Grid-connected,distributed,renewable cogeneration

Location: Queensland

The site
Woongoolba continues to be a thriving sugar-growing area, with 6500 hectares of land under sugar cane and growers looking to expand into adjoining Shires, in particular Beaudesert. The mill is the largest grower, producing 55,000 tonnes per annum.
The Rocky Point Sugar Mill is the only mill in Australia to produce organic certifi ed sugar and has its own distillery (alcohol factory) on site to convert molasses into alcohol, in particular fuel alcohol. This provides another use for molasses, which was once only used as a stockfeed for cattle.

Sponsors

Sponsors

Sponsors

Technology
Cogeneration occurs primarily during sugar mill crush where a major part of boiler output is supplied as steam to the sugar mill for heat to evaporate water from sugar juice.
The plant was designed to be part of a regional, tertiary-treated, effluent reuse scheme.
All water used in the plant (some 3 -4 ML/day) is sourced from the Beenleigh Water reclamation facility (sewage treatment plant).

Energy purchase and supply
The generator is registered as unscheduled and is an accredited generator under the Green Power scheme. The plant is expected to produce 140 GWh of electricity per annum and is connected to the Energex local electricity network. Power generated from the project is sold to Energex under long-term agreement.
The generator operates 24 hours a day for approximately 300 days a year.

Fuel source
Fuel for the plant is supplied from the sugar mill and from contracts between Stanwell and various councils, including Gold Coast City Council. Biomass consisting of bagasse from adjoining sugar mill in the mill crush with the non-crush fuel being predominately green-waste from Council and woodwaste from nearby Wood Mulching Industries in Cannon Hill.
Green waste from across south-east Queensland is collected and sorted at the newly established green waste handling facilities at Rocky Point.Major transportation firms also benefi t from contracts to transport the biomass to the site.
The problem of a glut of biomass at Council refuse dumps and landfi lls throughout the region will be solved for many years by the commissioning of the Rocky Point Project.

Environmental impact
The project is expected to save 130,000 tonnes per annum of greenhouse gas emissions.
The new plant has replaced previously high emission boilers with more effi cient high pressure boilers resulting in improved particulate emissions (<250 mg/Nm3 down from over 800). In addition,the plant reuses tertiary treated water from the local council.

Owner: Stanwell
Capacity: 30 MW
Location: Woongoolba,55 km south-east of Brisbane
Commissioned: August 2002
Capital Cost: $50 million
Construction Contractor: Alstom Power
Operator: Stanwe