Gravity and Water Batteries and Everything in Between

Australia’s desire to become four-fifths powered by renewables has created a need for renewable energy alternatives. While solar and wind sources are getting the job done, there is a need to bridge the gap, prevent intermittency, and create energy for overnight storage. And this is where pumped-hydro comes in. 

Pumped hydro basically consists of two strategically positioned dams – one on a hill and another in a valley- connected by pipes and turbines. It works by moving water uphill for storage on sunny as well as windy days and letting the water flow back downhill on serene and cloudy days via a turbine. It turns electricity into gravitational potential energy and vice versa. 

Location is of the utmost importance considering its design. A global atlas that contains greenfield locations for pumped-hydro revealed 600,000 places- these sites have no existent reservoir. Australia is home to approximately 4,000 locations, including the five-gigawatt Pioneer Burdekin-pumped-hydro scheme.  

Luckily, Australia has 1,500 sites in the Bluefield atlas- these are locations with one existing reservoir. With Bluefield locations, another reservoir needs to be built since pumped-hydro requires two. Since there are numerous options, we have the luxury of being choosy; we can fully explore pumped-hydro while selecting only prime locations.

The world’s energy storage is at an all-time low, and the functional ones are virtually all pumped-hydro, together with hydroelectric projects on rivers. 

The exciting part is that this project is possible without new dams on rivers. It is imperative to have a supporting energy source aside from solar and wind, and while Grid-scale batteries are helpful, they only work short-term- minutes to hours. Pumped-hydro, on the other hand, is excellent for overnight and lengthier storage. 

Although Bluefield locations only require one more reservoir, they are not necessarily preferable to Greenfield locations. The reason for this is that these reservoirs are better in areas like the head- the vast difference in altitude that is crucial to energy generation.

Pumped-hydro are also a pro-environment energy source as they don’t necessarily need to be on a river.