Date of Award
Doctor of Philosophy (PhD)
This dissertation presents advanced methods that could be used to assess various impact of climate change to hydropower and reliability assessment of wind resource using alternative reservoir operation that maximizes the firm generation of integrated wind and hydropower. The first component of this study introduces a hybrid approach of risk based climate change impact assessment. This method combines uncertainties in historical climate variability with uncertainties in climate predictions to conduct more comprehensive climate change impact assessment on hydropower. Results from this study, illustrated in Zambezi and Congo River basins, indicate that the single basecase approach of delta-change technique substantially underestimates the potential impact of climate change. Particularly, assessments for water resource systems in areas with high natural hydroclimatic variability the combined effect natural variability and climate change is more pronounced.
The second component utilizes the concept of Empirical Orthogonal Functions (EOFs) analysis technique to access the join spatio-temporal patterns of interannual variability hydropower generation between different power pools in Africa. EOF analysis of annual streamflow and hydropower generation was carried out followed by investigation of the resulting dominant spatial patterns to identify locations of existing and future potential hydropower sites which indicate a homogeneous or a heterogeneous pattern of variability. Results indicated a distinct out-of-phase pattern of variability between Southern and West African Power pools. Furthermore, the method was extended to conducted potential impact of climate change induced change in inter-annual variability.
The third component presents a reliability assessment method of wind-hydropower integration. A water resources model combined with a single node power grid system model accompanied by a genetic algorithm solver is implemented to determine optimum operation strategy for each storage reservoir aiming at maximizing the 90th percentile power generation over the entire simulation period. This model is tested on the hydropower system in the Zambezi basin to demonstrate how storage reservoirs could be used to offset wind power intermittence in South Africa. Results show an increased level of wind penetration, a reduced level of coal power utilization and less cycling requirement in power system as a result of better regulation that is achieved through the combined operation.
Gebretsadik, Yohannes Daniel, "The Impact of Climate Change and Variability on Africa's Renewable Energy Development :A Hybrid Uncertainty Approach" (2013). Civil Engineering Graduate Theses & Dissertations. 447.