Fig. 4: Electricity system configuration for least-cost PGP system integration.

The figure illustrates the relative change in electricity costs, grid emissions, and the PGP system’s levelized cost of hydrogen value (LCHV) under varied electricity system conditions. a The best-case (highest positive impact) outcomes, b The most likely (median and central tendency) outcomes, and c The worst-case (least beneficial impact) outcomes are derived from ~30 simulations of the PGP system’s involvement in the electricity system under the minimize cost and emissions scenarios. Relative changes in energy-only cost, reserve cost, and grid emissions are benchmarked against a state without PGP integration, while changes in the PGP system’s LCHV use a baseline with an unchanged grid configuration. Optimal PGP integration in the power sector favours relaxed unit commitment rules that disregard the fossil fuel generators’ minimum generation requirement.