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. Treating and pumping wastewater away from homes and businesses 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. This helps us keep bills low.

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
  • 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?

Most electricity in NSW comes from burning coal.

Buying electricity from the grid adds to our indirect carbon emissions and our greenhouse footprint. Indirect carbon emissions can be caused by using or purchasing a product like electricity.

We have a target to keep our carbon emissions at a stable level. In 2020 we kept our non-renewable (grid) electricity purchases at or below 1998 levels even though we were:

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

This replaced our voluntary commitment to be carbon neutral by 2020.

Carbon abatement tool

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

We use the tool to:

  • progress the projects that deliver savings that are greater than costs (the tool shows the cost of starting projects against the amount of carbon emissions saved)
  • prioritise projects that deliver the greatest savings
  • calculate savings delivered versus the capital cost incurred.

We've licensed the Cost of Carbon Abatement Tool to 19 water utilities around Australia. Find out more about the Cost of carbon abatement in the Australian water industry (1,097KB).

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:

  • modifying and replacing conventional lighting with LED technology at several sites. This includes our wastewater treatment plants and laboratories. By changing the lights at some treatment plants, we've saved about $300,000 a year.
  • using smarter mixing techniques at wastewater treatment plants
  • minimising power use by aerators at wastewater treatment plants
  • installing more efficient pumps
  • investing in energy efficient buildings. Both our Parramatta head office and Potts Hill buildings have a 5-star NABERS rating. They also have a 5-star Green Star rating 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're turning waste methane gas (biogas) into electricity and heat. This helps power our wastewater treatment plants.

Biogas is a waste product naturally created during wastewater treatment where wastewater sludge is broken down by bacteria 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 treatment plant and heat. We re-use 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.

We have 11 cogeneration units at 8 sites: Bondi, Warriewood, Malabar, North Head and Cronulla wastewater treatment plants, and at Glenfield, Liverpool and Wollongong water recycling plants.

Producing electricity using the power of water.

We harness the power of water to produce electricity.

Producing water power 

We have 3 hydro-electric (water power) generation plants, which includes a hydro-electric generator  at North Head Wastewater Treatment Plant. 

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

We also produce hydro-electricity 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 treatment plants. 

We're now planning another 300 kW of solar power. If approved, they'll be commissioned in the next 2 to 3 years. 

Turning food waste into energy (co-digestion)

We're investigating how to use trucked food waste streams to increase the amount of energy generated at our wastewater treatment plants.

This innovation could:

  • reduce operating costs, helping us keep bills low
  • 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're investigating 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 Wastewater Treatment Plant. This program proved that a wastewater treatment plant could receive trucked organic waste and convert it to energy for the plant. The program helped Bondi become our first wastewater treatment plant to generate more electricity than we need to run the entire wastewater treatment plant.

On the back of the Bondi plant's success, we introduced co-digestion at our Cronulla Wastewater Treatment Plant – 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 plant to generate over 60% of its own electricity.

Looking forward

We see wastewater plants as potential clean energy generators of the future.

It's possible that some of our wastewater plants will generate more energy than they use in the future 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.

Climate change

We provide sustainable water, wastewater, recycled water and some stormwater services to over 4 million people in Sydney, the Blue Mountains and the Illawarra.

Climate change poses potential risks to, 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 treatment plants 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. 

Over the past 10 years, 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 (worth about $39 billion)
  • operations (water, wastewater, recycled water and stormwater services)
  • customers – so we have fewer service disruptions.

A key tool we use is AdaptWater. It calculates the:

  • consequences of climate change hazards
  • effectiveness of adaptation options to reduce risk.

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 involving 17 water utility partners who collaborated to produce these 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 by reading the Climate change adaptation program (3.6MB)WSAA Climate Change Adaptation Guidelines 2016 (1.68MB) or the Climate Change Adaptation Tool (327KB).

Looking forward

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

We've been recognised as a national leader in preparing for climate change and variability. We received the 2013 NCCARF Climate Adaptation Champion Award in the Business category.