Wivenhoe: the jewel in Queensland’s crown

It has been described as the jewel in the crown of Queensland’s energy storage system.

And even though it was built 40 years ago, its role is still relevant in the Australian state’s ambitious plan to produce nearly all of its electricity from renewable sources as it gradually shuts down its coal-powered plants.

Located less than 100 kilometres from Brisbane, the state capital, the Wivenhoe Pumped Storage Hydro Power Station was the first of its kind to come into service in the state, and it remains the only one, lending support to the grid by producing electricity whenever wind farms and solar panels are unable to meet demand.

The station was built at the same time as the dam of the same name under a scheme whose aim was also to manage the supply of water to the region and mitigate the risk of flooding. Also part of the scheme was the construction of a second, smaller dam called Split Yard Creek.

Pumped storage means the station acts as a large rechargeable battery, able to generate electricity at a moment’s notice for brief periods of time. Water from the upper Split Yard Creek Dam surges down two tunnels and through the station’s twin turbines, producing electricity before emptying out into the reservoir of the lower Wivenhoe Dam. When demand and electricity rates are low, the water gets pumped back up to Split Yard Creek. The station essentially acts as a closed loop, recycling the water used to produce electricity.

When it came into service in 1984, the station’s technology was leading edge. Controlled remotely from Brisbane, it could be switched on in less than 20 seconds. Its turbines are still among the largest in the world, each weighing 1,500 tonnes with a pumping capacity of more than 200 cubic metres per second. Owned and operated by CleanCo, a power utility owned by the state government, its production capacity has increased from 500 Megawatts (MW) to 570.

“Wivenhoe is the jewel in the crown of Queensland’s publicly-owned energy storage fleet and maintaining it will be critical to achieving our renewable energy target,” read a statement from Mick de Brenni, the state’s minister for energy, renewables and hydrogen in 2021 when he announced maintenance works at the station.

Both the station and the dam were built by a consortium that included Codelfa and Cogefar, a predecessor of Webuild, the Italian civil engineering giant that is overseeing the construction of another pumped storage hydro power station in Australia: Snowy 2.0. Located in the Snowy Mountains in the neighbouring state of New South Wales, it is the largest renewable energy project under development in the country, set to increase the production capacity of the Snowy Scheme’s network of dams and power stations from 4.1 to 6.3 Gigawatts (GW). Webuild is building it with its Australian subsidiary Clough in the Future Generation Joint Venture for integrated energy provider Snowy Hydro Limited. Clough also contributed to the construction of the Wivenhoe power station.

Queensland also plans to build more pumped storage hydro power stations. It sees as crucial the support these stations will provide an expanded power grid called SuperGrid as the state invests tens of billions in solar, wind, battery and hydrogen project. Under the Queensland Energy and Jobs Plan, the government aims to produce 80 percent of its electricity from renewable sources by 2035, up from a current 27 percent. As a consequence, CO2 emissions are expected to tumble by 90 percent.

“Queensland will need at least 6,000 megawatts (MW) of long duration energy storage as part of a diverse future energy system,” says the website of the state’s Department of Energy and Climate. “Clean energy storage, including pumped hydro and large-scale batteries, will be crucial to secure Queensland’s energy system in the long term.”

As work on a pumped storage hydro power station proceeds at an old gold mine, the government is preparing for plans for two more. There is the Borumba Pumped Hydro Project at Lake Borumba west of the Sunshine Coast. Able to store 2 GW, it would be able to power two million homes. Then there is Pioneer-Burdekin project, which would be the largest of its kind in the world with 5 GW of 24-hour storage.