Selection method of statistical duration in solar radiation model based on climate abrupt change year

Abstract:

Establishing a solar radiation model which employs pertinent meteorological parameters for the estimation of solar radiation is essential for enhancing solar radiation data. The statistical duration used by the radiation model influences the model’s coefficients and further affects its estimation errors. To select a proper statistics duration and minimize the radiation model estimation error, this paper proposes a kind of method that chooses an appropriate statistical duration based on the climate abrupt change year. By analyzing the meteorological and radiation data records of more than 25 years from 90 observatories and meteorological stations in China, three meteorological elements that are closely related to solar radiation, namely, sunshine duration, temperature and humidity, are used for abrupt change inspection. The coefficient of variation method is used to determine the climate abrupt change year. Daily global radiation model and daily diffuse radiation model are established respectively by choosing the statistics duration of observation data for over 25 years and the statistics duration after climate abrupt change year. The estimation errors of different models using different statistics duration are compared. According to the error results, the Root Mean Square Error percentage can be reduced by above 2% if data record years after the climate abrupt change year, which serves as the time node, are used as the modeling statistics duration. It demonstrates that the method of choosing radiation modeling duration using climate abrupt change year can reduce the modeling estimation error effectively. The method provides a reference to select the statistical duration in radiation models.