What is hydropower?

Chances are you’ve heard the term hydropower used a lot over the last few years. We’re breaking down exactly how this ancient technology works, and how it’ll play a critical role in Australia’s transition to renewable energy sources.

How it works

Humans have harnessed the power of water to drive machines since the dawn of time, with the ancient Greeks first using water-driven mill stones to grind wheat into flour. Hydropower was first used to generate electricity in the late 1880s and now supplies over 16% of the world’s electricity.  

There are three types of hydroelectric power stations; conventional, pump storage and run of river.  Each generate electricity by passing water from a dam (conventional) or river (run of river) through turbine blades to drive a generator to convert the motion into electricity. In the case of pumped storage hydro, water is pumped from a lower elevation dam to a higher one and this water is released to drive the generator when electricity is needed.  

Giant batteries

Typically, pump storage plants will move water between a lower and higher dam during the middle of the day when energy from renewable sources like wind and solar’s plentiful and demand’s low. The water in the higher dam essentially becomes stored energy, much like a giant battery, ready to be released quickly and for long durations to generate energy when it is needed most.    

Like battery storage, pumped hydro will increasingly be used to back up renewable energy sources, stepping in when the sun isn’t shining or the wind’s not blowing.   

The Shoalhaven pump storage scheme

Origin’s Shoalhaven pump storage hydro scheme in the NSW Southern Highlands was first commissioned in 1977. The scheme has hydropower stations at Kangaroo Valley and Bendeela with a total generating capacity of 240MW, while the facility’s dams can also supply water to Sydney during times of drought. 

The scheme was designed to allow for future expansion, so infrastructure needed to grow the station like space for new pipes and transmission lines are already in place. In 2019 Origin completed an assessment that found it was technically feasible to expand the facility by adding one additional generating unit, or approximately 235MW, of new capacity. 

The expansion of Shoalhaven would have the potential to support more renewable energy coming into our National Electricity Market and make it more secure. 

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