A new study has unearthed a massive reservoir of hydrogen gas beneath a chromium mine in Albania, offering a potential avenue for clean energy amidst the global push for sustainability.

The reservoir beneath the Bulqizë mine is estimated to hold as much as 55,000 tonnes of hydrogen, which could sustain a high flow rate for over two centuries.

The research, led by Laurent Truche, a professor of geochemistry at Grenoble Alpes University in France, revealed that the hydrogen reservoir resides within a portion of Earth's crust and mantle that was once submerged beneath the ocean. This section of ancient oceanic crust, now situated in Albania, was thrust onto land millions of years ago, forming a rocky belt known as an ophiolite.

Truche and his team made the discovery while exploring the Bulqizë mine, located northeast of the capital Tirana. They observed significant quantities of hydrogen gas escaping from the rocks and bubbling through pools of water within the mine, indicating the presence of a substantial hydrogen reservoir.

The study, published in the journal Science, highlights the potential of such reservoirs to serve as a source of carbon-free fuel. However, extracting hydrogen from deep underground poses significant challenges due to the lack of infrastructure and the inherent difficulty of extraction.

"We have seen plenty of hyper alkaline springs hosted in ophiolites worldwide where hydrogen is bubbling out," Truche said in comments emailed to Live Science magazine. "But what we have observed deep in the mine is another dimension."

Despite the promising implications for energy transition, safety concerns arise due to the highly flammable nature of hydrogen. The study notes that the high concentrations of hydrogen within the mine have led to several explosions in recent years, requiring improved safety measures.