What is hydropower?

22 March 2018

Two fish swim into a concrete wall. One turns to the other and says “dam!”...

It may be a particularly bad joke, but it does have something to do with this post. Hydropower (or hydroenergy) is a form of renewable energy that uses the water stored in dams, as well as flowing in rivers to create electricity in hydropower plants. 

Like other forms of electricity generation, hydropower uses a turbine to help generate electricity; using the energy of falling or flowing water to turn the blades. 

The rotating blades spin a generator that converts the mechanical energy of the spinning turbine into electrical energy. The amount of electricity generated from each power plant depends on the quantity of the flowing water and the height from which it falls. 

Some hydropower plants have what’s known as ‘pumped storage’. This means at night, when demand for electricity is low, water is pumped back up into the dam so it can be released again the next day when electricity demand is higher.

Hydro’s been in Australia for decades

Australia’s biggest hydropower generator is the Snowy Mountains Hydro-electric Scheme, which has a capacity of 3,800 megawatts, almost half of the country's total hydro output. Construction started in 1949 and it was opened in 1972, and spans New South Wales and Victoria. 

With nine power stations, 16 dams and 145 kilometres of tunnels, it’s one of the world’s most complex integrated water and hydro-electricity schemes.1

While the Snowy Mountains Scheme is the largest, there are more than 100 operating hydropower plants Australia. They are typically located in areas with high rainfall and elevation, with the majority in New South Wales, Victoria and Tasmania.

Hydroelectric power provides almost 1/5 of the world’s electricity.2

Hydro in Australia’s electricity mix 

Hydropower generation depends on rainfall patterns and varies from year to year. The wetter it is, the more power that will be generated through hydropower resources.

Typically, hydropower contributes about 8 per cent of the electricity in Australia’s National Electricity Market (NEM) and around 60 per cent of all the renewable energy in the NEM.

diagram elect gen aust nem hydro

Electricity generation in Australia's National Electricity Market3

Read more about other renewable energy sources in Australia.

  1. Snowy Hydro Limited, Snowy Hydro renewable energy, Snowy Hydro Limited.
  2. National Geographic, Hydropower, National Geographic. 
  3. With analysis from Origin Energy, National Electricity Market generation data is based on the State of energy market report 2014, Australian Energy Regulator, p.25-28.


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