Nanogrid For Renewable Off-GridSystem : Nanogrid For Renewable Off-GridSystem

Sammanfattning: Power grids utilize large central generating stations which entails the use of long transmission lines to deliver power to consumers. This approach poses some challenges such as line loses and carbon dioxide (CO2) emission into the environment from the burning of fossil fuels from such large generators. There is also little or no availability of electricity in the rural and isolated areas where the supply of power from the national grid may be considered uneconomical. Distributed generation proffers solutions to these challenges by generating power close to the point of consumption. A nanogrid is an important aspect of distributed generation in which electricity is generated for a single building. Nanogrids usually employ renewable sources of power such as solar and wind energy to generate electricity. Hence, reducing carbon dioxide emission. Also due to the versatility of nanogrids, people in the rural areas can generate their own electricity. However, the intermittent supply of power due to the variations of wind speed during the entire course of a day poses a major challenge in the use of nanogrids. This thesis focuses on the study of the interaction of the savonius wind turbine in an existing nanogrid with a particular load so as to have a better understanding of how the wind turbine parameters such as the wind speed and Tip Speed Ratio can affect the power generated from the turbine.This is achieved by modelling and measuring the power absorption of the savonius wind turbine operating in the nanogrid. From the results obtained in this project, it is glaring that the wind speed and Tip Speed Ratio of the wind turbine play a vital role in the total power harvested from the turbine. If the rotor blades spin too slowly, the wind will pass through the gap between the blades and no power will be generated. Whereas when the blades spin too fast, they act like a shield against the wind speed, creating turbulence in the air as they spin and so when the incoming blade arrives too fast, it hits the turbulent air created by the blade before it and thus, no power will also be generated in this situation. Therefore, it is of utmost importance to design the wind turbine with an optimal Tip Speed Ratio to obtain maximum power from the turbine and thus, improve the reliability and efficiency of the nanogrid technology.