Sydney Water is Australia’s largest water utility and is among the ten most largest water utilities in the world. The utility provides water, recycled water and wastewater services to 1.4 million properties and 4.8 million people over a supply area of 12,700 square kilometers across Sydney, the Illawarra and the Blue Mountains. Like all utilities Sydney Water is faced with a number of current and emerging challenges that threaten its ability to continue delivering water at affordable prices including population growth, concerns about the cost of living, greater customer expectations and climate change.
To meet these challenges the utility aims to become more efficient in providing high quality water and services to its customers. As part of this efficiency drive, Sydney Water is proposing to lower its prices for customers over the 2016-2020 period, resulting in most households saving over $100 on their water and wastewater bills each year.
To increase efficiency and pass on the savings to customers, Sydney Water is working towards reducing its energy use by improving energy efficiency in its operations and generating renewable energy. The aim is to keep its non-renewable energy purchases at or below 1998 levels as well as cap its carbon emissions at a stable level.
Sydney Water’s energy efficiency program
To date the utility has saved almost 30 GWh of energy: the equivalent of saving electricity used by 4,100 homes a year. This has included:
- Using smarter mixing techniques at its wastewater treatment plants (WWTPs)
- Minimizing power use by aerators at WWTPs
- Investing in energy efficient buildings. Both the utility’s Parramatta head office and Potts Hill buildings have a 5-star NABERS rating and a 5-star Green Star rating from the Green Building Council of Australia
- Replacing conventional lighting with LED technology at several sites, including WWTPs, saving around $130,000 a year
Sydney Water’s renewable energy program
Over the period 2013-2014, Sydney Water generated 16% of its energy needs from renewable sources: enough to power over 9,000 homes a year. This has been achieved by:
Recovering energy from wastewater: Sydney Water turns waste methane gas (biogas) into electricity at its WWTPs and water recycling plants, as well as reusing waste heat in WWTP processes.
Generating hydroelectricity: Sydney Water produces hydroelectricity at its North Head Wastewater Treatment Plant. At this plant wastewater passes down a long drop shaft on its way to a deep ocean outfall with energy captured by a hydroelectric generator. The utility also produces hydroelectricity in its water supply pipelines at two dams.
Capturing the sun’s rays: Sydney Water produces around 60 kW of solar power at their Potts Hill Office, enough to power most of the office lights. In addition, the utility has installed solar hot water systems in most of its buildings. Sydney Water will install a further 100 kW of solar power across a number of its sites.
Turning waste into energy: Sydney Water is exploring the use of trucked waste streams to increase the amount of energy generated at its WWTPs. The waste streams the utility is investigating include glycerol, commercial and household food waste, beverage and dairy waste, and fats, oils and grease.
Sydney Water becoming a utility of the future
Going forward, Sydney Water sees WWTPs as potential clean energy generators with the possibility that some of its WWTPs will generate more energy than they will use by:
- Becoming more energy efficient,
- Maximizing energy capture from wastewater
- Adding new organic waste streams
In the meantime Sydney Water will aim to increase its renewable energy mix and implement cost effective projects to reduce energy use and carbon emissions in its overall operations.
Water utilities can implement energy efficiency and renewable energy projects to reduce operational costs and pass on the savings to customers.