NEW DELHI- A global supply crunch of electrolysers needed to produce green hydrogen and a lack of domestic manufacturers to make them pose a major challenge to India's ambitious targets to use the zero-carbon fuel, a government official told Reuters.

India, which unveiled the first phase of its hydrogen policy on Thursday, plans to manufacture 5 million tonnes of green hydrogen per year by 2030, half of the European Union's 2030 target of 10 million tonnes.

Green hydrogen has the best environmental credentials of the various categories of the clean-burning fuel because it is produced using renewable energy. 

For India, it is critical to its plans to cut carbon emissions, but its green hydrogen target would require at least 10 gigawatts (GW) of electrolyser capacity to split water into hydrogen and oxygen. 

"The kind of electrolyser capacity that will be required to realise all these ambitious programmes, they are not available right now in the country," S. S. V. Ramakumar, a director at the country's top refiner Indian Oil IOC.NS who helped to frame the country's hydrogen policy, told Reuters.

"All the production capacity and order books of big global players are booked and overflowing till 2025," he said.

India will initially import electrolysers, he said adding that state-run refiners planned to form joint ventures with foreign companies manufacturing the equipment.

Power Minister R K Singh said in September India would need at least 10 GW of electrolyser capacity. Global electrolyser capacity was 0.3 GW in 2020, and is expected to reach nearly 17 GW by 2026, an International Energy Agency (IEA) report found in December 2021.

Indian billionaire Mukesh Ambani-owned Reliance Industries RELI.NS has said it plans to build an electrolyser unit in western Gujarat state, but it is unclear when the unit will start commercial production.

India expects initial demand to mainly come from refiners and fertiliser firms, followed by the steel industry and transport. India's refineries are expected to produce 38,000 tonnes of green hydrogen by 2025, Ramakumar said.

(Reporting by Sudarshan Varadhan; editing by Barbara Lewis) ((Sudarshan.Varadhan@thomsonreuters.com; +919810393152; Twitter: https://twitter.com/sudvaradhan @sudvaradhan;))