Converting Waste Into Energy
Sewage has traditionally been viewed as a waste product, but Melbourne Water is continuously investigating and implementing projects which use sewage as a resource, not only as recycled water, but also to create energy.
Renewable energy at the Western Treatment Plant
We are using the sewage at our Western Treatment Plant to produce nearly all of the plant’s electricity needs. Electricity is generated from biogases captured in covered treatment lagoons. Biogas, mainly methane, is a by-product of sewage treatment.
More generators have been installed so the facility can produce about 95% of its annual electricity needs. For parts of the year, the plant is likely to be producing more power than it needs and the excess electricity will be exported to other Melbourne Water sites.
71,500 megawatt hours of renewable electricity are generated at the Western Treatment Plant every year from the biogas captured, and the reduced reliance on imported electricity prevents the emission of the equivalent of more than 87,000 tonnes of carbon dioxide every year.
Renewable energy at the Eastern Treatment Plant
We have upgraded the power station and outfall pumping station at our Eastern Treatment Plant so that biogas can be used to generate electricity for the plant. This renewable energy source will reduce greenhouse gas emissions by replacing imported electricity and by almost eliminating the use of diesel fuel at the plant.
The project provides about half the energy needed to run the plant and most of its heating and cooling requirements. The seven generators can run solely on biogas or can be supplemented by natural gas as needed. New electric motors now power the outfall pumping station.
This project has resulted in an increase in renewable energy use and less dependence on importing electricity.