Combined with various small-scale improvements – such as optimising its pump systems and equipment – the utility expects to slash a total of a quarter of its electricity demand. The savings result from implementing opportunities identified under the Federal Government’s Energy Efficiency Opportunities program.
Under the program, Sydney Water conducted energy efficiency assessments at four sewage treatment plants, three water pumping stations and two sewage pumping stations. The nine facilities consume 40% of the its energy needs.
The utility supplies over 1.3GL of water to more than 1.7 million homes and businesses everyday from 156 pumping stations. It then collects and treats more than 1.5GL of wastewater daily at 31 sewage treatment plants. In doing so it uses in excess of 1.6 petajoules (PJ) of energy annually.
Under the Energy Efficiency Opportunities (EEO) program, businesses that use more than 0.5 PJ in a year – roughly the amount used by 10,000 households – are required to identify, evaluate and report publicly on cost effective energy savings opportunities within their operations. About 210 corporations are registered on the program.
According to many of the assessments released recently on the EEO website, most businesses have identified cost-effective opportunities and many are adopting them.
Sydney Water energy manager Daniel Cooper told Environmental Management News that the improvements they’ve undertaken have multi-pronged benefits: it cuts emissions, adds to the utility’s green credibility and yields financial returns.
Under the EEO assessment, Sydney Water identified 104 opportunities to save on electricity demand, with a varying range of payback periods. A total of 48 are either underway or are in the process of being implemented. These include eight cogeneration and hydroelectric plants that will be operational by mid-2009, adding to three such existing facilities that are already running.
Cogeneration captures biogas from the wastewater treatment processes to create heat and electricity, while hydroelectricity energy is generated from water and wastewater flows within the pipe network.
Other methods of savings include real-time pump scheduling of water supply systems, running pumps closer to their best efficiency point, optimising control and use of equipment within treatment plants, optimising aeration systems “and a number of smaller project that will add up benefits to the organisation,” Cooper says.
“The reason for doing this is the ongoing benefits and the lower operating costs that you end up with [by] implementing these projects.”
Rising fuel prices have also made investing into renewable projects more cost effective, while programs like the EEO and other government policies are also helping.
Upping energy efficiency is also helping the utility in its stated commitment to “become carbon neutral in our energy use” by 2020. It has pledged to cut down its carbon emissions by using in-house capacity to generate renewable energy and through the purchase of offsets.
“Any other water utility can take advantage of [wastewater], or [rubbish] tips if you’re in the waste industry,” he said. Energy efficiency can come in various ways, he added, such as through fitting “variable speed drives on the pumping units, improving the controls of those pumping units, improving controls of industrial plants”.