The City of Sydney Council is dealing with a chiller controversy that has left property owners out in the cold.
The recently re-elected Lord Mayor of Sydney, Clover Moore, is passionate about plans to make Sydney one of the leading green cities in the world. However, it seems that the council’s trigeneration master plan contains a few technical issues that have been overlooked.
Work on the plan, which covers the City of Sydney local government area, is already underway. In fact, Moore says the network will take “most, if not all, of the buildings in the city off the coal-fired grid”.
Clearly it is a noble plan, but as many pundits find out the hard way, the devil is in the detail. Nobody, it seems, has explained to the council the difference between regular chillers and absorption chillers.
When it was first announced, Moore explained that trigeneration was three times more energy efficient than coal-fired power stations.
“Trigeneration runs on natural gas and produces low carbon electricity, heating and air conditioning for clusters of surrounding buildings,” she said.
These clusters have been created by carving up the city into sections, with Sydney now containing four low carbon zones.
The city’s low carbon, green future sounded fine until the Property Council of Australia held a forum for building owners to review details of the plan.
Proceedings hit a snag when someone asked building owners how the supply of low GHG energy would be hooked up to each building.
The council said the plan was to use a hot water reticulation system for heat exchange, instead of a chilled water system.
The hot water system works by bringing hot water, produced by waste heat from electricity generation, to a building. An absorption chiller then converts the heat to chilled water for cooling.
This news wasn’t welcomed by building owners. They weren’t too keen on replacing their regular chillers with absorption chillers. which are much bigger and heavier than the old models.
According to news website The Fifth Estate, forum moderator Steve Hennessy had the challenging task of diplomatically summing up the issues.
The absorption chillers, Hennessy explained, might not fit the spaces occupied by the old chillers, such as on the rooftop. They also might not have the load bearing capacity for the extra weight.
The new chillers might be fitted into the basement, but that would mean the pipes would need to be rerouted at significant cost.
How these technical hiccups will be overcome is yet to be decided, with some owners fearing the cost of the trigen system may be too high.
Besides the chiller issue, owners also want to know how to attribute the greenhouse gas co-efficient of electricity produced by the gas-fired trigen plants.
Property owners have spent months sifting through the plan identifying what is feasible and what could be a pipe dream.
Full details of the city’s master plan were posted online in July, while submissions to the council closed in September.
Since then the council has announced it is negotiating an agreement with Cogent Energy, a subsidiary of Origin Energy, to move ahead with the master plan.
Trigeneration energy will supply 100 per cent of the council’s energy requirements, with the first plant operational by 2014, the council said in a statement.
In the meantime, Solgen is currently installing 1.4Mwe of solar photovoltaic systems across council-owned sites to provide a quarter of the city’s electricity needs.
“Stand-alone trigeneration plants are already being used by a number of companies in Sydney including GPT Group, Stockland, Investa and Westfield,” Moore said.
“However, the city’s plan goes much further, with trigeneration networks to supply precincts or clusters of buildings similar to Europe, the USA and Asia.”
The mayor pointed to a study by the University of Technology, Sydney (UTS) which estimates the project could save up to $1.5 billion in avoided capital investment in new coal-fired power stations and grid upgrades.
