Capital and energy considerations for large scale hydrogen export

New Zealand is exploring the possibility of exporting hydrogen produced from its abundant renewable energy resources. A key question that arises is what is the “best” way to transport hydrogen internationally at large scale. There is no simple answer to this question, as the “best” option will depend on the customer and their intended usage, the efficiency and safety of the supply chain and the availability of critical infrastructure. In this paper, we discuss the results of our recent study [1] that explored the capital cost and energy efficiency considerations of the three most prominent potential hydrogen carriers: liquid hydrogen, ammonia and the toluene/methylcyclohexane system (MCH). Capital costs for a nominal power draw of 600 MW were developed for the electrolyser and carrier formation plants, and for the overseas decomposition plant in the case of the MCH option. Despite significant differences in the amount of hydrogen produced, the overall capital envelopes were remarkably consistent (~$2 billion). The contributions of the cost of electricity (at a net cost of $65/MWh) and levelized cost of capital indicated that liquid hydrogen could potentially be the most cost effective solution, although it requires the construction of new shipping vessels. Ammonia for direct use is comparable, and has no infrastructure barriers, but ammonia decomposition and MCH dehydrogenation are energy intensive and result in higher costs. The presentation will develop this study further through the addition of sensitivity analysis. [1] Hinkley et al., IJHE, 47(85), 35959-35975, https://doi.org/10.1016/j.ijhydene.2022.08.192