Modeling of solar PV- wind hybrid generation system and optimization of battery energy storage system for rural electrification in Makambako, Njombe region, Tanzania

Recently, it is desirable to use a clean and abundant energy source for power generation. Renewable energy sources (RESs) such as solar PV and wind being an impeccable choice. However, difficulty in power extraction from these RESs is experienced due to dynamic fluctuation in weather parameters, in addition, using solar PV-wind power generation in stand-alone mode, larger storage devices would be needed for compensation of their fluctuating nature; which would make the overall system more expensive. Hence, a choice of hybrid system is inevitable in order to enhance reliability and reduce the energy storage system (ESS) requirements. Moreover, to effectively reduce the cost of the system, an optimization process on the battery ESS needs to be carried out. This dissertation proposed a hybrid solar PV-wind power generation system and optimization method for the battery ESS and validated the viability of this option for rural electrification. The Mixed Integer Linear Programming (MILP) optimization strategy is used in order to obtain a minimum battery ESS investment cost that consecutively reduced the cost of the entire system. The proposed hybrid solar PV-wind system has been implemented in MATLAB/Simulink software. On testing the performance of the system, it is observed that the voltage and frequency at the Point of Common Coupling (PCC) is maintained constant at 1 pu and 50 Hz, respectively. Also, on optimizing the battery ESS, its investment cost is reduced by about 80% and that of the entire system reduced by 2.5%.