Energy management and climate change

Preparing for the future

We're preparing for an energy-efficient future by finding new ways to keep energy use, emissions and costs down – despite an increasing population and demands for more services. We want Greater Sydney to be a great place to live now and in the future. We'll continue to research and invest in energy efficiency and renewable energy.

Energy use

We make the best use of energy to reduce our operating costs and energy intensity. We use the same amount of electricity each year that it takes to power over 72,000 homes. Treating and pumping water to homes and businesses each day uses a lot of energy. Pumping wastewater away from homes and businesses and treating it uses even more.

Why do we have energy programs?

We recognise that:

  • energy is a valuable resource
  • greenhouse gas emissions from coal-fired power stations are a global environmental issue.

That’s why we're working hard to reduce our energy use by improving our energy efficiency and generating our own renewable electricity. Our programs aim to reduce our electricity use and cost.

How do our programs work?

We focus on:

  • being smart and making the best use of energy
  • investing in energy efficiency improvements
  • recovering energy from wastewater and other waste products, such as food waste
  • generating renewable energy from solar and hydro sources
  • looking for other innovative and cost-effective ways to generate renewable energy.

By doing this, we can minimise the pressures of population growth and the impact of increasing energy prices on our operations.

How do we manage our carbon emissions?

We've set a target for net zero carbon emissions for ourselves by 2030, and for our supply chain by 2040.

Most electricity in NSW comes from burning coal. Buying electricity from the grid adds to our indirect greenhouse gas emissions and our carbon footprint. Indirect carbon emissions can be caused by using or purchasing a product like electricity or other supply chain goods.

We have kept our non-renewable (grid) electricity purchases at or below 1998 levels, even though we are:

  • servicing a growing population
  • providing a more secure water supply
  • providing higher treatment standards.

Cost of Carbon Abatement Tool

We want to make sure that every dollar we invest in carbon reduction is cost-effective for our customers. To help us, we developed the Cost of Carbon Abatement Tool.

We use the tool to:

  • compare projects based on their carbon reduction potential and the marginal cost of carbon abatement
  • progress the projects that deliver carbon and financial savings that are greater than the cost to deliver the project
  • optimise a program of work that delivers the greatest value to customers.

Energy efficiency

How are we managing energy efficiency?

We're reducing energy use by improving the energy efficiency of our processes. Since our program started, we've completed over 46 energy-efficiency projects.

We're now saving almost 13 gigawatt hours (GWh) of electricity each year. That's the equivalent of the power used by over 2,200 homes in a year.

Some of our projects include:

  • using smarter mixing techniques at water resource recovery facilities
  • minimising power use by aerators at water resource recovery facilities
  • installing more efficient pumps
  • investing in energy-efficient buildings. 

Both our Parramatta head office and Potts Hill buildings have 5-star NABERS ratings. They also have 5-star Green Star ratings from the Green Building Council of Australia.

How are we planning for the future?

We'll continue to look for cost-effective ways to reduce our energy use, including:

  • measuring our use and comparing it with industry best practice
  • assessing new technologies and improvements in the equipment we use.

Renewable energy

We generate about 20% of our energy needs from our own renewable sources. That's enough to power over 15,000 homes each year. Renewable energy comes from natural resources that never run out. We're a leader in integrating renewable energy generation into our operations.

Here's how we do it.

Generating electricity from wastewater

Through a process known as cogeneration, we turn waste methane gas (biogas) into electricity and heat. This helps power our water resource recovery facilities.

Biogas is a waste product naturally created during wastewater treatment. Bacteria break down wastewater sludge in anaerobic (without oxygen or air) digesters.

We capture this biogas and convert it into electricity using a gas engine that simultaneously produces power for the water resource recovery facility and heat. We reuse much of this waste heat to maintain the temperatures in our wastewater sludge (solid material settled out during wastewater treatment) digesters, keeping the reaction going to make more biogas.

Producing electricity using the power of water.

We have cogeneration units at 8 water resource recovery facilities: Bondi, Cronulla, Glenfield, Liverpool, Malabar, North Head, Warriewood and Wollongong.

Wastewater gas-to-grid

In partnership with Jemena and the Australian Renewable Energy Agency (ARENA), through a grant, we have started the first wastewater gas-to-grid trial at Malabar Water Resource Recovery Facility. Biomethane is a renewable source of gas. The project can remove 5,000–6,000 tonnes of carbon emissions.

We harness the power of water to produce electricity.

Producing water power 

We have 3 hydroelectric (water power) generation plants, which include a hydroelectric generator at North Head Water Resource Recovery Facility. 

Treated wastewater passes down a large drop shaft on its way to a deep ocean outfall. A hydroelectric generator then captures the energy.

We also produce hydroelectricity from the water supply pipelines from Woronora Dam and from Warragamba Dam to Prospect Reservoir. These hydro power plants use pressure reduction and gravity flow in water and wastewater streams to generate energy.

Using solar photovoltaic and solar hot water (solar power)

We've installed:

  • a 30-kW photovoltaic (solar pv) array on our computer data centre
  • a 60-kW solar electric system on the roof of our Potts Hill office building to provide power to the offices
  • 70 kW of solar power across a number of sites
  • solar hot water systems in many of our depots and water resource recovery facilities. 

We'll continue to invest in solar power to help us reach our net zero target.

Turning food waste into energy (co-digestion)

We've investigated how to use trucked food waste streams to increase the amount of energy generated at our water resource recovery facilities.

This innovation could:

  • reduce operating costs
  • reduce carbon emissions caused by putting this waste into landfill
  • turn more waste into renewable energy – reducing both the waste stream and impacts on the environment.

The waste streams we've investigated include:

  • glycerol, which is a by-product of biodiesel manufacturing
  • commercial and household food waste
  • beverage and dairy waste
  • fats, oils and grease.

In 2014, we ran a 12-month glycerol trial at Bondi Water Resource Recovery Facility. This program proved that a facility could receive trucked organic waste and convert it to energy for its own use. The program helped Bondi become our first water resource recovery facility to generate more electricity than it required to run all its operations.

Following the Bondi facility's success, we introduced co-digestion at our Cronulla Water Resource Recovery Facility – taking pulped fruit and vegetable waste generated from commercial premises in the local Cronulla area. It's expected that this material will increase gas production and allow the facility to generate over 60% of its own electricity.

Our next water resource recovery facility to receive food waste will be Liverpool. We were awarded a grant from NSW Government for the co-digestion project. The co-digestion of food waste will increase biogas production and self-generation of energy on the site. This will contribute to reducing carbon emissions in the future.

Looking forward

We see our water resource recovery facilities as potential clean energy generators of the future.

It's possible that some facilities will generate more energy than they use. They will do this by:

  • using leading-edge, energy-efficient processes
  • maximising the energy capture from wastewater
  • adding new organic waste streams.

In the meantime, we'll continue to:

  • maximise the performance of our renewable energy portfolio
  • install cost-effective renewable energy systems like solar panels within our operations to reduce our reliance on grid electricity. 

The desalination plant operations continue to be fully offset by renewable wind energy.

Getting ready for a changing climate

We provide sustainable water, wastewater, recycled water and some stormwater services to over 5 million people in Sydney, the Blue Mountains and the Illawarra.

Climate change poses potential risks and opportunities for us. This is due to changes in the frequency, distribution, intensity and duration of climate-related events.

Potential risks for us include:

  • reduced fresh water supplies
  • increased customer demand for water
  • increased risk of severe bushfires in water catchments
  • increased algal blooms in dams
  • increased risk of pipe corrosion and odours
  • more extreme storms that push our water resource recovery facilities over capacity
  • higher sea levels and more storms that threaten our low-lying coastal assets
  • increased pipe failures due to changes in soil structure and stability
  • large-scale disruptions to electricity supplies.

We're well positioned to deal with future climate challenges, and we'll continue to prepare and adapt where necessary. 

We've considered the impacts of future climate on water supply and demand planning. With other state agencies, we're addressing this risk by diversifying our water supply including:

  • dams
  • water recycling
  • water efficiency
  • desalination.

More recently, we've assessed the impacts of future climate on our:

  • infrastructure
  • operations (water, wastewater, recycled water and stormwater services)
  • customers (so we have fewer service disruptions).

National guidelines for climate change adaptation for water utilities

We co-led the development of the first national guidelines for climate change adaptation planning for Australian water utilities. The project was a Water Services Association of Australia (WSAA) initiative. A total of 17 water utility partners collaborated to produce the guidelines.

The document provides a decision framework that helps utilities understand and manage climate change risk within their business and start to integrate adaptation planning into their planning and decision-making processes. Information is drawn from the extensive experience of the water industry to identify best practice and provide clear principles to guide the industry toward an organised, pragmatic and defensible approach to adaptation.

Learn more about the WSAA Climate Change Adaptation Guidelines 2016 (1.68MB).

Looking forward

We'll continue to look for ways to improve the resilience of our water and wastewater services.