摘要： The increasing growth of solar power plants installation necessitates performing accurate investigations on new methods to find optimum tilt angel and orientation of photovoltaic (PV) panels. Using optimum methods increases collected solar irradiance, and consequently, maximize the expected annual harvested energy, which means better financial performance of PV power plants. In this paper, the optimum tilt angle and orientation of PV panels are calculated by introducing two accurate analytic methods, which take into account the climate conditions of the installation region by considering wind speed, irradiance and ambient temperature. The results of this paper, which are supported by Monte Carlo simulation, indicate that compared with the traditional method, an increase in expected annual produced energy of solar panels is achievable using the optimum tilt angel and orientation calculated by the presented methods.