Hydroelectricity: Hydropower in Australia explained

Hydroelectricity is generated when a flow of water – usually from hydroelectric dams – is passed through turbines that can generate electricity. When the water moves through the turbine blades, it causes them to rotate, allowing the generator to convert the motion into electricity (hydropower).

Hydroelectric power generation works in five simple steps:

1. At hydroelectricity power plants (also known as hydropower plants or hydro power stations), water is typically stored in an upper reservoir or hydroelectric dam.
2. Through penstocks, the water is delivered to turbines and released into a lower hydroelectric dam. During this process, water causes the turbine blades to spin.
3. As the turbine spins, they convert the motion into electrical energy.
4. The renewable electricity generated can either be used immediately or stored and used when demand is higher, using Pumped Hydro Energy Storage (PHES).
5. The water is then pumped back into the main reservoir to be used again.¹

Like natural gas, solar power or even nuclear power, hydroelectricity is another energy source that can power homes and businesses across Australia. However, hydroelectricity is a renewable source that is better for the environment than its fossil fuel counterparts.

So, if your home or business uses any amount of electricity, there’s a chance it’s been (at least partially) generated through hydropower.

Hydroelectricity is considered a renewable energy source because it relies on the natural water cycle and gravity to generate electricity. While it does use turbines to convert energy, at its core, no fossil fuels are burnt to produce hydropower.

While hydroelectricity doesn’t generate pollution, hydropower plants and facilities can have negative impacts on the environment. For example, building a new plant may cause damage or destruction to natural ecosystems, change water temperatures and impact wildlife. Similarly, harvesting the materials used to build a plant can produce emissions, which may affect the environment.³

While in some specific cases it’s possible to have a home micro hydropower system, at a minimum, you would need access to a regular flowing water supply (e.g. a river or stream) and be willing to pay high upfront costs for the system. In most cases, hydropower is not a suitable form of energy generation for individual homes.

Instead, you could invest in a solar panel system if you’re looking to use more renewable energy at home or be less reliant on the electricity grid. You can also compare electricity plans as some may offer GreenPower plans, where electricity retailers will purchase accredited renewable energy on your behalf.

Australia is home to multiple hydropower facilities. The biggest is the Snowy Scheme located in New South Wales that’s comprised of eight hydroelectric power stations that have a generation capacity of at least 5 megawatts (MW).⁴

Tasmania has the highest hydroelectricity generation, with approximately 80% of the state’s electricity coming from hydropower.⁵

PHES systems are an important part of hydroelectricity production, as they allow excess electricity to be stored and used when electricity demand is high. They’re similar to solar storage batteries, which allow you to store excess electricity your solar panels produce and use it when it’s most convenient for you.³

While hydroelectricity itself is an important renewable energy source of electricity production, pumped-storage hydropower systems are just as important. They work by allowing electricity to be stored and used when it’s needed most. Here’s how they work:

1. Other renewable energy sources (solar or wind power) pump water from a hydroelectricity dam to an uphill reservoir when demand for electricity is lower.
2. When the demand increases (in peak times or when wind or solar isn’t generating enough electricity), the water is released from the upper reservoir.
3. As water travels to the lower reservoir, it passes through a turbine and electricity is generated.¹

Being a renewable type of clean energy that doesn’t rely on fossil fuels, hydropower provides a multitude of benefits to electricity generation. By utilising hydropower instead of other fuel sources, we can see benefits that include:

• Minimal environmental impacts
• The reduction of greenhouse gas emissions, which can have strong positive impacts on climate change and global warming
• Working in conjunction with other renewable energy types
• Lower maintenance and operation costs.

Like with any form of electricity generation, there are disadvantages that come with developing hydroelectricity facilities:

• Building the infrastructure can be expensive
• Creating a dam may require a lot of concrete, which creates carbon dioxide
• It can cause environmental issues when an area is flooded to create a dam, destroying habitats and impacting local wildlife
• It can be dependent on needing rainfall to continue to be successful
• It takes time to pump water back into the upper reservoir.³