Performance evaluation of solar tracking photovoltaic systems operating in Canada

摘要

In 2011, the total installed PV capacity in Canada was almost 289 MW and it could reach between 9 and 15 GW by 2025. According to previous studies, sun tracking PV systems can capture 20% to 50% more solar radiation than fixed systems. Solar tracker is a device that keeps PV panels perpendicular to the sun rays. There is a lack of knowledge about the performance of sun tracking PV systems operating under weather conditions of Canada.ududThree principal objectives were defined for this research. The first objective is the performance evaluation of various configurations (fixed and tracking) of PV systems. This objective is achieved by simulation and analysis of four orientations of PV systems: horizontal, inclined, single-axis tracking, and dual-axis tracking systems. These systems are analysed in yearly and daily periods. Four cities with different typical weather conditions have been studied: Montreal (Canada), Casablanca (Morocco), Ouagadougou (Burkina Faso), and Olympia (U.S.A). The results from simulations show that the dual-axis tracking PV systems have the best performance in all selected locations.ududThe second objective is the investigation of environmental effects on the performance of PV systems. This objective is achieved by studying the ambient temperature and reflected radiation from the snow (albedo effect) influences. Reflected radiation from the snow accumulated on the ground causes an increase in arrays irradiation up to 4.1%, 5.6%, and 6.9% for tilted, single-axis tracking, and dual-axis tracking systems over the winter, respectively.ududThe final objective of this thesis is developing the optimum tracking method for Canada. This objective is achieved by analyzing various orientations of PV systems in some typical days: a clear winter day, a clear summer day, an overcast day for both winter and summer, and calculation of tracking advantage during these days.ududAccording to the daily analyses, tracking the sun is effective in clear days and unnecessary in overcast days. These results are supported by previous researches. Our results allow proposing a method that tracks the sun in clear conditions and go to horizontal position in overcast conditions. In partially cloudy conditions, depending on the clearness index and reflected radiation from the ground, tracking the sun could be effective or counterproductive. Furthermore, going to horizontal position consumes energy. If the reflected radiation from the snow is considerable, the PV system should stay in final position as it doesn’t consume any energy.