Mine Gas: In Béthune, an Innovative Project Combining Energy Transition and Social Impact

On March 12, the members of the working group “Urbanization – A Marshall Plan for the City of the Future: Towards a Low-Carbon Urban Model” met to discover a pioneering project developed in Béthune (Pas-de-Calais) by La Française de l’Énergie (FDE), a company specializing in low-carbon energy solutions. In attendance were Pauline Levillain, sustainable finance expert at MAIF, and Shirley Chojnacki, Managing Director, Head of Energy at Edmond de Rothschild Asset Management (EDRAM) and part of the management team of BRIDGE, the group’s infrastructure debt platform.

In 2021, BRIDGE granted its first financing to La Française de l’Énergie through a holding company. “Initially, this funding targeted only cogeneration units located on former coal mining sites in France and Belgium, from which methane naturally escapes. We were very clear: only naturally emitted methane was to be used, with no additional interaction with the subsoil,” Chojnacki explained.

“This methane accumulates in abandoned mines and ends up escaping through decompression chimneys installed by the State during mine closures. When mixed with air, it forms what is known as firedamp. Instead of letting it leak into the atmosphere, we collect it at the surface to prevent emissions and valorize it locally,” explained Julien Moulin, President of La Française de l’Énergie.

For this project, the multi-energy producer conducted no drilling and relied solely on existing infrastructure. “There are about a hundred decompression wells—small chimneys—that can emit gas into the atmosphere when underground pressure exceeds atmospheric pressure,” he added.

Engineering Precision

To effectively collect and valorize the gas, the company relies on a dynamic approach involving fluid mechanics and territorial analysis. The first step is to map the subsurface. “We use both historical data and real-time measurements,” noted Moulin. Most wells are now equipped with sensors that continuously monitor pressure levels. These data feed a reservoir engineering system, where various scenarios are simulated to determine the optimal collection methods and locations depending on the reservoir’s behavior.

The company also monitors water levels in old mining galleries using a network of more than 100 piezometers. “When water rises, it increases pressure and pushes more gas to the surface. So we have to adapt the collection systems,” said Moulin.

This mapping of the subsurface is overlaid with a second layer: that of existing surface infrastructures. The goal is to locate the wells already in place to minimize the land footprint of the project.

A third mapping layer identifies urbanized and protected areas. “Towns were built around the mines. Some areas are off-limits to intervention, and in others, for safety or acceptability reasons, it’s better not to install industrial equipment in the town center,” he said.

This triple mapping—of the subsurface, existing infrastructure, and urban fabric—is complemented by an outlet analysis: “What connects us to the market? Where are the potential consumers? Can we valorize the gas locally?” summarized Moulin. The goal is to ensure that by 2030, no methane will be directly emitted into the atmosphere.

A Real Climate Impact

In a global context where coal is being phased out—especially under investor pressure—transitional solutions must accompany the shutdown of coal-fired plants. “At MAIF, we conducted an engagement campaign in 2023, urging all our asset management partners to adopt a coal exit strategy,” recalled Pauline Levillain. Valorizing mine gas fits into this strategy by offering a concrete, local response to the climate emergency.

Today, this activity already avoids the emission of 3.6 million tonnes of CO₂ equivalent per year. The target is to reach 100 million tonnes by 2030. “We are contributing directly to the collective effort to reduce greenhouse gases,” emphasized Moulin. Methane—the main component of firedamp—has a global warming potential about 80 times greater than CO₂ over 10 years.

Despite this tangible impact, economic valorization remains complex. “We are not currently paid for the CO₂ we avoid emitting. That makes it hard to build a viable business model,” he regretted. However, the work in progress around Scope 4 emissions—avoided emissions—in climate reporting standards could help better recognize this type of solution, especially for investors.

A Supportive but Uneven Regulatory Framework Across Europe

This project in Béthune was made possible by a solid legal and institutional framework. The company holds exclusive concessions across the coal basins of the Hauts-de-France, granted by the French State for 25 years, renewable without competition—offering the long-term stability necessary for such projects.

A decree from November 2016 also introduced a support mechanism for valorizing firedamp, notably through electricity purchase contracts. This fits into a long-term effort that includes mapping, securing, and managing former mining sites. “This groundwork has been particularly well executed in France,” observed Moulin, in contrast to other European countries.

In Poland, for instance, the legal framework remains a significant barrier: the mining permit for firedamp capture is not yet separate from permits for active coal extraction, which hinders coal exit strategies—a top priority for meeting the EU’s decarbonization goals. In many cases, legacy operators (former national coal companies) are no longer operational or cannot handle the environmental liabilities left behind. “In France, the State has clearly separated these historical liabilities from new projects. This gives us very strong legal security,” he explained.

Regulation is thus a crucial lever—but also a barrier—to enabling a successful coal transition. The Just Transition Mechanism aims to help EU countries harmonize their practices, drawing inspiration from French and German models. “We hope that when Poland, Romania, or Greece close their mines, they integrate firedamp valorization directly into their plans, in an intelligent and sustainable way. This would reduce pollution, preserve jobs, produce competitive energy, and support economic regeneration,” he concluded.

A Strong Social Component

From the start, the Béthune project had to meet multiple specifications: fully decarbonize the heat network, use energy sourced within a 100 km radius, extend the network to surrounding municipalities, and contractually guarantee a stable price over 22 years. “The goal was not just to supply energy, but to provide affordable energy. We made strong commitments and asked Dalkia, who was awarded the heat network concession, not to add margins on our energy. This allowed us to pass the savings directly to residents,” explained Moulin.

He believes this social impact is what ultimately aligned stakeholders in a region where a significant portion of the population experiences energy poverty. In Northern France’s former mining basin, where homes are often poorly insulated, this poses real challenges for heating. “It was likely this social component, even more than the energy aspect, that motivated public and regulatory actors to act quickly,” he said.

The permits were issued rapidly. The project went live on January 1, 2021, with the heat network extended to nearly 7,000 housing units and about a dozen public buildings, cutting annual heating bills by nearly €400 per household.

“We were very impressed by the social aspect of the Béthune project: it provides more sustainable heat to residents while significantly lowering their bills,” shared Shirley Chojnacki.

A Robust and Profitable Business Model

While Dalkia extended the heat network, La Française de l’Énergie had to make major investments to rehabilitate the gas capture site, restore part of an existing pipeline, and build a 7 km pipeline to bring the captured gas to the town center.

Installing cogeneration units in downtown Béthune also posed significant technical challenges—especially due to space, safety, and noise constraints in this dense urban environment.

In total, the investments amounted to €9.5 million, including €5 million for the pipeline and €3 million for cogeneration equipment to transform the gas into heat and electricity.

These investments were partially offset by a state-guaranteed electricity purchase tariff, through EDF. “In France, public support takes the form of a feed-in tariff, which ensures a large share of project profitability. It allows us to offer heat at very low prices in Béthune and, most importantly, to commit to the municipality on a fixed rate for 22 years, regardless of how the gas market evolves,” said Moulin.

But the business model isn’t solely based on public support. “When we negotiated the heat purchase contract with Dalkia, we made sure they weren’t adding a margin to our supply. That means the energy savings go directly to the end user. And since we have exclusive access to the resource, and a stable, long-term off-take contract, it’s a reliable and profitable model,” he concluded.