Pumped storage |
Middle East: Hatta Dubai Electricity and Water Authority (DEWA) has started trial operations at the 250MW Hatta PSH plant. With a storage capacity of 1,500MWh and a design life of 80 years, the plant represents the first such facility in the Gulf region. Hatta features:
An upper dam with a capacity of 5.3 million m3 A powerhouse 60m underground Two water valves weighing 110 tonnes each
The project is designed to complement Dubai’s large-scale solar PV and concentrated solar power projects, supporting the emirate’s Net-Zero Carbon Emissions Strategy 2050. For engineers, Hatta demonstrates how PSH can be adapted to arid regions with limited hydrological resources, relying on a closed-loop design and careful water management.
North America: Seasonal storage
ambitions In the United States, focus has shifted from daily balancing to long-duration storage. The proposed Carrizo Four Corners PSH project on Navajo Nation land would provide 1,500MW of generation, 1,338MW pumping, and up to 70 hours of storage. Led by New Mexico State University with $14.2 million in funding, the project aims to shift seasonal surpluses of wind and solar into periods of deficit. It would also provide backup for large industrial and data centre loads, stabilising operations during outages or prolonged lulls in renewable production. The Navajo Nation is supporting site access and cultural/environmental reviews, highlighting the importance of community partnerships. For engineers, the project illustrates how PSH design can be pushed beyond diurnal cycles to meet multi-day or even seasonal requirements, opening new frontiers in reservoir sizing, hydraulic head management, and reversible turbine design.
Australasia: mining legacy meets
energy future Australia is investing heavily in PSH as it transitions to renewables. Flagship projects include Snowy 2.0 in New South Wales and the
Kidston and Borumba Pumped Storage Hydro Projects in Queensland. Snowy 2.0, an expansion of the Snowy Mountains Scheme, will add 2,000 MW of capacity and triple the system’s pumping ability. Delivered by Future Generation Joint Venture (led by Webuild and Clough), the project involves tunnelling between the Tantangara and Talbingo reservoirs and a deep underground power station. Three tunnel boring machines – Florence, Lady Eileen Hudson, and Kirsten – are active, while a fourth (TBM Monica) is being prepared for more difficult terrain. Key milestones include excavation of the machine and transformer halls and concrete lining of the Tantangara tunnel. Despite earlier delays, works have resumed and the project is back on track, with first power targeted for late 2027. In September, Voith said it has completed two major Factory Acceptance Tests (FATs) for the project, finalising work on key components in Shanghai, China, and Heidenheim, Germany. In Shanghai, tests were carried out on generator components including the rotor poles for Unit 4 and stator bars for Unit 2. The rotor poles showed uniform magnetic flux density, precise winding, and high-quality lamination. The stator bars met requirements for insulation thickness, partial discharge values, and bar end shaping. The FAT process was conducted under a structured quality framework, which customer representatives described as showing strong manufacturing discipline and effective quality management. At Voith’s Heidenheim site, the Automation
team completed FATs for digital and hydraulic governors for Units 5 and 6. The systems were tested in their final cabinet configuration with live control connections. The FATs marked the first use of bus-controlled proportional valves on an Allen- Bradley PLC platform. After calibration, the system performed as expected. Hydraulic opening and closing times were optimized, and emergency shutdown procedures were successfully tested. More than 30 engineers and technicians
took part in the Heidenheim FATs, using the process to build experience for upcoming commissioning work in Australia.
In Queensland, the Kidston PSH project is transforming an old gold mine into a 250 MW, 2,000 MWh storage facility. Developed by Genex Power, it repurposes two former mine pits and is the first private-sector PSH project in Australia. A dedicated transmission line will link it to the grid, with synchronous generation boosting system stability. The Queensland government and federal agencies are supporting the $777 million project as part of Australia’s National Electricity Market reforms. Construction is progressing, with Unit 2’s spiral case and stay ring installed in April 2025. Energisation is planned for the second half of the year, marking a major step in Australia’s clean energy future. Genex has also signed a 30-year offtake agreement with EnergyAustralia, ensuring bankability and long-term returns for the project. The Borumba project is currently advancing
through detailed design and environmental assessment. Sited at Lake Borumba it will deliver 2,000 MW of generation with 48,000 MWh of storage, supporting continuous output at maximum load for 24 hours. Its design involves a new upper reservoir of approximately 178 GL constructed at elevation, paired with an expanded lower reservoir (Lake Borumba), increasing its capacity from 46 GL to 224 GL and requiring a new dam wall of about 105 metres in height and multiple saddle dams totalling up to 2.3km in length. The gross hydraulic head across the system is planned at roughly 600m. Large-diameter tunnels, an underground powerhouse, and new high- voltage transmission links are key infrastructure components. The scheme’s location, detailed geotechnical investigations, and independent reviews confirm its technical feasibility and its ability to provide grid-scale firming for Queensland’s planned renewable energy penetration targets beyond 70% by 2032
Lessons and outlook The projects advanced in 2025 show a
technology both mature and adaptable: Design innovation: underground caverns (Limberg III), ternary units (Pracomune), and variable-speed machines are extending the operational envelope.
Build speed vs. permitting: China’s accelerated timelines contrast with Europe’s decade-long approvals, showing how governance affects engineering execution. Market integration: Chile and the Philippines illustrate how PSH can be tailored to liberalised versus centrally planned markets. Refurbishment value: modernising legacy plants remains a cost-effective way to maintain system stability. Investment intensity: billion-dollar budgets are now routine, reflecting the scale of underground works and the value of flexibility.
Voith has successfully completed two major Factory Acceptance Tests (FATs) for Snowy 2.0. Image shows the successful integrated FAT for Units 5 and 6 governors at the Heidenheim workshop
26 | October 2025 |
www.waterpowermagazine.com
As 2025 shows, pumped storage is not a relic. It is increasingly the backbone of renewable grids worldwide.
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