S&P Global Platts has released a high-level summary of its analysis of electrolysis-based hydrogen in the short to medium term, finding that the potential to 2028 is relatively small. While the availability of ‘excess’ renewable energy (and the subsequent negative electricity prices that can result) provides a “use case” for polymer electrolyte membrane (PEM) electrolysis, production costs are still not favourable compared to the current dominant means of production, through steam methane reforming or gasification of fossil fuels. It predicts that green hydrogen production will be at only 0.2 million metric tonnes/year this year, rising 150% to 0.5 million metric tonnes/year by 2028. Costs for such hydrogen are expected to be between US$2.50-$3.00/kg (€2.29-2.75) (including capital expenditure), compared to US$1.50-$2.00/kg (€1.37-1.83) for grey hydrogen production (both figures being for California). Part of the reason is that there will not be a great deal of excess renewable electricity available in the medium term, but this would be expected to change as renewables take a greater and greater share of electricity production in the future. Currently, 1 TWh of electricity can produce around 20,000 tonnes of H₂ through PEM electrolysis. Meanwhile, ‘blue’ hydrogen (produced from fossil fuels with carbon capture and storage) is expected to increase production from this year’s 0.5 million metric tonnes/year to 3.5 by 2028, if carbon capture and storage technology allows. Together, then, low/zero-carbon hydrogen production would be at 4 million metric tonnes/year by 2028, compared to the current production of about 76 mmt/y of ‘grey’ hydrogen. That would be seen, perhaps, as a reasonable platform from which to build into the 2030s and 40s.