Attilio Pigneri

16 July 2013 — In a world first, the City of Sydney has found a secure and competitive supply of renewable gases for its proposed trigeneration network thanks to the Renewable Gas Supply Infrastructure study.

Renewable gases are gases derived from thermal (synthesis gas) or biological conversion (biogas and landfill gas) of residual waste and biomass resources, and upgraded into pipeline-quality substitute natural gas.

Renewable SNG can be then stored and delivered through existing natural gas infrastructures, providing a reliable and flexible supply of renewable energy for stationary energy and transport applications.

Attilio Pigneri, managing director of TWE, which undertook the study for the City’s Renewable Energy Master Plan, said it was the first time an assessment of this type had been carried out anywhere in the world.

“While the injection of upgraded biogas into existing pipelines is now standard practice in several countries – Germany, United States and Denmark to name a few – the concept of a regional network of gasification and anaerobic digestion facilities supplying renewable SNG to a decentralised network of tri-generation facilities is unique to the strategy under development at the City of Sydney,” he said.

In August 2012 the Council of the City of Sydney passed a resolution to supply the entire tri-generation network with renewable gases by 2030.

“By committing its proposed tri-gen network to a 100 per cent renewable gas supply the City is playing a crucial role towards the development of a renewable gas market,” Mr Pigneri said.

“The resulting demand will provide the certainty investors will require to develop new renewable gas generation capacity and the infrastructure to inject renewable SNG into existing pipeline networks.”

Previous analyses conducted within the scope of the City’s Renewable Energy Master Plan have put the total potential associated with residential and commercial solar and small-scale wind at only 18 per cent of the City’s electricity needs.

“This has been the main motivation for the City to engage in the Renewable Gas study,” Mr  Pigneri said.

“When it comes to achieving deep reductions in greenhouse gas emissions and moving towards 100 per cent renewable energy supply – energy, that is, not just electricity – we need to look beyond solar and wind generation alone and identify other non-intermittent renewable energy resources that can provide the same time-of-use and place-of-use flexibility provided today by conventional fuels.”

The study has provided an in-depth analysis of the renewable SNG potential associated with residual waste and biomass resources available within 250 km from the City of Sydney, covering the key dimensions of technology, resource, economics and greenhouse gas emissions.

That has doubled the projected requirements from the trigeneration network by 2030 with the cost also becoming competitive with projected natural gas prices starting from 2020.