We’ve now been covering potential climate solutions on the show for about two years and yet, I must confess, I hadn’t thought much about green hydrogen until President Biden brought it up at the climate summit last week. Biden thinks hydrogen plants could be used in steel and power production and as a zero-emissions alternative fuel. And that it’ll create lots of new jobs.

So, how viable is green hydrogen, actually? Rachel Fakhry is a policy analyst with the Natural Resources Defense Council. She said, first of all, we have to start producing hydrogen in a whole other way. The following is an edited transcript of our conversation.

Rachel Fakhry: So, currently, much of the hydrogen that is used in the in the U.S. — either to produce fertilizer, [or] in agriculture — much of that hydrogen is produced from natural gas, because natural gas contains hydrogen. And the process tends to be very, very polluting. Given the climate crisis, green hydrogen has really emerged as this interesting fuel/molecule that should be developed. So the main difference is that green hydrogen is produced from water. So the process basically involves using renewable electricity, like wind and solar, to split water into its components, extract the hydrogen and use it, producing no emissions or air pollution.

Molly Wood: And do we know how to do that? At scale?

Fakhry: That’s a great question. We know how to do that.

Wood: One down.

Fakhry: Absolutely. This was the main process of producing hydrogen nearly 100 years ago, back when natural gas was still not abundant or cheap. And then natural gas became cheap and abundant, and we switched away from that. So we do have experience doing it. However, green hydrogen is still more expensive than, say, natural gas-based hydrogen. It is, in the U.S., about four to five times more expensive. And that is because the machinery that is used is still expensive. And the process still uses large amounts of renewable energy to produce the hydrogen. That said, experts expect some very large cost reductions in this decade, if we get the right supportive policies in place to get those cost reductions and deploy more and more of it, because the more we deploy of it, the cheaper it gets.

Wood: How would it work and what could it replace?

Fakhry: Some of the highest-value applications include sectors that are very challenging, that don’t have other good established solutions. Those include aviation, maritime shipping, some heavy industry, like for instance, production of iron and steel. Those don’t have good alternatives as of today. And this is where hydrogen could add the most value.

Wood: It seems like there have been efforts at using hydrogen as a fuel in the past, and there is a lot of baggage attached to the word. Because people almost immediately think: “explosion.”

Fakhry: Absolutely. Hindenburg ruined it for hydrogen.

Wood: Seems like it maybe did. We’re gonna need a PR campaign here.

Fakhry: Absolutely, absolutely. Safety should absolutely be a priority for the hydrogen industry. To be fair, you know, since the Hindenburg, industry has developed a very robust set of safety protocols, and has been using hydrogen very safely for many, many decades. However, as we move forward, as I mentioned, and we want to start pushing hydrogen into new applications like aircrafts and shipping vessels, industry needs to absolutely develop new safety protocols for these new applications. And the good news is, and to be fair, industry is really thinking hard about this. And there are big global efforts, looking at this particular question — how do we continue using this safely?

Wood: Is green hydrogen, would you say, the best hope for — particularly when you talk about aviation and shipping, I mean, those are just massively polluting industries. Is there a sense that this is the best fuel alternative for them in the future?

Fakhry: It’s surely one of the leading options. Technology advancement always surprises everyone, but currently, based on today’s landscape, hydrogen, based on its properties as the molecule and the amount of energy it could give, seems to be one of the leading options for aviation, maritime shipping. And what is interesting about hydrogen is the fact that it can be a solution for so many sectors. This sort of sector coupling offers a pretty compelling case, because if you’re using it in ships, and aircrafts, and maybe in some industrial plants, there could be some interesting, you know, cost-sharing mechanisms and risk-sharing across all these industries.

Wood: And then what about the amount of energy that it takes to produce? Is that something that, over time, there are technological innovations that could reduce the amount of energy it takes? Or does it require such a commensurate investment in renewable energy and renewable sources that it becomes kind of a tough trade-off?

Fakhry: This is exactly the reason why hydrogen should not be considered to be the silver bullet solution for all of the economy. It’s precisely this. It needs to be produced first, and it would require some large amounts of renewable energy to produce it. This is why if you can just use your renewable energy directly into electric heat pumps in your home or electric cars, without going through the process of turning it into hydrogen first, this is common sense, that it’s a cheaper, more efficient approach. And this is why the best economic case for hydrogen is in those sectors where direct electrification is challenging, like in aviation and maritime shipping and iron and steel and other challenging sectors.

Wood: What do you think the timeline looks like for deploying this solution broadly?

Fakhry: This is the main question. It is, again, such a new fuel that we don’t really know what the trajectory for scaling it up really looks like. However, experts do project that with the right policy framework, green hydrogen could become cost-competitive with natural gas-based hydrogen by 2030, at which point we could expect that the industry will grow and grow and grow. And over the next eight years, this is the time to put forth the most effective policy mechanisms to support it. And those include tax credits, federal spending, other potential mechanisms that we could make sure that we implement.

Related links: More insight from Molly Wood

The good news is we’re not the only people asking this question. You know, the “What is this and how does it work?” question.

There’s a good piece in the journal Nature about hydrogen and how central it is to the entire idea of carbon reduction. Especially in Europe, which is leading research into producing hydrogen and has actually made it a central plank of almost all its climate policies for the next few decades.

However, the piece notes that some climate scientists are worried that the emphasis on hydrogen could reduce overall investment in other promising solutions, like renewables and direct electrification, especially since some countries see producing hydrogen as a way to actually use their stores of natural gas — which is still ultimately carbon-producing.

It is starting to happen, however. Bloom Energy, based in California, announced this very week that it has deployed its first hydrogen-powered fuel cells, 100 kilowatts worth, in South Korea. They’re currently generating power with zero emissions.