An evaluation of the potential of waste to energy technologies for residual solid waste in New South Wales, Australia

The state of New South Wales (NSW) accommodates the largest population in Australia and is responsible for more than one-third of all waste generated in the country. An effective and economical waste management can be achieved by using waste to energy (WtE) technologies to manage residual wastes and produce energy. The aim of this study was to investigate the potential of the WtE technologies for energy recovery and greenhouse gas (GHG) emission reduction in NSW. In this study, major streams of wastes (municipal solid waste, commercial & industrial waste, construction & demolition waste) in NSW were classified into combustible, non-combustible and food organic waste. Four waste management scenarios using different combinations of WtE technologies, such as landfilling with energy recovery, incineration and anaerobic digestion (AD) were applied to evaluate electricity generation and GHG emission potentials from all these wastes. The results indicated that by employing a combination of incineration and AD for combustible and food parts of residual waste in NSW about 4165 GWh of electricity could be generated annually, which is equivalent to about 5.9% of the total electricity generation in NSW. This conversion of WtE leads to a reduction of about 1.7 million tonnes of GHG emissions annually. In this way, about 3 million tonnes of residual waste could be diverted from landfills in NSW annually which would offer approximately 50% reduction in landfilled waste by weight. Findings of the study showed that employing incineration and AD technologies could exploit a considerable amount of energy from residual waste and mitigate GHG emissions. Furthermore, employing efficient WtE technologies would divert organic waste out of landfills, avoiding emissions from landfills and will contribute to a greater share of renewable energy production, thereby reducing emissions from fossil fuel power plants.