Coombabah STP Cogeneration Plant

About the project

Pensar was engaged by the City of Gold Coast for the design and construction of a cogeneration plant and the replacement of ageing water heaters. The new cogeneration unit will use the gas to generate renewable energy and the engine cooling water will heat the digesters. This will reduce plant energy consumption, optimise the use of renewable energy and lower operational costs.

Key Capabilities

Water & wastewater treatment plant works; Pump stations (sewer and water); Mechanical installations; Automation systems/process instrumentation and SCADA

Project Location

Coombabah, Queensland

Client Name

City of Gold Coast

Project Duration

April 2020 - April 2022

Project scope

  • Design and construction works for the civil, structural, mechanical and electrical components to accommodate the new cogeneration unit
  • Supply and installation of a cogeneration unit and ancillaries
  • Supply and installation of new water heaters
  • PLC and SCADA integration


  • Working within a hazardous area
  • Challenging integration into existing system
  • Program and timing restrictions
  • The commissioning phase


  • Successfully improved the hot water circuit system for the digester system
  • Complex pipe installation in a hazardous area installation
  • Lower ongoing power and water costs
  • Successful delivery of a cogeneration system, allowing for the safe use of biomass produced onsite
  • 3D scanning was utilised during the design phase. This technology improved the efficiency and quality of the review process and final design. The use of 3D technologies demonstrated the advantages including enabling risks to be assessed, concepts to be reviewed, and ultimately work to be completed without a high-risk activity within the hazardous area
  • This project received a City of Gold Coast 2021 Work Health and Safety Award for ‘Best Demonstrated Health and Safe Work Design’