Estimation of hourly solar irradiance and its implication on building energy efficiency

Over time there has been a growing demand for solar irradiance data, especially for titled or vertical surfaces. Such demands have sprung up from the necessity of using such data for evaluating active systems, determining building heating and cooling loads and designing energy-efficient buildings. Long term measurement is the most effective method for obtaining solar irradiance data, but few measuring stations provide this data. An alternative approach is the development of solar radiation models through the correlation of available meteorological data. Thus, this study presents results from the statistical analysis of modelled hourly solar irradiance in Hong Kong. The implication of the findings on building cooling load and photovoltaic system designs are discussed.