Denmark runs on 100% biogas for a day

For one day in early July, Denmark produced enough biogas to meet its entire national gas consumption, a first (BT). Biogas now supplies roughly 40% of Denmark's annual gas use. The record happened because two things moved at once: renewable gas production kept rising while gas demand fell, as fewer Danish homes and factories burn gas for heat. It is a genuine achievement, but a fragile one, built on a country where gas demand is already small and shrinking.

From Manure to Pipeline

The technology is old. Bacteria break down organic waste — manure, food scraps, sewage — without oxygen, producing raw biogas. Clean out the carbon dioxide and impurities and you get biomethane, a gas pure enough to flow through existing pipelines (IEA). Denmark's grid operator, Energinet, uses certificates to track how much renewable gas enters the system. The gas itself mixes physically in the grid; the certificates keep score (Energinet).

This 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 logic is straightforward: gas produced from local waste cannot be cut off by a foreign supplier. And unlike wind or solar electricity, biomethane stores in existing infrastructure and works in sectors where electrification remains slow or expensive, like high-temperature industry or older buildings (European Commission).

The Bill Lands on Remaining Gas Users

The benefits flow to farmers running digesters, project developers, and gas-grid operators. Households gain only indirectly, through greater energy resilience. They can lose directly.

Biomethane production is expensive. Almost everywhere it depends on guaranteed purchase prices, funded through gas tariffs or public budgets. As gas consumption falls, the cost of maintaining pipeline networks gets split among fewer users. France's energy regulator (CRE) raised the regulated gas distribution tariff by 5.87% from 1 July 2026 (CRE). Le Monde described the dynamic plainly: consumption is falling faster than the network is shrinking, so each remaining user pays more to keep the pipes running (Le Monde).

Danish households face the same squeeze. Even with a greening grid, prices still track 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 per year than before the 2022 price shock (Ritzau). Green molecules do not automatically mean cheaper bills.

Germany sharpens the point. A Fraunhofer ISE study found that gas heating 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 useless. It suggests biomethane is too scarce and expensive to keep millions of homes on gas. Its value lies where electrification cannot yet reach: specific industrial processes, backup supply, hard-to-convert buildings.

A Record Built on Favourable Ground

Denmark's milestone reflects decades of farm-biogas investment in a small gas market. Most of Europe is far behind. Ireland targets 5.7 TWh of biomethane by 2030 but has just two grid-injecting plants producing roughly 75 GWh per year, under 1.5% of its goal (We Are Biogas).

The lesson from Denmark is real but conditional. Biomethane works when paired with falling gas demand and discipline about where scarce green gas goes. The risk is that milestones like this become a political argument for preserving gas infrastructure that fewer people will need, while the bill for keeping those pipes open lands on whoever is still connected.