Sustainable Sydney 2030 targets a 70 per cent reduction in greenhouse gas emissions in the City of Sydney Local Government Area compared to 2006 levels. Around 80 per cent of the city’s greenhouse gas emissions come from power generation, primarily coal-fired power stations. Trigeneration runs on natural or renewable gas and is more than twice as energy efficient as a coal-fired power station.

Trigeneration will play a significant role in achieving the City of Sydney’s emission reductions target.

Trigeneration generates three forms of energy – cooling, heat and power. Natural or renewable gas is burned in an engine that turns a generator to make electricity. Like your car, the engine gets hot. Like the heater in your car, the heat from the engine can be captured and used – in this case it’s used for heating buildings and hot water. Through a process called absorption cooling, which works like a fridge in reverse, the heat can also be turned into cooling, and can be used for air-conditioning.

There are already trigeneration plants operating in buildings in the Sydney such as Westfield and Stockland. However, our plans take the technology to the next level where trigeneration will work as a precinct network which buildings can connect to for their energy, heating and cooling.

The benefits of Trigeneration

Trigeneration is powered by natural or renewable gas, and gas is about 40 per cent cleaner than coal. Most emissions in the local government area come from commercial buildings which use a lot of heating and cooling. The trigeneration network proposed by the master plan would be equivalent to a 800-1000 megawatt coal-fired power station. However, using trigeneration would significantly reduce our city’s emissions and create a far more efficient power supply.

Avoids expensive electricity upgrades

The City’s trigeneration master plan estimates the cost of 360 mega watts (MW) of trigeneration capacity at $440 million (2010 dollars), to provide 70 per cent of the Local Government Area’s electricity requirements by 2030.

A trigeneration network in the City of Sydney could save NSW energy consumers up to $1.5 billion slated for new coal or gas-fired power stations and upgrades to the electricity grid by 2030, according to a study by the University of Technology, Sydney. Trigeneration plants produce energy locally and help to avoid expensive upgrades to the NSW electricity grid of poles and wires which have pushed up power prices.

Network charges – the cost of poles and wires – are 50 per cent and the largest component of the average electricity bills which have risen more than 70 per cent over the past five years.

How it works

Gas supplies

The City’s proposed trigeneration network will be supplied by the Sydney natural gas distribution network which supplies households and businesses. By 2030 the City’s trigeneration project is estimated to account for only 3 per cent of projected demand for gas in NSW with the majority expected to come from large-scale gas-fired power stations and exports.

In addition, the City’s trigeneration project will reduce electricity consumption by 30 per cent by using waste heat to replace electric heating and cooling of buildings. This would reduce gas demand compared to gas-fired power stations.

Air quality

The trigeneration plants will be fitted with the latest air quality control technology, including selective catalytic reduction systems similar to devices in the exhaust systems of modern cars. This will reduce NOX emissions to 50mg/m3 of air compared with NSW air quality standards for Sydney of 250mg/m3.

Renewable gases

The City is also investigating the use of renewable gases, extracted from garbage, livestock and crop waste, to replace natural gas as a fuel for its trigeneration plants. A plan detailing the potential of all types of renewable resources close to the city will be released later this year.

The path to the Master Plan

The best way to reach our emissions targets is to create trigeneration zones, or shared plants, that could be used by all the buildings in a precinct. The City of Sydney has developed a Master Plan that determined exactly how many trigeneration hubs we required, how big they had to be, and where we needed to place them, so we could assess the scale and costs of this new green infrastructure.

The City worked with Kinesis to develop the Trigeneration Master Plan to detail the impacts and benefits to Sydney, the anticipated infrastructure, case studies and actions to make the technology a reality. The plan shows precinct scale trigeneration is the most cost effective way after energy efficiency, to reduce greenhouse gas emissions in Sydney.

Key details of the Master Plan

Four Low Carbon Infrastructure Zones and precinct scale trigeneration hotspots

The Trigeneration Master Plan established that trigeneration could be implemented in four Low Carbon Infrastructure Zones – CBD North, CBD South, Pyrmont/Broadway and Green Square. As well as these zones, four precinct scale trigeneration ‘hotspots’ could be implemented at the University of Sydney; Australia Technology Park and Carriageworks; the Entertainment Quarter near Centennial Park; and the industrial precinct in the south of the local government area. There is also potential for small scale fuel cells in other areas of the local government area.

Sydney case studies

Detailed case studies are included on existing buildings in the CBD North, CBD South and Pyrmont/Broadway low carbon zones to inform building owners and tenants of the typical requirements, potential costs and savings from connecting to the trigeneration network. The case studies include a range of building types including Highgate, a high rise residential tower, Broadway Shopping Centre, University of Technology Building 10, and two commercial office buildings.

Reduction in greenhouse gas emissions

Connected buildings in the four Low Carbon Zones would reduce greenhouse gas emissions by up to 56 per cent. Taking into account the additional hot spots, trigeneration will reduce emissions across the local government area by up to 32 per cent. This is a significant contribution to the City’s 70 per cent emissions reduction target by 2030.

What’s next?

The City of Sydney has since signed a Heads of Agreement with Cogent Energy, owned by Origin, for the building and operation of the trigeneration energy network. This network will supply the city and privately owned buildings in four areas: CBD North, CBD South, Pyrmont/Ultimo and Green Square.

Further emissions reductions will be driven by the City’s Renewable Energy and Advanced Waste Treatment Master Plans which will be reported on later this year.