A waste water treatment plant in the Sydney suburb of Bondi is being powered by 100 per cent, self-generated renewable energy, after the installation of a cogeneration plant at the facility that captures waste biogas and uses it as a fuel to produce electricity.
The owner of the Bondi Treatment Plant, Sydney Water, said last week that the cogeneration system installed at the plant meant that the energy intensive waster water facility now generated 13 per cent more electricity than it consumed.
In 2015, the total energy produced at the plant was 10,500MWh, while total energy consumed was 9,300MWh, a statement said. The net energy provided back to the grid by the biogas fuelled cogeneration was 1,200MWh – enough to power about 150 households each year. The total energy output of the Bondi plant, meanwhile, is enough to power around 1400 households a year.
As we have reported here before, energy hungry waste water treatment facilities are rapidly being recognised by utilities and local governments as prime candidates for renewable electricity.
In the NSW Riverina Shire of Corowa, the council has installed 100kW ground-mounted systems at both the Corowa and Mulwala Water Filtration Plants, and a 50kW ground-mounted system at the Mulwala Sewerage Treatment Plant (pictured below).
Also in NSW, the Lismore council is in the process of financing plans to install what could be Australia’s largets floating solar PV plant at the East Lismore Sewerage Treatment Plant.
And in Victoria, a water and sewerage treatment plant that services the regional city of Portland, managed by state-government owned utility Wannon Water, will soon be powered by a $2.4 million wind generator.
Sydney Water, meanwhile, is generating more than 20 per cent of its total energy needs across its network through a range of renewable energy projects – including hydro power and 160kW of installed solar plants – and exports 6GWh to the electricity grid over a year.
It says that technologies like the biogas-fuelled cogenerator at Bondi create a number of benefits by taking pressure off the electricity network and by reducing greenhouse gas emissions.
And by eliminating its demand for electricity from the grid, Sydney Water is reducing operating costs which has allowed it to introduce an average reduction in consumer bills of $100 per year over the next four years, effective 1 July 2016.
“Sydney Water is aiming to keep our total electricity purchases below 1998 levels, even though we are servicing an increasing population and providing higher treatment standards”, said Sydney Water’s Kaia Hodge, Manager Liveable City Programs.
“Pumping and treating water and wastewater uses large amounts of energy. By producing our own power on site across all our treatment sites and by exporting it to the electricity grid, we are producing enough energy to power over 11,000 homes each year.
“Sydney Water is trialling additional opportunities for taking commercial food waste at our wastewater treatment plants to increase the amount of biogas produced from anaerobic digestion and to increase energy yields.
“In addition to clean energy generation, Sydney Water is implementing cost effective projects to reduce energy use”, said Hodge.