University of South Wales Master of Sciences Thesis
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Introduction The rapidly increasing costs of fossil fuel and power line extensions, combined with the desire to reduce carbon dioxide emissions pushed the development of hybrid power system suited for remote locations. Hybrid power systems are designed for the generation and use of electrical power. They are independent of a large, centralized electricity grid and incorporate more than one type of power source. They may range in size from relatively large island grids to individual household power supplies. Especially for remote places where electricity has not reached yet it is recommended that decentralized generation, which is based on renewable energy technologies, is perhaps the only efficient way to provide electricity. For the same reasons that make difficulty of extending the conventional grids, transporting fuel to the remote areas and replacement parts needed for the conventional sources like diesel generators. The energy for Renewable energy sources (RES) is locally available and a properly chosen RESs can reduce the operating periods of the conventional power sources considerably which will result in reduction of the fuel consumption and minimizing the need of maintenance. This in turn will result in the improvement of sustainable power generation. A system, which depends entirely upon RESs, is possible but not reliable for the uninsured availability of the resources for the RES systems. In order to meet the sustained load demands during the varying natural conditions, different renewable energy sources are integrated for extended usage of alternative energy, However, a lot of requirements have to be considered first. It is important to understand all the factors that influence its behavior, in order to get the best of it. The most important factors are location, time and user needs (power). Location associates information about climate, energy sources availability and environment conditions. This information is very important to decide what kind of renewable generators can be chosen [1]. This thesis focuses on the combination of wind, solar, Genset and energy storing systems for sustainable power generation. The wind turbine output power varies with the wind speed at different conditions. The solar energy also varies with the hourly, daily and seasonal variation of solar irradiation. Thus, a generator-set system with a battery bank (energy storage bank) can be integrated with the wind turbine(s) and PV-system to ensure that the system performs under all conditions. In the proposed system, when the wind speed and solar irradiation is insufficient to meet the demand and whenever there is excess supply from the RESs, the energy storage bank stores energy, which will be used at times when there are insufficient supplies from the RESs. If either the available power from the wind turbine or from the solar panels cannot satisfy the load demand, the Genset system can meet the excess power demand. Aims A combination of different renewable energy sources, like wind generator and PV-system, with conventional energy source, like a diesel generator, is known as hybrid power system. Hybrid systems can provide a steady community-level electricity service, such as village electrification, offering also the possibility to be upgraded through grid connection in the future. The advantages of using renewable energy sources for generating power in remote islands are obvious such as the cost of transported fuel are often prohibitive fossil fuel and that there is increasing concern on the issues of climate change and global warming. |