Considering the greenness of renewable hydrogen production in Australia
Graham Palmer, Roger Dargaville, Changlong Wang, Scott Hamilton, Andrew Hoadley
Abstract
Hydrogen produced via water electrolysis powered by renewable electricity is expected to play a key role in decarbonising hard-to-abate industrial sectors. To ensure the climate integrity of hydrogen supply chains, certification schemes have been developed to verify and standardise the carbon intensity of production pathways. Most leading schemes are built around three core principles—often referred to as the ‘three pillars’—designed to ensure that certified green hydrogen delivers genuine emissions reductions. This study evaluates the effectiveness of these principles using life cycle assessment (LCA) within the context of the Australian National Electricity Market (NEM). Our analysis finds that the time matching principle is effective in reducing scope 2 emissions by aligning hydrogen production with periods of renewable generation. However, compliance requires highly flexible operation and expanded infrastructure, resulting in increased embodied (scope 3) emissions—an important but currently unregulated component of most certification schemes. For the geographic correlation principle, we find it to be counterproductive, as restricting hydrogen production to local renewable supply undermines the balancing benefits of inter-regional electricity flows across the NEM. The third pillar, additionality, was not assessed in this study, as its evaluation lies more appropriately within the domain of policy and market design rather than LCA.