Billions of dollars of hydrogen projects by Australian companies including Woodside and Fortescue may be in doubt after the US proposed rule changes that could exclude them from its Inflation Reduction Act cash.

Under Woodside’s plan outlined last year, its H2OK project in Oklahoma would use electricity from the state’s power grid to run electrolysers to produce liquid hydrogen. It would source renewable energy certificates to offset the emissions from the non-renewable power included in that supply.