The cogeneration plant is located at Green Square North Tower in Brisbane within the Green Square Development, one of the largest mixed-use corporate office parks in Brisbane, with a project value of $94 million. The tower comprises twelve levels of office space, 600 square metres of retail space and two levels of parking.

The project incorporates a large scale gas-powered cogeneration plant, in which waste heat from the plant is used to fire an absorption chiller for the production of the air conditioning system’s chilled water. The system sets the standard for future sustainable developments and is a major contributor to the building’s 6 Star Green Star rating achievement.

Commissioned in February 2009, the cogeneration plant – comprising a 775 kilowatt (kW) MTU natural gas engine generator and 800 kW Broad absorption chiller – will contribute to dramatic reductions in the building’s carbon emissions and play a major role in reaching Brisbane City Council’s 2026 target to halve carbon emissions.

Floth Sustainable (previously known, as George Floth) provided the modelling associated with the project’s energy performance outcomes, and estimates that the project would achieve reductions of 26kilograms of CO2/m2/annum (or 65 per cent better than NABERS Energy 5 Star rating).

“Current monitoring of the installation shows that the building is on target to meet this prediction. This has been achieved with the gas engine generator as a part of the cogeneration plant simultaneously producing electricity and useful thermal energy from a low CO2 emission fuel source (natural gas),” says Floth Sustainable Managing Partner in Brisbane Glenn Ralph.

“In addition, localised generation of electricity reduces the demand on the public electrical infrastructure network and eliminates energy losses in the transmission of power to the site,” said Mr Ralph.

Floth Sustainable achieved a 6 Star rating by focusing on optimising the use of existing technologies and systems. These included the adoption of a central plant, low temperature, variable air volume air conditioning system, which delivers optimum temperature and humidity control, tenant flexibility and acoustic isolation, while minimising energy consumption and initial capital expenditure.

About the ACEA

The Association of Consulting Engineers Australia (ACEA) represents the professional and commercial interests of Australian firms who provide leading edge engineering, management and technology based consulting services.

The engineering consulting services industry includes firms supplying civil, structural, mechanical and electrical engineering services, as well as chemical, mining and industrial engineering services. It also includes building consultancy, marine engineering, traffic engineering, construction project management and a range of related technical and management services.

About the awards for excellence

The 2009 ACEA Awards for Excellence is an annual, national event recognising engineering excellence and innovation demonstrated by ACEA member firms.

Over 430 members, clients, sponsors and guests from across the country attended the 2009 Awards, held on Friday 4 December in Brisbane.