Cleaning Up Coal's Carbon Legacy

Abandoned mines leak methane for decades, but the gas can be captured to provide energy

-  Paul Tullis

Tailings at Avion left over from decades of coal mining

Just outside the northern French town of Avion, there's a 20-foot-wide concrete disk with a small plaque reading "Shaft 7B 19201986." The site marks the entrance to a coal mine that once employed 3,000 people, whose modest red-brick homes still stand nearby. These days, few signs of their work remain other than the 50-foot-high piles of tailings from the mine and a pair of 12-inchwide pipes protruding from the disk that connect to a tangle of tubes and valves.

The pipes carry methane, an odorless, flammable gas that gets released when the coal is dug out of the earth. The methane-the main component in natural gas-rises from 4,000 feet below and accumulates beneath the concrete plug, where a company called Française de l'Energie (FDE) captures it to produce heat and electricity. "You don't need any underground installation," says Julian Moulin, the company's founder, touring the site in a reflective orange puffer over his blue blazer. "You just safely seal the former wellhead, connect it to the pipeline, filter the gas, and inject it into the network."

At the height of the mining era, 350 coal mines dotted northern France and southern Belgium. When cheaper coal became available from abroad and French energy policy shifted to nuclear, they began to shut down. None operate today, but "closed mines produce methane for decades," creating dangerous buildup, says Raymond Pilcher, chair of a United Nations panel on the gas. Because methane has 25 times the global warming potency of carbon dioxide, it's a climate change nightmare. "Coal extraction is forbidden in France now, but we still have this gas issue," says Yann Fouant, FDE's director of operations.