The 250MW Kidston pumped storage hydro project (K2-Hydro) is being developed utilizing two existing mining pits in Kidston, Queensland, Australia, approximately 270km north-west of Townsville.

Genex Power is developing the project with an estimated investment of A$330m ($234.6m).

The K2-Hydro project forms part of the Kidston Renewable Energy Hub, which also includes 320MW of solar installations and a 150MW wind farm.

The technical feasibility study (TFS) of the project was completed in November 2016 followed by the completion of the TFS optimization in October 2017.

Early construction works on the project were started in February 2019, while commissioning is anticipated in 2022.

The K2-Hydro project is expected to create 320 construction jobs and estimated to have an operational life of 80 years.

 Kidston pumped storage hydro project location and site details

The pumped storage hydro-electric project is located in the Etheridge Shire Council Local Government Area near the township of Kidston in north-west Queensland.

The project is being developed on the site of the Australia's biggest open-cut gold mine Kidston, which was decommissioned in 2000.

Kidston pumped storage hydropower plant make-up

Kidston will be a closed-loop pumped storage hydroelectric generation facility with an installed capacity of 250MW.

The project will use two existing mining pits at Kidston gold mine, namely Wises and Eldridge. The Wises pit, which covers an area of 52ha, will be used as the upper reservoir, while the 54ha Eldridge pit will be used as the lower reservoir.

The underground powerhouse of the plant will be equipped with two 125MW fixed-speed reversible Francis pump turbines with a start-up time of less than 30 seconds.

During peak electricity demand period, water will be released from the upper reservoir to the underground powerhouse through a concrete-lined pressure tunnel to drive the turbines for power generation. The water from the powerhouse will be further released through a concrete-line tail race tunnel connecting the lower reservoir.

Water during will be pumped back from the lower reservoir to the higher reservoir with the turbines working in pumping mode, during off-peak period.

A 20m-high dam will be constructed around the existing Wises pit and the plant will operate at a maximum gross water head of 218m.

A main inlet valve (MIV) will be placed between the headrace water conveyance shaft and the pump-generator turbines.

A transformer access tunnel will be built parallel to the powerhouse cavern, while a single construction and access tunnel will be constructed from the Eldridge Pit to the powerhouse.

The Kidston pumped storage hydroelectric project will have the capacity for 2GWh of continuous power generation over eight hours in a single generation cycle.

Water supply for the K2-hydro project

Genex Power has the right to draw up to 4.65 billion litters of water a year from the Copperfield Dam located 18km south of the Kidston site. The dam was constructed in the 1980s to serve the Kidston mine. Genex Power also owns the water pipeline connecting the project site with the dam.

Power off-take and transmission

 The power generated from the K2-Hydro project will be directly connected to Australia’s National Electricity Market (NEM) transmission system through a 195km-long and 275kV transmission line connecting the Mount Fox substation.

EnergyAustralia signed a long-term power off-take agreement with Genex Power for the 250MW Kidston pumped storage hydro project in December 2018.

K2-Hydro project financing

Genex Power received a funding of A$9m ($6.4m) from Australian Renewable Energy Agency (ARENA) for the detailed feasibility work of the project.

Contractors involved

 Engineering consulting firm Entura along with HydroChina was involved for preparing the TFS of the project in November 2016.

A joint venture between McConnell Dowell and John Holland was selected as the engineering, procurement and construction (EPC) contractor for the project in October 2017.

 ANDRITZ Hydro is responsible for supply of  turbines for the project, while Powerlink has been awarded the contract to construct the transmission line for the project.

AECOM prepared the initial advice statement for the project in September 2018, while AGE was involved in preparing the groundwater studies.