DESIGN AND PERFORMANCE EVALUATION OF
RENEWABLE ENERGY BASED MICRO-GRID
SYSTEM WITH ENERGY STORAGE
main objective of this thesis is to evaluate the technical and economic performance of a micro grid (MG) comparing between two modes of MG operation; stand-alone (off- grid), and grid connected operation (on-grid). The Micro- Grid System (MGS) suggested components are; PV panels, wind turbine(s) inverter, and control unit in case of grid connected. In the stand alone mode diesel generator and short term storage are added to the renewable generators. To investigate the performance of the MGS; technically, detailed models for each component will be presented then the complete MGS model is developed. Another objective is to investigate which is the more suitable type of short term storage to be included in the MGS; batteries or super-capacitors. The third objective is the economical evaluation of MGS comparing the system net present cost (NPC) and cost of generated electricity for the two modes of operation; on-grid and off-grid. To evaluate electrical energy storage in batteries and compare it with advanced super-capacitor technology, an experimental set up is designed and constructed. A set of experiments were conducted to investigate the different characteristics and their suitability to charging and discharging conditions. The results showed that super capacitor has higher power density than battery, while battery surpasses the super capacitor in energy density. Hence, the results confirm the understanding that super-capacitor is more suitable for rapid charging and discharging processes than battery which is more suitable for long charging and discharging times. Also, from the economic point of view battery is still more economical than super capacitors.