A global gold rush for buried hydrogen is underway — as hype builds over its clean energy potential

A global gold rush is underway for a long-overlooked resource that advocates say could play a significant role in the shift away from fossil fuels.

Geologic hydrogen, sometimes referred to as white, gold or natural hydrogen, refers to hydrogen gas that is found in its natural form beneath Earth's surface. It is thought to be produced by high-temperature reactions between water and iron-ich minerals.

Hydrogen has long been billed as one of many potential energy sources that could play a pivotal role in the energy transition, but most of it is produced using fossil fuels such as coal and natural gas, a process that generates significant greenhouse gas emissions.

Green hydrogen, a process that involves splitting water into hydrogen and oxygen using renewable electricity, is one exception from what's known as the hydrogen color rainbow. However, its development has been held back by soaring costs and a challenging economic environment.

It's within this context that momentum has been building around geologic hydrogen. Exploratory efforts are now underway in countries such as the U.S., Canada, Australia, France, Spain, Colombia, South Korea and others.

Research published earlier this month by Rystad Energy showed that 40 companies were actively searching for geologic hydrogen deposits by the end of last year — up from just 10 in 2020.

The consulting firm, which described the pursuit of geologic hydrogen as a "white gold rush," said the hype stems from hopes that the untapped resource could be a "gamechanger" in the clean energy transition.

"I would say this is something relatively old and new in a way," Minh Khoi Le, head of hydrogen research at Rystad Energy, told CNBC via videoconference. "The first project that found hydrogen was