When I heard the sentence “green hydrogen is not always green” a few weeks ago, it made me stop and think. I first encountered hydrogen around fifteen years ago at Daimler AG. Since then, I have repeatedly returned to the topic, and in recent years I have been working with it intensively in both the Czech and European context.

Despite this experience, I must admit that some concepts and connections related to the “greenness” of hydrogen are not intuitive at all. It is often unclear what these terms actually mean—and why certain hydrogen pathways are considered valuable while others are not, even if both can be low-emission or clean.

And I am certainly not alone. Confusion around what is green, renewable, low-carbon, RFNBO or RED-certified hydrogen is widespread across Europe. Although hydrogen is discussed more frequently than ever, many stakeholders struggle to understand why individual technologies fall into different regulatory categories—and what practical consequences this has.

This was the reason why I decided to start writing about this topic: simply, technically, and in an understandable way. For everyone who is dealing with decarbonisation in practice.

Who Is Dealing with Decarbonisation Today? Almost Everyone.

Hydrogen is no longer a niche topic for a small group of technology companies. It affects:

  • energy-intensive industries such as steel, cement, glass and chemicals,

  • logistics companies,

  • cities and regions,

  • the construction sector,

  • aviation and defence,

  • and many other sectors going forward.

Anyone with high emissions is facing the same question: How can fossil hydrogen or natural gas be replaced—and how can European regulatory requirements be met?

And this is where the challenge begins: green hydrogen is not always equally green.

The reason is not technological—but regulatory.

Different Categories of Hydrogen in EU Regulation

The European Commission defines several hydrogen categories that differ significantly from one another.

RFNBO – the “gold standard”

RFNBO (Renewable Fuels of Non-Biological Origin) refers to hydrogen produced via electrolysis using exclusively renewable electricity.

To qualify as RFNBO, strict criteria must be met:

  • additionality of renewable electricity,

  • temporal correlation,

  • geographical correlation,

  • more than 70% greenhouse gas emission savings compared to fossil hydrogen.

As a result, RFNBO is extremely difficult to achieve in countries like the Czech Republic, where stable renewable electricity generation is limited.

RED II / RED III – a different logic

Under RED II and RED III, hydrogen can qualify as renewable if sustainability criteria, emission savings and feedstock origin requirements are fulfilled. Biomass-based pathways are explicitly allowed.

Hydrogen can be produced:

  • thermochemically from residual biomass,

  • from biomethane or biogas,

  • from waste streams that comply with RED sustainability rules.

Alternative low-emission hydrogen technologies

Beyond electrolysis and biomass, several other pathways exist:

  • methane pyrolysis,

  • partial oxidation of biomethane,

  • plasma technologies,

  • reforming with CCS,

  • waste gasification under RED conditions.

These technologies can significantly contribute to decarbonisation, even if they fall into different regulatory categories.

Why Does This Complicate Decarbonisation?

At the HyBaBo conference in Selb (Germany), I heard something that genuinely surprised me:

Companies prefer paying high penalties for missing RFNBO quotas rather than using cheaper, stable hydrogen compliant with RED II/III.

The reason was simple:

“Because it does not count towards the mandatory RFNBO target.”

This, despite the fact that RED-compliant hydrogen can be cheaper, locally produced, available 24/7 and have a very low carbon footprint.

This was a key realisation for me: technological reality and regulatory reality are currently diverging significantly in Europe.

What Is the Aim of This Series?

This series is intended to help those who feel lost in the growing complexity of regulations, acronyms and decarbonisation requirements—just as I once did before I began connecting the dots.

It is not meant to be an academic textbook or a finished guide. Instead, it is a process of exploration, explanation and sharing insights gathered through real projects, discussions and practical experience.

Above all, I want to contribute to ensuring that hydrogen becomes a real tool for decarbonisation—not just a regulatory checkbox.

Kristýna Váchalová
Hydrogen Business Development
✉️ info@hyconnect.eu
🌐 www.hyconnect.eu