School of Architecture and Planning

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Browsing School of Architecture and Planning by Faculty "Faculty of Engineering and the Built Environment"

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    Assessing the energy performance gap between 6-star and net-zero energy buildings for South Africa
    (2022) Analo, Andrew
    Energy efficiency in buildings has been systematically coupled with the green-rating of buildings based on systems such as the Star-rating of the Green Building Council of South Africa (GBCSA). Net-zero energy buildings (NZEBs) have also been receiving increased attention as a way of addressing concerns over depleting energy resources (especially for fossil fuels), increasing energy-costs and greenhouse gas (GHG) emissions which contribute to global warming and climate change. With a focus on reduction in contribution to GHG-emissions and thus enhancing climate change mitigation of 6-Star green-rated buildings the study applied a case-study approach based on energy performance of the Department of Environmental Affairs (DEA) Building in Pretoria. Secondary data show that the building’s status quo energy performance is 112kWh/m2/yr. Within the temperate-interior climatic zone for Pretoria (as per energy efficiency regulations for buildings in South Africa), psychrometric chart analysis showed that the building could achieve a higherlevel of thermal comfort through further optimization of passive design interventions. Edge-tool simulation results on full optimization of passive design and energy efficiency interventions indicate that a net-zero energy building (NZEB) performance of the same sized building could achieve an energy performance level of 45kWh/m2/yr, thus revealing an energy performance gap of 67kWh/m2/yr. This translates to 60% savings compared to the status quo 6-Star performance of 3076 291kWh/year. Assessment of roof-area for solar PV system indicated that it is adequate for the energy balance towards a NZEB. Assessment of simple payback period per intervention indicates less than one-year payback period for tenant lighting while tenant equipment indicatesa payback period of just over a year and PV-installation at three-years. The findings indicate that the intervention-costs for migration to NZEB fall within the acceptable range for South African investors (maximum of 3 to 5 years). The above findings indicate that the pursuit of NZEBs would significantly contribute towards mitigation of GHG-emissions and climate change and thus calls for further exploration of pathways towards mandatory NZEBs for South Africa.
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    Smart grid and net metering for grid-interactive distributed generation for the City of Ekurhuleni
    (2022) Phiri, Alfred
    Increased frequency of electricity outages due to load-shedding coupled with escalating tariffs is forcing customers of municipal electricity utilities to venture into Distributed Generation (DG) technologies. These trends pose major infrastructure-reliability and revenue-erosion risks for municipal utilities which further impair quality of service to their customers, mainly as a result of dilapidated grid-infrastructure which contributes to escalation in distribution losses. With City of Ekurhuleni (CoE) as a case study, the research applied a qualitative approach to investigate the relevance of smart grid and net-metering systems as a response mechanism towards promotion of DG while also facilitating operational viability of the municipal utility. Primary data collected through interviews with electricity-sector experts as well secondary data from diverse sources were used to derive the key findings and conclusions of the study. Experiences from other countries such as Germany show that smart grids have also been pivotal towards harnessing renewable energy through DG and would therefore be critical towards addressing the prevailing distribution grid challenges within municipal authorities. In contrast, study findings indicate a steady increase in DG installations within CoE as commercial and industrial customers pursue their goal of energy security at lower costs. However, the utility has not effectively transformed the DG opportunity to cheaper electricity due to inhibitive regulatory and policy framework which also raises the risk of revenue erosion posed by DG. In particular, the overall findings support the working hypothesis which suggest that upgrading grid infrastructure and introduction of a responsive tariff-scheme is key to incentivise the adoption of grid-interactive DG within its jurisdiction. Given the qualitative focus of the study on smart grids and net metering, one of the key recommendations would be political mobilisation across all departments in CoE to provide input towards solving prevailing grid challenges and as well as evolving a responsive business model to facilitate transparent participation of small-scale generators through DG.