeah, totally. Retrofitting, building new ships, it would cost a lot of money, emit a lot of carbon. But hydrogen right now, most of it that's produced in the U.S. is actually produced using natural gas.


HERSHER: So it's not completely clean, right? I'm putting clean in scare quotes.

SOFIA: So even though when you're actually using the fuel cells, they don't emit carbon, to get that hydrogen, there is a carbon footprint.

HERSHER: Exactly. And then when we go back to the sort of building, the cost of building new technology, this is an example of something that we see across the economy, right? When you want to transition your economy from the systems that were more polluting to systems that are less polluting, you're in a bind because you have to use the old technology to build the new technology.

SOFIA: Right.

HERSHER: So this is just something that comes with the territory. And there's a question about, well, how cleanly can you build the new, clean technology.

SOFIA: All right. And regardless of that, like, are we really going to be able to scale this up to a point where it would make a big difference?

HERSHER: I mean, listen, I'm not going to sit here and guarantee the entire global shipping industry is going to, like, change over to a new fuel tomorrow.

SOFIA: That's what I thought we were doing here.

HERSHER: Oh, wait; sorry.

SOFIA: (Laughter).

HERSHER: I am going to guarantee that. No, I mean, here's the thing. We're talking about global warming, right? Emitting greenhouse gases, all that pollution, it's creating problems for the shipping industry. There's an incentive for them to scale this back because - imagine you run a global shipping company. Hurricanes are getting more severe, just to choose one effect of global warming.

SOFIA: Right. Not great for ships.

HERSHER: Bad for business. So there's already a financial incentive to switch over to something, and hydrogen appears to be one good bet.

SOFIA: Right. That's why the largest shipping company in the world has made this zero-emission promise. But will one company really make that big of a difference?

HERSHER: Yeah, I think it will. And the analysts I talked to you think it will too because there just aren't that many big shipping companies in the world. So when one really big company like Maersk makes this kind of promise, if they follow through, it could make a really big dent.


HERSHER: One way to think about it would be like if all of the car manufacturers in North America all of a sudden banded together and were like, we're only manufacturing electric cars from now on.


HERSHER: Right? So that's, like, a pretty big deal. And it seems possible that if this new ferry and other prototypes can prove that this is possible, the way they'll do it is using hydrogen.


SOFIA: This episode was produced by Rebecca Ramirez and edited by Viet Le. You're listening to NPR's SHORT WAVE. We'll see you tomorrow.


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