What is renewable gas — and what is it not?

§ 01One name, different gases

"Renewable gas" is not a product but a category. It describes any gas made from a renewable source — organic material, or electricity from wind and sun — instead of from fossil natural gas fields. What these gases share is their origin, not their composition. A methane molecule from a digester is chemically the same as methane from Groningen. Which is why you can never tell from the gas itself whether it is renewable, only from the chain behind it. [1]

In practice you'll come across five terms that often get used interchangeably:

• Biogas — raw gas from anaerobic digestion of manure, crop residues, sewage sludge or organic waste. Consists mainly of methane and carbon dioxide, with traces of other substances. Usually used locally, for example in a combined heat and power unit at the digester.
• Biomethane — biogas upgraded to natural gas quality: carbon dioxide and contaminants have been removed, and what remains is almost pure methane. In the Netherlands this is also called green gas, especially when it is injected into the gas grid.
• Bio-LNG and bio-CNG — biomethane that has been liquefied (LNG) or compressed (CNG) so it can be transported without a pipeline. The same molecule, in a different form.
• Renewable hydrogen — hydrogen made with renewable electricity (electrolysis). Under RED III this falls under "renewable fuels of non-biological origin". A different molecule, with its own infrastructure and its own limits. [1]
• Synthetic methane — methane made from renewable hydrogen and captured carbon dioxide. Technically possible, still scarce at scale.

§ 02What it is not

This is where the market often goes wrong. Three things are regularly sold as renewable gas, but are not:

• Offset natural gas. Fossil gas whose emissions are "offset" with certificates from forestry projects or other climate projects. The gas stays fossil; the offset is a separate and often contested claim.

That does not mean certificates are worthless: they are exactly the instrument that records origin administratively. The point is that the certificate and the molecule have to belong together if you want a physical, demonstrable replacement of fossil fuel.

§ 03When may a gas be called renewable?

Not every digester automatically delivers "sustainable" gas. The European Renewable Energy Directive (RED III) sets requirements for the feedstock, for emissions across the whole chain and for the way that is demonstrated. Gases that meet them count towards the national targets and may be reported as renewable. Gases that do not, do not count — whatever the invoice says. [1]

§ 04Why this matters to you

For a client, an accountant or a permitting authority, the distinction is not semantics. A claim like "we run on renewable gas" has to hold up when someone asks further questions: which gas, from which source, through which chain, with which certificate. If you don't know the difference between biogas, biomethane and a standalone certificate, you soon buy a claim that falls apart at the first audit.

Powercrumbs works only with locally available renewable gas whose origin is recorded per batch and that is physically delivered on site — the molecule and the proof together. How that recording works is explained in the article on chain of custody. Or check your own situation in the fossil replacement scan.

§ 05References

• European Union — Directive (EU) 2023/2413 (RED III) — definitions of biogas, biomethane and renewable fuels of non-biological origin; sustainability and greenhouse gas criteria.Legislation · primaryPrimary
• Dutch Emissions Authority (NEa) — Explanation of renewable energy for transport, certification and the role of the Union database for gaseous fuels.Regulator · nlHigh

Full references (titles, dates, links) to follow.

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