Davidson, Innocent Ewean.Khan, Shiraz Yusuf.2019-02-182019-02-1820152015http://hdl.handle.net/10413/16145Master of Science in Power and Energy Systems. University of KwaZulu-Natal, Durban, 2015.Underground Pumped Hydroelectric Energy Storage (UGPHES) is a similar energy storage concept to the conventional Pumped Hydroelectric Energy Storage (PHES) with the major difference being that the lower reservoir is in an underground cavern system. Electricity is stored in the form of gravitational potential energy between a surface reservoir and an underlying subterranean reservoir. In this study, various existing energy storage systems are examined with the UGPHES introduced as an alternative technology for bulk energy storage in South Africa to contribute to the constrained electricity network with environmental and economic benefits. The use of existing infrastructure for the implementation of UGPHES systems is explored, which includes the use of aquifers and abandoned mines. South Africa has large amounts of groundwater as well as transboundary aquifers which may be used for UGPHES systems. A mathematical model is presented which highlights the considerations for the implementation of an aquifer UGPHES system including head and aquifer transmissivity. The use of abandoned mines in South Africa is also explored as it presents an existing underground cavern as well as large amounts of groundwater. Finally, a mathematical model is presented to provide an analysis of the water hammer phenomenon as well as an economic analysis for the use of abandoned mines for UGPHES systems.en-ZAHeat storage.Energy storage--South Africa.Pumped storage power plants--South Africa.Theses--Electric power and energy systems.Energy storage.Pumped storage power plants.Underground Pumped Hydroelectric Energy Storage.Pumped Hydroelectric Energy Storage (PHES).Thesis