Green Hydrogen Production: The Backbone of Clean Energy

Somewhere in northern Chile, a pilot plant has been splitting water with solar power and turning it into fuel since the mid-2010s. I remember reading about it years ago on a specialised site and thinking: "Nice demo. It'll never scale." Then I ran the numbers myself on a small electrolysis setup I was curious about, and the reality hit harder than the press release. What I built was a toy. The gap between that toy and an industrial plant is where the entire story of green hydrogen production lives.

So let's talk about what actually works, what doesn't, and where this fits into clean energy. Not the version where hydrogen saves everything by 2030. The version where it does a few jobs very well and a lot of jobs badly.

What actually makes hydrogen "green"?

Hydrogen is not a colour. It is an element. The colour labels are a shorthand for how it was produced, and that shorthand matters more than most marketing suggests.

Grey hydrogen comes from steam methane reforming — you take natural gas, strip the carbon, and vent the CO₂ into the atmosphere. This is how the overwhelming majority of hydrogen is made today, and it has been for decades. Blue hydrogen uses the same process but captures part of that CO₂ and stores it underground. Green hydrogen skips fossil fuel entirely: you run an electric current through water, and the water splits into hydrogen and oxygen. If the electricity came from wind, solar or hydro, the hydrogen is green.

Is green hydrogen renewable energy?

Not exactly, and the distinction matters. Hydrogen is an energy carrier, not a primary energy source. Sunlight and wind are the renewable sources. The hydrogen is a way of moving and storing what they produce. So when someone asks whether green hydrogen is renewable, the honest answer is: it is only as renewable as the electricity that made it. Plug an electrolyser into a coal-heavy grid and the "green" label becomes fiction. This is why the EU and other regulators tie certification to the actual power source, not to the molecule's colour.

I'd go further: a lot of the confusion in public debate comes from treating hydrogen as if it were a fuel like diesel. It isn't. It's a battery you can pipe.

How green hydrogen is made: the electrolysis methods, compared

Electrolysis sounds exotic. It's actually a secondary school experiment — two electrodes in water, bubbles at both ends. Industrial plants do the same thing at scale, with four main technologies fighting for the market.

Alkaline electrolysis is the veteran. Cheap, robust, mature, but slow to start and stop, which matters enormously when your power source is an intermittent wind farm. PEM (proton exchange membrane) responds fast, works at higher current density, and is the favourite for pairing with renewables — but it needs platinum and iridium, both scarce and expensive. SOEC runs hot, above 700°C, achieving higher efficiency when you have waste heat to feed it — steel plants and nuclear sites are the obvious candidates. AEM is the newcomer, promising the best of alkaline and PEM without the precious metals, but it's still mostly in labs and early pilots.

Method	Maturity	Response speed	Main weakness
Alkaline	Commercial, decades of use	Slow	Poor fit for variable renewables
PEM	Commercial, scaling	Fast	Platinum and iridium dependency
SOEC	Pilot to early commercial	Moderate	Needs high-temperature heat
AEM	Lab and early pilot	Fast	Not yet proven at scale

The catch? Whichever method you pick, you're spending more energy to build the hydrogen than you'll ever get back.

The efficiency problem nobody puts on the brochure

Here's the number that reframes everything. Take 100 units of renewable electricity. Run it through an electrolyser and you keep around 70 to 80 of them as chemical energy in the hydrogen. Compress or liquefy it for transport, and you drop further. Convert it back to electricity in a fuel cell, and you keep maybe 40 to 50 of the original 100. The full chain typically loses 60 to 70 percent of the energy you started with.

Compare that to a battery. Charge a lithium-ion pack and discharge it, and you lose only 10 to 15 percent. For a passenger car, that gap is not a rounding error. It is the whole argument.

Which brings up an obvious problem. If the priority is cutting emissions fast with limited clean electricity, why would you deliberately throw away two-thirds of it? You wouldn't — not for anything electricity can already do.

Where green hydrogen genuinely earns its place

It earns its place exactly where electricity can't easily go. Steel production, where hydrogen can replace coking coal as the reducing agent. Ammonia for fertiliser, which today is made almost entirely from fossil gas. Shipping and long-haul aviation, where batteries are too heavy for the range required. Refining, chemicals, and industrial heat above what heat pumps can deliver.

I want to be blunt about the counter-example, because it's where most hype collapses. Home heating with hydrogen? Almost always a losing proposition against a heat pump. Passenger cars? Same story. I've watched two or three well-funded hydrogen car projects quietly fold, and honestly, the physics explained why long before the balance sheets did.

• Strong fit: steel, ammonia, methanol, refining
• Plausible fit: shipping, aviation, long-duration storage, industrial heat
• Weak fit: cars, home heating, short-distance transport
• No fit: anything a direct cable or battery already handles cheaply

Challenges of green hydrogen: cost, water and infrastructure

Cost is the wall everyone hits. Grey hydrogen from natural gas has been cheap for years because the feedstock is cheap and the plant has long been paid off. Green hydrogen costs several times more per kilogram in most markets, because you're paying for electricity, for the electrolyser, and for the fact that the whole industry is still young. The trajectory is downward — electrolyser prices have fallen sharply over the past decade — but the gap hasn't closed yet.

Then there's water. Electrolysis needs pure water, and a lot of it. Siting plants in sunny deserts sounds elegant until you realise you're competing for the same scarce resource as agriculture and drinking supply. Desalination solves it, at an energy cost that eats into your efficiency gains.

Infrastructure is the third wall. Hydrogen is a small molecule. It leaks through seals, embrittles steel pipelines, and needs either compression or liquefaction to move — both of which burn energy. Repurposing existing gas networks is possible in places, but it isn't free and it isn't universal.

What about transport and storage?

Storage is where hydrogen has a genuine edge over batteries. You can hold it in salt caverns, in depleted gas fields, in tanks — for weeks or months, at a scale batteries can't match economically. That's the long-duration storage argument, and it's a real one. The problem is everything around it: moving the molecule from where it's cheap to make to where it's needed is where most of the cost and complexity live.

Where the industry actually stands in 2026

Let's separate announced projects from steel in the ground. Headlines love gigawatt-scale announcements. The reality is that most announced capacity is still at final investment decision stage or earlier, and a fair share never gets built. Electrolyser manufacturing capacity has grown fast, but actual installed and operating capacity is a small fraction of what's been promised on paper.

Europe pushed hard with its hydrogen strategy and a dedicated bank forhydrogen projects. The US offered a production tax credit that, depending on how the rules land, can transform project economics overnight. Gulf states, Chile, Australia and Namibia are all positioning as exporters. China has quietly become the largest manufacturer of electrolysers, which changes the cost curve for everyone.

The honest read: this is a sector in the awkward middle. Past the pilot stage, not yet at the scale where costs collapse. I've seen this pattern before with solar — years of looking expensive, then a tipping point where it stopped being a debate. Hydrogen may follow. It may not. The difference is that solar had a clear cost-down path; hydrogen's is messier because it depends on cheap electricity, cheap electrolysers, and demand that still largely doesn't exist at scale.

Hydrogen in the energy transition: hopes, challenges, realistic opportunities

If you ask me where this lands, here's my position, and I'll defend it. Green hydrogen will play a meaningful but narrow role. It will decarbonise steel, ammonia, and parts of shipping and aviation. It will provide long-duration storage in places with exceptional renewable resources. It will not heat your home, it will not power your car, and it will not replace the grid.

The mistake the industry made — and I say this as someone who watched it happen — was overpromising in the early 2020s. Every sector got a hydrogen pitch, including ones where the physics said no. That overselling created a backlash, and now we're in the correction phase. Projects are being cancelled. Targets are being missed. And honestly, that's healthy.

What survives the correction will be the applications that make sense on efficiency and cost grounds alone, without subsidy. That's the test that matters. Everything else is a PowerPoint.

Is green hydrogen really zero-emission?

At the point of use, yes — burning or reacting hydrogen produces water, not CO₂. But the full lifecycle depends on the electricity source and on how the hydrogen was transported. If the power came from a coal-heavy grid or the molecule leaked heavily in transit, the emissions savings shrink. Zero-emission at the tailpipe is not the same as zero-emission across the chain.

Why is green hydrogen so expensive compared to grey hydrogen?

Three reasons stack up: electricity is the dominant cost and renewables are still more expensive per unit than natural gas in most markets; electrolysers are capital-intensive and the industry is young; and the supporting infrastructure — compression, storage, pipelines — adds cost that grey hydrogen avoids because it's already built into existing fossil infrastructure.

Will green hydrogen replace natural gas?

Partly, in specific industrial uses. Broadly, no. The efficiency losses make it a poor substitute for direct electrification in heating and power generation. Where it will substitute is in processes that need a chemical feedstock or a high-temperature flame, not in the pipes running to your home.

The most useful thing you can do with all the hydrogen hype is ask one question: does the end use actually need a molecule, or would a cable, a battery, or a heat pump do the job better? Where the answer is "it needs a molecule," green hydrogen has a future. Where the answer is anything else, it's a distraction. I keep a running tally of projects I was told would change everything — most of them didn't. The ones that did all passed that one question first. That's the whole lesson, and it took me a lot longer to learn it than I'd like to admit.