A low-carbon trigeneration plant is now powering, heating and cooling Sydney Town Hall and neighbouring Town Hall House, where 1,500 City of Sydney employees work.
Trigeneration is a low-carbon form of energy production, producing less than half the carbon emissions of the coal-fired plants that generate around 80 per cent of Sydney’s electricity.
The contract for the Town Hall trigeneration plant was awarded in early 2015, with the plant becoming operational 18 months later.
Delivery of the project was preceded by years of thorough investigation and documentation to ensure that the system would be commercially viable and technically feasible.
After being gradually phased in, the plant is now fully supplying the city’s civic buildings on working weekdays from 7am to 10pm.
Sydney Lord Mayor Clover Moore said the 1,400 kilowatt system was expected to cut carbon emissions by more than 40,000 tonnes over its 30-year lifetime, equivalent to 1,500 small cars.
“Installing trigeneration power at Town Hall is already helping us reduce our reliance on coal-generated energy hauled in from the Hunter Valley, and allows us to power, heat and cool our buildings from a clean, local supply,” the Lord Mayor said.
“Decentralised plants like this one offer the grid more reliability. As well as meeting the weekday energy needs of Sydney Town Hall and Town Hall House, the rooftop generation plant is ready to export significant amounts of electricity to the grid. This could help manage peak power demands and defer costly investment in electricity network upgrades.”
The plant uses seven 200kW capstone micro-turbines that can each turn down to a tenth of their total power output, meaning they can follow the electrical demand in the building during both summer and winter months.
Micro-turbines were chosen for Town Hall because they were cost-effective, easily integrated into the existing grid and provided greater reliability than reciprocating engines for the building’s particular circumstances.
Trigeneration is an extremely efficient decentralised energy technology where electricity is made near where it is used, avoiding the need to transport electricity over long distances. It replaces coal-fired electricity and reduces emissions from connected buildings.
Producing energy locally helps avoid expensive upgrades to the NSW electricity grid of poles and wires which have pushed up power prices. Consumers are forced to pay for upgrades to an aging and inefficient network that moves coal-fired electricity from the Hunter Valley to Sydney.
According to Chris Barrett, Commercial Manager, Green Infrastructure, the trigeneration plant has reduced electricity consumption at Sydney Town Hall by more than 50 per cent. In addition, the plant is on course to generate 2,800 megawatt hours of electricity per year.
The plant reduces carbon emissions by around 1,500 tonnes per year, or three per cent of the organisation’s annual emissions.
“The plant uses a series of pumps to push waste heat through the trigeneration system and to send the energy to the rest of the building as cooled or hot water,” said Mr Barrett.
“Equipment used for the project includes waste heat recovery equipment, absorption chillers, circulation pumps, heat exchangers and a range of system controls.
The plant has been exporting to the grid since it came into operation in mid-2016.
Leading by example
Trigeneration plants are growing in popularity as they represent a cleaner and cost-effective option for commercial-scale energy generation, particularly where the size of the site restricts large scale renewable generation.
Trigeneration already operates in many properties across Sydney, including commercial buildings like Qantas Flight Services, Google, 1 Bligh Street, 133 Castlereagh Street, 20 Bond Street; leading community clubs like Rooty Hill RSL and Castle Hill RSL; and multiple local governments like Hornsby, Leichhardt, North Sydney, Willoughby and Wagga Wagga Councils.
The city is investing in a number of other trigeneration and cogeneration systems at the Ian Thorpe Aquatic Centre and the Green Square Aquatic Centre.
“Trigeneration is part of our practical portfolio of sustainability programs to cut carbon emissions by 70 per cent based on 2006 levels, along with building retrofits for energy efficiency, installing solar panels on the buildings we own and offsetting carbon emissions,” said the Lord Mayor.
“We’re leading by example. The city is Australia’s first carbon neutral government and we’ve already reduced emissions in our own buildings and operations by 27 per cent on 2006 levels.”
The city has pushed for changes to Federal energy regulations to allow decentralised energy generators to be provided with credits for exporting power to the grid.
The City of Sydney received a grant of $3.05 million from the Federal Government’s Community Energy Efficiency Program for the trigeneration project. The system was designed and installed by leading national building services contractor AE Smith.