Large-scale pumped hydro energy storage (PHES) in Victoria could produce electricity for under $A 200 per kilowatt-hour. This is far cheaper that the Tesla low-cost batteries which can produce electricity for about $US 400 kilowatt-hour, excluding the installation and inverter costs. Victoria could use the coal pits in the Latrobe Valley as the lower ponds for a PHES scheme. Some of these coal pits have been dug to 60 metres below sea level. Existing cooling water ponds or new reservoirs would be used as upper ponds.
When excess electricity is produced, water could be pumped from the lower pond to the higher pond. When extra power was needed the water could be returned to the lower pond through a generator to produce electricity.
The large area of the Latrobe Valley pits and the 130 meter elevation difference between the upper and lower ponds would allow a world-class PHES facility offering greater than 1,000 megawatts.
This could support the continuing expansion of variable renewable wind and solar electricity generation.
Renew Economy: 15 May 2015