Looking past coal to mine dumps and sewers

Sydney Morning Herald
Friday 3/12/2010 Page: 4

THE bright tights of Sydney's central business district will be powered by rotting agricultural waste and sewage harvested from a 250-kilometre radius around the city, under a new plan to move away from coalfired energy.

The city's master plan relies on 27 existing or proposed trigeneration plants, mainly concealed in the basements of public buildings and city offices, to free the city of its dependence on the Hunter Valley coal that accounts for 80% of central Sydney's greenhouse gas emissions. The gas-driven trigeneration plants would convert plant matter to biogas, helping to cut the city's carbon emissions by 70% by the middle of the century. Meeting the target would put Sydney at the forefront of global cities converting from high to low carbon energy.

The plan comes as the World Meteorological Organisation prepares to release its annual review this morning, showing that 2010 has been one of the three hottest years on record, in line with the projections of the Intergovernmental Panel on Climate Change.

The City of Sydney's plan could reduce household electricity bills across the state, which have risen sharply recently to pay for new infrastructure to support the existing coal-based network. The council believes it can reduce the need for spending on new transmission infrastructure by generating energy locally and improving efficiency.

"We set an ambitious target to reduce greenhouse gas emissions by 70% by 2030", said the Lord Mayor, Clover Moore. "We made that commitment not because we thought it would be easy but because the best available research said it is needed to play our part in diverting catastrophic climate change".

The council estimated the cost of the project - which it expects will include public-private partnerships would be $950 million over 20 years, and would show a 10 to 20% return on investment for trigeneration operators.

"It sounds a lot but in comparison the NSW energy companies are set to spend $17.4 billion over the five years to 2014 on upgrading the electricity network of wires, poles and substations", Cr Moore said. And the NSW government has given consent and concept approval to two new coal-fired power stations at the cost of $7 billion".

Allan Jones, the city's chief development officer for energy and climate change, said trigeneration plants would be cheaper than many sources of renewable energy. They would also costless than coal-fired power with carbon sequestration, in which emissions are pumped underground so they do not enter the atmosphere.

"There is no single silver bullet here we do need decentralised energy, we do need renewable energy, we do need measures to be undertaken around transport", Mr Jones said. " [Trigeneration] is more economic than large-scale wind, solar PV [photovoltaic] and way, way more economic than coal-fired carbon capture and sequestration".

The speed at which the plan can be implemented will depend upon the introduction of a national carbon price, which will add some of the costs of greenhouse emissions to heavy polluting sources of power, and therefore make low-carbon power more competitive. A tender period for companies hoping to build and operate the trigeneration plants will close in January, and construction is expected to begin on several of them at once in 2013.