South Middleback Ranges Pumped Hydro Prefeasibility Study

As a key stakeholder in the Whyalla region, SIMEC Mining wanted to provide energy security and price relief for their mining and steel manufacturing operations. Approaching the end of its economic life, their Iron Duchess North mine in the South Middleback Ranges had an interesting opportunity. Transform the site into a pumped hydro energy storage facility.

Supported by funding from the South Australian Renewable Technology Fund and the Australian Renewable Energy Agency, we helped deliver a prefeasibility study for the concept using the Iron Duchess North mine pit as the lower storage reservoir of the pumped hydro facility. By constructing the upper reservoir on a platform formed by waste rock spoil in the valley, the team was able to harness a gross head ranging between 150 and 200 metres (490 and 655 feet).

Unlike other pumped storage facilities proposed at decommissioned mine sites or disused quarries, the Iron Duchess North pit was still an operational site. A crucial challenge was integrating the hydropower planning with the mine plan—capturing synergies and maximising benefits to both projects, while achieving the earliest pumped storage commissioning date.

Initial studies were guided by external transmission constraints and the size of the project was limited to 110 megawatts. With the resolution of these constraints, our findings showed a larger 300-megawatt scheme may be a viable option.