The Centennial Pumped Hydro Energy Storage project will perform a series of technical studies and trials for the potential deployment of a nominal 600 MW pumped hydro energy storage (PHES) system using underground coal mining voids.
The Centennial Pumped Hydro Energy Storage project acknowledges that Large-scale PHES can firm up intermittent renewable generation. It provides flexibility and balancing management allowing the market operator to ensure security and reliability given a high (>50%) integration of renewable intermittent generation. AEMO’s Integrated System Plan 2020 suggests the NEM will require 6-19 GW of storage by 2035.
It is estimated that underground coal mining PHES, when compared to traditional PHES, could result in significant cost reductions driven by the lower cost of civil construction works (due to the pre-existing lower reservoir and existing underground shafts) as well as benefiting from being located close to the strong areas of existing transmission infrastructure associated with incumbent coal fired power generators.
Through performing a series of technical studies and trials the project will test the potential deployment of a PHES system using underground coal mining voids. If successful, Centennial Coal will conduct a detailed engineering design and feasibility study which will culminate into a Final Investment Decision (FID) for one of its Lake Macquarie sites. The construction would be a first-of-kind underground PHES deployment.
The project aims to increase skills, capacity and knowledge of renewable energy technologies by improving the understanding of the technical feasibility and risks of underground PHES, including determining whether a coal mining void is viable as a lower reservoir option for PHES facilities; increase the value delivered by renewable energy by indicating the key materials and designs of turbines and maintenance requirements for successful PHES facilities utilising coal mining void as lower reservoirs; and improve the understanding of the commercial advantages that underground PHES may contribute to the reduction in cost of renewable energy.
Reservoirs of water are poised to play a key role storing renewable energy to bolster the grid.