Recognising the change in land use patterns and its impacts on energy demand and emissions in Gauteng, South Africa

The economic powerhouse of South Africa, Gauteng, has seen rapid urban growth since its formation in the early nineties. Today, more than 90% of its population lives in urban areas. The sudden rapid urban growth over such a small period has resulted in dispersed spatial structure. The thesis aims at recognising the change in the land use pattern and its impacts on energy demand and emissions in Gauteng. Furthermore, based on a scenario analysis, recommendations were drawn with regard to future urban sprawl and emission mitigation measures. At the moment, there is no scientific research available which deals with the complex phenomenon of urban growth and its impact on energy and emissions in Gauteng. In the thesis, the change in land use patterns between 1991 and 2009 in Gauteng was analysed which confirms that the region is affected by urban sprawl. Furthermore, based on two scenarios, the future urban developments in the region till 2040 were simulated using a cellular automata model. The scenario analysis concludes that the outward expansion of Gauteng must be restricted within the existing urban boundary to stop further sprawl. In Gauteng, the residential sector is the third largest energy consumer and has the second largest share in greenhouse gas (GHG) emissions. Heavily coal-based electricity generation (around 93%), a high share of fossil fuels used by the households and use of inefficient energy technologies are the main reasons for high GHG emissions in the residential sector in Gauteng. Furthermore, the income disparity is also mirrored in the energy consumption patterns in Gauteng. Most of the poor households are struggling to gain access to electricity, whereas the rich communities are met with frequent power cuts. As the government tries to reduce the share of coal and other fossil fuels to achieve mitigation targets, reduction in energy consumption plays a major role in Gauteng. A comprehensive analysis based on various income groups and dwelling types was carried out to understand the energy consumption patterns in the residential sector. The scenario analysis also reveals how the share of different energy carriers used by households and their share in the final energy consumption affect the GHG emissions. The spatial distribution of the final energy demand in the residential sector helped in identifying energy intensive as well low energy demand areas in Gauteng. Energy intensive areas are located near the economically developed regions such as central business districts (CBD) in Johannesburg and Pretoria. The spatially explicit energy consumption could be a valuable tool for determining policies for implementing energy efficiency and renewable energy programs at the local level. Though the residential sector is not the highest energy consumer in Gauteng, the consumption and emissions in this sector can be easily influenced by the government by introducing various subsidies and incentives for renewable energy which would also help in minimising the high share of direct emissions by 2040. In addition, a thorough potential analysis for energy generation from woody biomass, energy crops, photovoltaic (rooftop and open space), solar water heaters and wind energy was carried out at the municipal and the provincial level which exhibits various possibilities to implement the use of renewable energy in the region. To sum up the thesis, the developed simulation model has been proven suitable to understand future urban patterns of a fast growing region like Gauteng. The simulated land use pattern would help in understanding what problems will occur in the future, as well as preparing the government to tackle these issues and develop new energy policies and strategies for Gauteng. Additionally, the spatial distribution of energy demand and renewable energy potential, which was assessed using a GIS-based model, helped in providing energy efficient and renewable energy-based solutions at the local level. It can be concluded that the constantly rising residential energy demand is not heavily influenced by the urban pattern and can only be reduced by increased use of efficient technologies and energy saving measures

Economic and environmental analysis of solar water heater utilisation in Gauteng Province, South Africa

This paper focuses on the energy economics and environmental impacts of solar water heaters (SWH) in the Gauteng Province and compares the results with other technology options for residential water heating with regard to the different income groups. The critical energy situation in South Africa and the highly coal dependent energy generation demonstrates the need to shift to a more sustainable way of living. The residential sector proves to be an optimal starting point to implement new technologies, especially for water heating. The residential hot water demand calculation shows that the annual demand in Gauteng is about 188 million cubic meters. In order to satisfy this demand, different technologies are investigated in this paper, where SWHs lie in focus. Due to the vast income inequality in Gauteng, and also in South Africa, it is obvious that there cannot be one single optimal solution suitable to all households. Therefore, this paper focuses on the differentiation of the residential sector into income groups to show the divergence in warm water demand and the applicability of alternative technologies. In order to analyse appropriate solutions for all income groups, low-cost alternatives are also analysed. The economic analysis shows that although SWHs have higher investment costs than conventional technologies, the payback periods are relatively short (between 3 and 4 years) for high and mid income groups. The payback periods will be even shorter when the planned electricity price tariff increase comes into effect. Furthermore, SWH utilisation has the additional effect of reducing the overall electricity demand up to 70% and greenhouse gas emissions significantly. In addition, SWHs are the most cost-effective water heating technology to reduce greenhouse gas emissions for mid and high income groups with negative abatement costs.It is concluded that the SWHs are the most suitable option to decrease fossil energy consumption and reduce the household’s expenditure for energy services, especially for mid and high income groups. For lower income groups the utilisation of solar energy can increase the access to energy services and living quality and, therewith, lessen the financial burden to meet their energy needs

Economic and environmental analysis of solar water heater utilisation in Gauteng Province, South Africa

This paper focuses on the energy economics and environmental impacts of solar water heaters (SWH) in the Gauteng Province and compares the results with other technology options for residential water heating with regard to the different income groups. The critical energy situation in South Africa and the highly coal dependent energy generation demonstrates the need to shift to a more sustainable way of living. The residential sector proves to be an optimal starting point to implement new technologies, especially for water heating. The residential hot water demand calculation shows that the annual demand in Gauteng is about 188 million cubic meters. In order to satisfy this demand, different technologies are investigated in this paper, where SWHs lie in focus. Due to the vast income inequality in Gauteng, and also in South Africa, it is obvious that there cannot be one single optimal solution suitable to all households. Therefore, this paper focuses on the differentiation of the residential sector into income groups to show the divergence in warm water demand and the applicability of alternative technologies. In order to analyse appropriate solutions for all income groups, low-cost alternatives are also analysed. The economic analysis shows that although SWHs have higher investment costs than conventional technologies, the payback periods are relatively short (between 3 and 4 years) for high and mid income groups. The payback periods will be even shorter when the planned electricity price tariff increase comes into effect. Furthermore, SWH utilisation has the additional effect of reducing the overall electricity demand up to 70% and greenhouse gas emissions significantly. In addition, SWHs are the most cost-effective water heating technology to reduce greenhouse gas emissions for mid and high income groups with negative abatement costs. It is concluded that the SWHs are the most suitable option to decrease fossil energy consumption and reduce the household’s expenditure for energy services, especially for mid and high income groups. For lower income groups the utilisation of solar energy can increase the access to energy services and living quality and, therewith, lessen the financial burden to meet their energy needs

Ecological Footprint: The Example of Gauteng Region

Since Wackernagel and Rees introduced the idea of the ecological footprint in 1992 [28, 21, 27], it has been established as a concept of measuring the sustainability of nations, regions, cities, individuals, industrial goods, etc. Today, the ecological footprint is seen as a measure of demand of natural resources with respect to the regeneration capacity of the Earth. Since the findings of Rees [21], quite sophisticated calculation procedures have been defined [15]. They are based on the generic idea that every impact on earth—which is a closed system—can be converted to an amount of biologically productive area. To allow comparability, they are expressed in global hectares (gha), which represent the average spatial productivity worldwide

Solar Energy Technologies – GHG Abatement Costs and Potentials for Gauteng, South Africa

This study presents an analysis of different technology measures for reducing greenhouse gas (GHG) emissions in different energy sectors (i.e., electricity generation, residential appliances, transport) of a metropolitan region, using the example of Gauteng, South Africa. This analysis serves to identify measures with a high reduction potential and low abatement costs and compare them with other promising renewable energy technologies. The study takes the urban region of Gauteng, South Africa, the most densely urbanised area in South Africa, as a regional example. The resulting ‘marginal abatement cost curve (MACC)’ – also known as ‘greenhouse gas mitigation cost and potential curve’ – can be used for any given energy system to rank and prioritise measures and technology implementations according to their economic and environmental impacts for greenhouse gas mitigation. This work does not only serve the urban region of Gauteng, but can also be transferred to any other city or region, as they are confronted with similar questions to identify the highest reduction potentials and the most efficient reduction measures for mitigating CO2 emissions in different sectors as efficiently as possible. Nevertheless, the potentials, costs, and emission profiles have to be thoroughly assessed for each individual technology separately