Natural hydrogen is emerging as a potentially low-cost, clean energy source, attracting global interest as nations seek sustainable alternatives to fossil fuels.

What is Natural Hydrogen?

• Natural hydrogen, also called “geologic hydrogen,” is a free gas that occurs underground due to natural geological processes like serpentinisation, radiolysis, and organic matter decomposition.

• Formation of Natural Hydrogen: It is formed when water reacts with iron-rich rocks, or when radioactive decay splits water molecules deep underground
  • It can also originate from volcanic outgassing or organic-rich sediments.

Advantages of Using Natural Hydrogen

• Low Carbon Footprint: Natural hydrogen emits minimal carbon when extracted and burned, making it cleaner than grey or blue hydrogen.
  • With proper mitigation, it is even cleaner than blue hydrogen.
• Lower Cost of Production: Natural hydrogen extraction can cost less than $2 per kg, significantly cheaper than green hydrogen, which currently exceeds $6 per kg due to renewable energy costs.
• High Energy Potential: According to the US Geological Survey (USGS), even if only 2% of natural hydrogen reserves are exploitable, they could meet global hydrogen demand for over 200 years.

Reserves and Extraction of Natural Hydrogen

• Accidental Discovery :  In 1987, a flame accidentally triggered during water drilling in Bourakébougou, Mali, led to the discovery of 98% pure natural hydrogen underground, paving the way for renewed exploration.
• Global Discoveries: Hydrogen seeps have been found in over a dozen countries including the U.S., Australia, France, Spain, South Korea, and Canada.
  • France’s Moselle and Lorraine regions hold an estimated 92 million tonnes.
• India’s Potential : India shows promise with geological structures like ophiolite complexes in the Himalayas and Andamans, volcanic-sedimentary belts in cratons (Dharwar, Singhbhum), and active hydrothermal systems in hot spring areas.
• Current Exploration Technologies: Hydrogen-sensing gas probes and spectrometers are now used to detect dissolved hydrogen in rock formations up to 1,500 metres deep, with ongoing development to reach 3,000 metres.
• Industry Momentum: Over 40 companies globally are currently exploring natural hydrogen sites, up from 10 in 2020. Major firms like BP, Rio Tinto, and Amazon’s Climate Fund are investing in the sector.

Potential of Natural Hydrogen as a Clean Energy Source

• Energy Security and Transition Support: Natural hydrogen offers a scalable, cleaner fuel that can complement green hydrogen and aid global decarbonisation goals without the heavy energy input of electrolysis.
• Untapped Market in India: While India has not yet explored natural hydrogen systematically, experts urge government-supported research and exploration to harness potential reserves and align with the country’s green hydrogen ambitions.
• Sustainability: The environmental sustainability of natural hydrogen depends on extraction techniques, associated gas emissions, and managing hydrogen leakage, which is an indirect greenhouse gas.

Conclusion

Natural hydrogen, once a geological curiosity, is now being recognised as a viable and cleaner alternative energy source. With technological advances and increased exploration, it may play a pivotal role in the global clean energy transition, provided that exploration, regulation, and environmental safeguards progress in tandem.