Assessing the energy content of unutilized organic waste in South Africa

Introduction

South Africa is currently highly dependent on coal for energy. Broadening the basis for the South African energy supply through more renewable energy sources is highly desirable for environmental, health, and equity reasons. A quantitative assessment of the carbon content in the current amount of organic waste being generated in South Africa helps establish whether it is feasible to add biogas into the country’s energy mix. Hence in this study, the purpose was to determine an upper limit for the amount of energy that it was technically possible to extract from the carbon content in organic material currently discarded as waste. 

Methodology

The quantitative analysis applied the IIASA Greenhouse Gas Air Pollution and Interactions Synergies (GAINS) model framework to estimate emissions and mitigation potential through biogas production. Data used were obtained from local and international statistical data sources, the guidelines of the Intergovernmental panel on Climate Change (IPCC), and national inventory data submission to the UN Framework Convention on Climate Change (UNFCCC). GAINS allows for the evaluation of alternative control strategies. For the purpose of this study, the amount of carbon that can be recovered for energy production through anaerobic digestion was analyzed.

Results

The table below reveals the estimated biogas potential from organic waste under two assumptions derived from five sectors for 2010 in South Africa.

Conclusion

Results from the GAINS model highlighted that there is significant potential of energy recovery from organic waste. However, in order to mitigate climate change through championing biogas production in South Africa more policy efforts targeted to overcoming technical and non-technical barriers are required.

Please note these Proceedings have received limited or no review from supervisors and IIASA program directors, and the views and results expressed therein do not necessarily represent IIASA, its National Member Organizations, or other organizations supporting the work.

Last edited: 23 March 2015