Australia’s sugar mills are almost self-sufficient in energy. By burning the fibrous cane by-product, bagasse, mills generate electricity and steam to power all factory operations.
Sugar mills also generate additional renewable electricity to export to the National Electricity Market (NEM). Unlike wind and solar, cogenerated (biomass) power generation provides a reliable source of renewable power at any time of day. Cogeneration based on bagasse is renewable because the sugarcane crop that produces it can be continually regrown.
Queensland’s 21 sugar mills currently have 405 MW of installed cogeneration capacity in producing approximately 1 million MWh of electricity annually. Around half is exported to the grid (enough to power 109,000 dwellings per year or 25% of all Brisbane dwellings)*. The recently completed co-generation facility at MSF Sugar’s Arriga Mill, located near Mareeba in Far North Queensland has added 24 megawatt capacity to cogenerate additional electricity – enough to power a further 26,280 homes. The facility represents a $75m investment
The by-product from the crushing of sugarcane, bagasse is recycled and used as boiler fuel in the sugar mills. It is burned at temperatures of up to 400-800 ºC to produce steam, which is either used as heat for the milling process or to drive turbines that generate electricity. This process is called co-generation.
Sugar mills generate over a quarter (27%) of Queensland’s renewable energy, which meets more than 2% of Australia’s large scale renewable energy target.
*Using ABS estimate: 4.6 MWh consumed/dwelling/per year (AEMC 2017 Residential Electricity Price Trends) and 25% homes in Brisbane (109,000 dwellings).
One truck load of bagasse stores enough energy to power two Queensland homes for more than a year.