An independent sustainability coach has slammed parts of the City of Sydney’s Renewable Energy Plan adopted at a council meeting on Monday.
Michael Mobbs, a former environmental lawyer now associate lecturer at the University of Technology, described points of the plan related to anaerobic digestion of food waste as “deeply misleading” and “obscene”.
Anaerobic digestion uses microorganisms to break down biodegradable waste in the absence of oxygen.
Mr Mobbs told City News that “burning” food waste leaves almost no waste to compost for soil revival which is essential for growing food.
“When we burn food waste we burn soil. It’s just madness,” he said. “The ultimate result of such a regime – a city which burns food waste to make energy – is that we may have energy but no soil to grow food.”
But the City’s report pre-empts this criticism. “There is a misunderstanding by some that anaerobic digestion renewable gases derived from waste somehow destroys the organic material and its potential to be used as a fertiliser,” the plan states. “This is not the case.”
City of Sydney chief development officer for energy and climate change, Allan Jones, told The Bondi View it was a nonsense to talk of “burning” food waste.
“The food waste itself is not burnt – it’s actually decomposed in the same way as compost,” he said. “You can’t burn organic waste, it’s mainly water.”
Mr Jones said concerns about soil revival are baseless because anaerobic digestion kills the pathogens you get in traditional composted material.
“The digestate [material remaining after anaerobic digestion] is dried and reformed into a fertilizer. And that is a higher nutrient quality than conventional composting.
“You get far more value out of organic waste from anaerobic digestion than you do from aerobic digestion [composting], which is why they’re switching to anaerobic digestion right across Europe.”
The City of Sydney’s Final Decentralised Energy Master plan also resolves to pursue a target of 100 per cent locally-produced renewable energy by 2030.
The Renewable Energy Plan is one of five interrelated master plans that propose to reduce the greenhouse gas emissions of the local government area (LGA) by 70 per cent below 2006 levels as part of Sustainable Sydney 2030.
Greens councillor Irene Doutney praised the Master Plan for identifying potential energy sources as well as potential roadblocks.
“The Decentralised Energy Master Plan is an important document because it analyses the potential sources of energy that could be used to make the City’s energy self sufficient into the future,” Ms Doutney said.
“It also gives a rigorous analysis of how likely it is that this can be achieved and recognises the barriers that face us.”
Ms Dountey said renewable energy is a growing industry and the adoption of the new plan has the potential to generate more jobs.
“Currently there are 1340 companies in Australia working in the renewable and clean energy sector employing 53,000 workers.
“Renewable energy is an emerging technology and as it grows it will inevitably create more jobs.”
But Liberal councillor Edward Mandla has doubts about the capacity of the plan to reach its targets.
“You’re telling me it’s going to generate 100 per cent of its electricity for the LGA from renewable sources by 2030?” he asked. “It’s a bit farfetched.”
Mr Mandla moved an amendment to include the following statement on each page of the Master Plan: “The implementation of the Master Plan cannot be delivered by the city alone, and without regulatory change nor can the outcomes be realised in a short time frame.”
The amendment was supported by fellow Liberal Christine Forster but not by any other councillors.
With Michael Koziol