Denmark’s Biogas Day Comes at a Cost

For one day in early July, Denmark did something Europe has been talking about for years: it produced enough biogas to cover all of its national gas consumption, the first time it has managed that (BT). Biogas now accounts for roughly 40% of Denmark's annual gas use.

The achievement came from two movements meeting in the middle. Denmark kept producing more renewable gas, while demand for gas kept falling as fewer homes and factories used it for heat. That makes the milestone real, but also specific to Danish conditions: a country where gas use is already modest and heading down.

From Manure to Pipeline

The technology itself is not new. Organic waste — manure, food scraps, sewage — is broken down by bacteria in the absence of oxygen, producing raw biogas. Once the carbon dioxide and impurities are removed, what remains is biomethane, clean enough to enter the ordinary gas network (IEA).

Denmark's grid operator, Energinet, tracks the process through certificates showing how much renewable gas has been injected into the system. The gas molecules mix together in the pipes; the certificates are the accounting system that says how much of the overall pool is green (Energinet).

That is why the Danish case matters beyond Denmark. After Russia cut gas supplies in 2022, the EU's REPowerEU plan set a target of 35 billion cubic metres of biomethane by 2030 (REPowerEU). The attraction is obvious enough: gas made from local waste cannot be switched off by Moscow.

It also has qualities that wind and solar electricity do not. Biomethane can be stored in existing infrastructure and used in parts of the economy where electrification is still awkward or expensive, including high-temperature industry and older buildings (European Commission).

The Bill Lands on Remaining Gas Users

The winners are clear enough: farmers with digesters, project developers, and gas-grid operators. Households benefit indirectly from a more resilient energy system. They can also be left carrying a very direct cost.

Biomethane is expensive to produce. In most countries it relies on guaranteed purchase prices, paid for through gas tariffs or public money. As fewer people use gas, the cost of maintaining the pipe network is spread across a smaller base.

France shows the mechanism neatly. Its energy regulator, CRE, raised the regulated gas distribution tariff by 5.87% from 1 July 2026 (CRE). Le Monde put the problem plainly: consumption is falling faster than the network is shrinking, so each remaining user pays more to keep the pipes open (Le Monde).

Danish households face the same pressure. Even as the grid gets greener, prices still follow international wholesale gas markets because biomethane enters the same commercial system as fossil gas. One Danish report found households with gas boilers already paying 5,000 kroner more a year than before the 2022 price shock (Ritzau). Green gas does not automatically mean cheaper bills.

Germany makes the point sharper again. A Fraunhofer ISE study found that heating with gas, even with rising shares of green gas, could cost up to €49,000 more over 20 years than a heat pump for a typical detached house (Energie & Management).

That does not make biomethane a dead end. It means it is too scarce and too costly to justify keeping millions of homes on gas. Its real value is likely to be in places electricity cannot yet do the job well: particular industrial processes, backup supply, and buildings that are genuinely hard to convert.

A Record Built on Favourable Ground

Denmark's record rests on decades of farm-biogas investment and a small gas market. Most of Europe is nowhere near that position.

Ireland is a useful comparison. It has a target of 5.7 TWh of biomethane by 2030, but only two grid-injecting plants producing roughly 75 GWh a year, less than 1.5% of the goal (We Are Biogas).

The Danish lesson is valuable, but it is not a shortcut. Biomethane works best when it is paired with falling gas demand and a clear decision about where scarce green gas should go. The danger is that records like this become an argument for preserving gas infrastructure that fewer people will need, while the cost of keeping the system alive falls on whoever is still connected.