Given the potentially harmful emissions – is the burning of waste for electricity generation considered sustainable practice?
This is an excellent question. Australia produces an astounding 70 million tonnes of waste annually and we need to deal with all this rubbish we create. In terms of plastic alone, in 2017-2018, some 3.4 million tonnes of plastic were used in Australia. Of that just 320,000 tonnes (only 9.4%) were recycled.
Historically, most of our waste has gone to landfill. About half of the waste we currently produce is able to be recycled, but Australia has recently seen a problematic breakdown in its recycling systems. We have partly dealt with the problem in recent years by shipping recyclables offshore to countries like China and Malaysia for processing. While dumping our rubbish in other countries is far from acceptable, shipping a “high quality” waste stream of recyclable material for effective processing and re-use is one way to make our global economy more circular. In 2018, though, China banned waste imports from Australia, and then in late 2020, Australia prohibited sending its own unprocessed waste overseas, partly to stimulate recycling systems in Australia.
Given we have so much waste to deal with, and only part of it can be recycled, much of the rest ends up in landfills. This is a problem in relation to climate change. Organic waste in landfills produces the greenhouse gas methane. Some landfills collect this for energy generation – not all – and the rest ends up in the atmosphere as a potent climate heating gas.
So could burning some of our waste be a better way to deal with it if it also produces energy from non-recyclable waste that would otherwise be sent to landfill? In terms of carbon accounting, waste-to-energy plants may potentially reduce greenhouse gas emissions. Australia’s biggest waste-to-energy plant at Kwinana in WA says it allows 486,000 tonnes of carbon dioxide emissions to be avoided each year. Australia now has two recently built state-of-the-art waste to energy plants, both in Western Australia. These plants emulate a technology that is becoming increasingly common in Europe and, if they are powered by material that is considered renewable – as designed to do – then they are considered by the Australian Renewable Energy Agency (ARENA) as a form of renewable energy. The ash which is the byproduct of this incineration process can be re-used, for example, in road building.
Despite being what sounds like a good solution to dealing with waste, incinerating rubbish is not without problems. There are certainly toxic chemicals associated with the process. Just one example, dioxins, a highly toxic and persistent organic pollutant, have been found in higher concentrations around waste incinerators. Above all, waste-to-energy plants ultimately also undermine a circular economy: they need us to keep producing large amounts of waste to keep going. If we are truly going to deal with waste in the most sustainable way, we need to produce less of it, and keep recycling materials. Needing waste to burn supports the continued production of waste, and ultimately, that’s not good for the planet. Overall, then, it's not a very sustainable practice - but it may have a use for some kinds of waste and in some places.
