Is Pumped Hydro part of a Just Transition for the Latrobe Valley? (16.5)

Pumped hydro energy storage (PHES) is a simple means of storing large amounts of energy. All that is required are two storage ponds with at least 90m altitude difference. When power is cheap and in low demand water is pumped from the low pond to the high one. When power is dear and in high demand the process is reversed producing hydroelectricity. This process is already used in the Snowy Mountains. 

In an article published online this week Tim Forcey and Roger Dargaville of the Melbourne Energy Institute suggest that the coal pits and storage ponds of the Latrobe Valley are ideal for changing to PHES.

They wrote that “many Australians know that Lake Eyre in central Australia, at 12 metres below sea level, is Australia’s lowest naturally-occurring location. However some of the Victorian brown coal mines have been dug as deep as 60 meters below sea level to form the deepest open-air point in Victoria and possibly on the entire continent. These below-sea-level mine pits would serve as the lower ponds for a PHES scheme. Existing cooling water pondages or new reservoirs would be used as upper ponds… a Latrobe Valley PHES facility would have the competitive advantage of being sited nearly beneath the major electricity transmission lines that supply the Melbourne market.”

The use of already made ponds is a large cost advantage as is the fact that the complete reclamation of the mines would no longer be necessary. This must give the Valley companies some financial incentive for an orderly transition to renewable energy.

They concluded that:  “The real extent of the Latrobe Valley pits (hundreds of hectares) plus the 130 meter elevation difference between the upper and lower ponds allow [for] a world-class PHES facility greater than 1,000 megawatts to be contemplated. Such a PHES facility would, in future, help balance the continuing expansion of variable renewable electricity generation (i.e. wind and solar). Retiring Latrobe Valley brown coal plants and rehabilitating their associated coal pits for a future career in renewable energy storage could be key stepping stones on the path to 100% renewable energy.” The full article can be found here

A detailed study of pumped hydro sites in Australia has been done by the Melbourne Energy Institute and is available here.