By Andrew Starc
25 June 2010 – Sydney City Council recently announced plans to reinvest the $2 million a year spent on the federal government’s GreenPower scheme into renewable energy for the city, including trigeneration plants to supply 70 per cent of the municipality’s energy by 2030.
But Beyond Zero Emissions director Mathew Wright said that trigeneration was not thinking into the future, and pointed out that the technology still relied on the gas grid.
“Trigeneration was a good option 5-10 years ago. It’s still using the oil and gas networks, the coal fire plants. So the trigeneration plants are peas from the same pod, the power comes from the same thing,” Mr Wright said.
“There’s still a turbine, still a fossil fuel network with trains, trucks, exploration and extraction of gas. Gas needs to be distributed through these networks and there are substantial methane losses through this distribution process.
“We call natural gas ‘dirty dangerous gas.’ [Proponents of trigeneration] usually use the term natural gas instead of methane gas as methane is associated with hazardous environmental implications.
“Cogeneration heats a building directly while trigeneration creates chilling in a building. Melbourne and Sydney are mild climates, there’s a peak in heating and a peak in cooling. [Proponents] say that cogeneration and trigeneration are 55 per cent efficient, but half of the year you’re not using heating or cooling, so the peak efficiency of 55 per cent is only reached on the coldest or hottest day.
“[City of Sydney] should be looking at renewable energy sources like solar thermal and wind. Heat pumps can deliver 3-5 times the energy, which is derived from renewable sources.”
The Sydney City plans are part of Sydney Lord Mayor Clover Moore’s ambition to cut greenhouse gas emissions within the City of Sydney’s local government area by 20 per cent by 2010 and 70 per cent by 2030 from 2006 levels, when 5.5 megatonnes of carbon were emitted in the city area.
The City is seeking tenders for the installation of the trigeneration network, comprising seven plants across central Sydney -Town Hall, Customs House and the city’s five aquatic centres. These systems are expected to have a capacity of up to 25
While the trigeneration is at the top of the agenda for now, City of Sydney will also reallocate funds into solar panels. Future solar projects under consideration include a glass and solar panel shade canopy in front of Customs House at Circular Quay and solar panel roofs on other council buildings such as depots, aquatic centres and other community facilities.
Using both trigeneration and solar power, Ms Moore said the reallocation of funds into renewable energy could provide enough electricity to power up to 75 homes and save the City about $90,000 annually on its energy bills.
“Rather than just offsetting our electricity emissions, this strategy invests the money we would have spent on carbon offsets into building renewable energy projects for the city.
“We’ll also be retiring our Renewable Energy Certificates to increase Australia’s renewable energy capacity and go beyond the Federal Government’s 20 per cent renewable energy target.
“While GreenPower has served the City well, we can now achieve more through smarter investment in renewable energy generation.
“This strategy is part of our work to reduce our emissions by 20 per cent by 2012 through a combination of energy efficiency programs, building energy efficiency retrofits, installation of LED lighting and trigeneration,” said Ms Moore.