PLEXOS models, FIRM inputs, data workbooks, and figure data for NEM case study on replacing gas with pumped hydro

Scope: PLEXOS and FIRM models for case study cover the Australian National Electricity Market (NEM). Initial capacity based on 2024 ISP Model developed by the Australian Energy Market Operator (AEMO). Capacity expansion target financial year of 2051-52. Details of study: The 2024 ISP Model developed by AEMO was modified and investigated to identify modelling decisions that bias results towards investing in gas-powered generators. Outdated pumped hydro assumptions, temporal aggregation methods based on typical periods, and a focus on global optimal solutions (rather than near-optimal solution spaces) were found to bias grid configurations towards relying on gas-powered generators to balance solar and wind. Improved pumped hydro assumptions and good quality temporal aggregation techniques were used to find 100% renewable electricity systems in the near-optimal space of the gas-dependent systems. The NEM system was replicated in the FIRM model and modelling to generate alternatives (MGA) was used to generate a large number of near-optimal grid configurations for the 2051-52 target year. Methods: PLEXOS models require a license to the commercial PLEXOS software developed by Energy Exemplar. Annual results from the PLEXOS models are stored in the XLSX files in this datapack and do not require a license to access. The FIRM model is open-source and accessible through the following GitHub link: https://github.com/TimWeberRE100/firm_ce