India’s green hydrogen mission is one of the most ambitious clean energy commitments in the world. A target of 5 million metric tonnes annually by 2030, backed by 125 gigawatts of dedicated renewable capacity, places India at the front of a global race to decarbonise hard-to-abate sectors and build a new export industry from the ground up. The scale of that commitment deserves an appropriately rigorous accounting framework to match it.
India currently certifies green hydrogen against a single threshold: 2 kg of CO2 per kg of hydrogen, calculated using the grid’s annual average emission factor (grams CO2 per kWh electricity). This is a strong threshold, and in line with global best practices.
However, the grid does not emit CO2 equally all the time. The grid mix shifts by the hour, with extensive solar supply through the afternoon and coal dominating the evening. Thus, the instantaneous emissions for what an electrolyser draws at 2 pm are very different from what it draws at 8 pm.
This research builds a Levelized Cost of Hydrogen (LCOH) minimisation model (optimizing a mix of renewable energy, storage, and imported grid power) alongside a 2030 grid emission factor estimation. The study optimises green hydrogen production within India’s official norm, the 2 kg-CO2 per kg-H2 annual average limit, and then calculates what actual emissions look like when measured hourly. We find that the gap from annual to hourly is significant.
Even while staying within the annual constraint, hourly attributional accounting reveals emissions roughly 25 percent higher than the official number suggests. Once electricity banking (a form of accounting offsets) is factored in, and the coal-heavy evening supply that typically backs those withdrawals is accounted for, attributional emissions can be double the official threshold and consequential emissions can exceed it by three times or more. In other words, producers can be fully compliant under today’s norms and still be carrying an emissions footprint that India’s trading partners, particularly in Europe where hourly accounting is becoming a legal requirement, will not accept. It is also an emissions footprint that, if not mitigated, erodes the case for green hydrogen as a cost-effective climate solution.
This gap also matters beyond hydrogen. The deeper question the study surfaces is about how India accounts for grid emissions across any large-scale electricity consumer making a decarbonisation claim. Green hydrogen makes the arithmetic unusually clear, because the volumes are large, the international scrutiny is high, and the cost of getting the accounting wrong is visible. But the principle extends further.
The study finds a clear upside. Demand flexibility, running electrolysers during the hours when renewable energy is most abundant and ramping them down when coal is most dominant, reduces both costs and emissions at the same time. The modelling identifies a capacity utilisation sweet spot of around 70 percent where that trade-off is most favourable. Pairing this with right-sized storage and smarter grid interaction produces outcomes that work both economically and environmentally. The levers are available. India should have a trajectory towards more rigorous emissions accounting, which will both help exports and also incentivise greener solutions.
The full report is in progress. To cite this preliminary work:
Vijay, R., Tongia, R., Budden, P., and Katiyar, A. (2026). “Green Hydrogen Pathways in India from a Grid Perspective: How RE mix, banking, grid-imports, and key policy levers influence cost and emissions.” CSEP and NRDC. Preliminary Results, Peer Review in Progress.
