Why the next energy race is for underground hydrogen
I’ve been thinking about underground resources a lot this week, since I’ve been reporting a story about a new startup, Addis Energy. The company is looking to use subsurface rocks, and the conditions down there, to produce another useful chemical: ammonia. In an age of lab-produced breakthroughs, it feels like something of a regression to go digging for resources, but looking underground could help meet energy demand while also addressing climate change.
It’s rare that hydrogen turns up in oil and gas operations, and for decades, the conventional wisdom has been that there aren’t large deposits of the gas underground. Hydrogen molecules are tiny, after all, so even if the gas was forming there, the assumption was that it would just leak out.
However, there have been somewhat accidental discoveries of hydrogen over the decades, in abandoned mines or new well sites. There are reports of wells that spewed colorless gas, or flames that burned gold. And as people have looked more intentionally for hydrogen, they’ve started to find it.
As it turns out, hydrogen tends to build up in very different rocks from those that host oil and gas deposits. While fossil-fuel prospecting tends to focus on softer rocks, like organic-rich shale, hydrogen seems most plentiful in iron-rich rocks like olivine. The gas forms when chemical reactions at elevated temperature and pressure underground pull water apart. (There’s also likely another mechanism that forms hydrogen underground, called radiolysis, where radioactive elements emit radiation that can split water.)
Some research has put the potential amount of hydrogen available at around a trillion tons—plenty to feed our demand for centuries, even if we ramp up use of the gas.
The past few years have seen companies spring up around the world to try to locate and tap these resources. There’s an influx in Australia, especially the southern part of the country, which seems to have conditions that are good for making hydrogen. One startup, Koloma, has raised over $350 million to aid its geologic hydrogen exploration.
There are so many open questions for this industry, including how much hydrogen is actually going to be accessible and economical to extract. It’s not even clear how best to look for the gas today; researchers and companies are borrowing techniques and tools from the oil and gas industry, but there could be better ways.
It’s also unknown how this could affect climate change. Hydrogen itself may not warm the planet, but it can contribute indirectly to global warming by extending the lifetime of other greenhouse gases. It’s also often found with methane, a super-powerful greenhouse gas that could do major harm if it leaks out of operations at a significant level.
