Commonwealth Bank Place Case Study
The $500 million Darling Quarter project is a collaborative effort between Lend Lease and the Sydney Harbour Foreshore Authority. The project includes a commercial development 'Commonwealth Bank Place', and a family and leisure precinct with retail and dining options, a new public park and car park. The Commonwealth Bank Place building at Darling Quarter will house over 6,000 Commonwealth Bank of Australia employees. The Lend Lease project team was tasked with designing and constructing buildings with superior environmental and efficiency standards. While lowering operating costs was an objective, lowering carbon emissions and the use of environmentally friendly materials were key elements of the project.
Environmental and energy efficiency can be achieved through the use of distributed cogeneration and trigeneration technology. A cogeneration system utilises the waste heat created from a reciprocating piston or gas turbine engine that is used to drive an alternator for the production of electricity. The waste heat from the engine is then used for heating water to substitute conventional heating methods. In the case of a trigeneration system, the addition of an absorption chiller means that hot water is being used to produce chilled water; this then replaces or reduces the scale of traditional chilled water equipment.
Electricity generated at a coal fired power station typically has an overall efficiency of 25 per cent including transmission losses. Cogeneration and trigeneration, as distributed power, utilising gas engines can have electrical efficiencies of up to 42 per cent. With the reuse of waste heat, the total system efficiency can increase to greater than 80 per cent, offering significant efficiency gains compared to a coal fired power station. These efficiency gains translate to a significant reduction in carbon emissions, not just from the efficiency gains but the use of gas fired engines also reduce carbon emissions by approximately 30 per cent compared to traditional coal fired power stations. Many business models have been formulated with relatively short payback periods through energy cost reduction alone.
The optimisation of a Cogeneration or trigeneration plant is essential to achieve the highest efficiency. One of the key elements is load maximisation to ensure as much waste heat is consumed to attain the highest efficiency.
Cogeneration and trigeneration plants are typically used on a continuous basis as opposed to standby. The design of continuously operating plant is far more demanding than standby plant; heavier loading wear and tear tolerance with high availability is a primary design consideration.
Depending on the technology selected, either gas turbine or reciprocating engine, the application of load to the system may need to be controlled. That control can take many forms, either load application control or support from the main power grid.
Financial institutions demand highly reliable power and availability; the Darling Quarter facility had the added requirements of meeting an efficiency target. Achieving a “6 Star” green star rating was of great importance for this particular project
MPower’s solution was to implement and integrate 2 x 400kWe MWM natural gas generators into the tri-generation system. These engines were selected due to their high efficiency. The two generators supply hot water to a York absorption chiller which at full capacity can provide up to 500kWr of cooling in the form of chilled water.
The trigeneration system is integrated into the building’s BMCS (Building Management and Control System) and EWMS (Energy and Water Management System) resulting in the ability to monitor the power consumption of the building base load whilst controlling generator output to maximise efficiency. MPower also installed 2 x 1650kVA back-up emergency generators.
MPower utilised its in-house team with industrial process control expertise, designed the mains power synchronisation connect and disconnect system as well as a process control system that controlled the base trigeneration package. The plant design and pipe work posed complex control problems that the entire team resolved.
The MPower business differentiating strategy of being an independent power systems integrator with full in-house capability is ideally suited to these applications.
MPower’s asset management team of fully qualified and certified service technicians provide onsite 24/7 service and support giving Lend Lease peace of mind and reliable power generation.