Towards diversifying the sources of green hydrogen

The National Green Hydrogen Mission, which the government released earlier this month, reads more like a grand wish-list than a feasible roadmap towards the goals stated in the mission. The mission is underpinned by an assumption of rapid roll-out of renewable energy (RE) capacity and the provision of RE at a very low cost, both of which seem to be a big ask. On the other hand, the goals are rather ambitious: 5 million tons of green hydrogen production by 2030, with an ambition to go up to 10 mt with exports.

Unspoken but implicitly evident in the mission document is the excessive reliance on electrolysis. Biomass has been briefly mentioned. But other means of green hydrogen production have not even been recognized. They have apparently been swept under the head ‘R&D’.

But this let-us-see-when-it-happens attitude undervalues ​​the importance of diversifying methods of green hydrogen production. The target is tall and scaling it would mean going after it with everything we have. That thought is palpably missing.


For example, there is hardly any mention of microbial means of hydrogen production. Bio-hydrogen is a proven technology that only needs to be perfected for cost-effectiveness. There are different ways of producing bio-hydrogen — such as anaerobic fermentation (aka dark fermentation), photo fermentation and microbial electrolysis. The last one is seen as holding more promise.

Bio-hydrogen may not be very far fetched. You know that when Reliance Industries Ltd is toying with the idea of ​​algal bio-hydrogen production. A 2021 paper by IIT Bombay’s Monash Research Academy notes that it studied a plant in India that processed 12.790 kg/h of micro algae to produce 1.239 kg/h of hydrogen. “The payback period for hydrogen production was 3.78 years with 22 per cent IRR,” the paper says.

Many researchers have noted that the microbial electrolysis cell (MEC) route of green hydrogen production also has potential. It is not clear as to whether MECs would be eligible for the promised financial incentives for the manufacture of electrolysers. An explicit mention of MEC in the document would have been helpful.

Reducing costs of production by increasing the yield seems to be more of an engineering problem, which involves issues like pre-treatment of algal biomass, choice of enzymes and evacuation of hydrogen produced because the presence of hydrogen inhibits further production of the gas. These are not intractable problems.

Another hydrogen production method missing in the Indian narrative is the extraction of underground gas. This ‘white’ hydrogen is globally sought after. Pure hydrogen exists deep underground, like natural gas, waiting to be dug out. This route of hydrogen production is yet to happen in a major way globally, but some companies are working on it. India’s ONGC has dug tens of thousands of wells for exploration and production of hydrocarbons. Ravi, who heads the ONGC Energy Center, says that the center has found hydrogen in some wells, but has not pursued hydrogen production. The Energy Resource Institute (TERI), a private scientific think tank, is also aware of the potential of white hydrogen. White hydrogen, it is believed, would be the cheapest source of green hydrogen, costing much less than a dollar per kg, simply because it is just a question of mining it from the depths. Yet it does not figure in any discussion around green hydrogen.

Loop in nuclear

Finally, the mission is silent on bringing in nuclear options for green hydrogen production. For years, the Bhabha Atomic Research Center (BARC), Mumbai, has been working on Indian High Temperature Reactors and Molten Salt Breeder Reactors, which can produce hydrogen using Thorium, an element abundantly available in India. BARC is also setting up a demonstration Molten Salt Breeder reactor plant at Visakhapatnam. “Nuclear energy assisted hydrogen production, is long-term sustainable and environmentally benign,” says a BARC newsletter.

In sum, there is a critical need to have a diversified basket of technologies for green hydrogen production; a need to take the narrative beyond electrolysis using renewable energy.


Published on January 22, 2023

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