Quality control of solar radiation data: Present status and proposed new approaches

During the past few decades, there has been a continual rise in interest in passive and active solar energy uses, not only in the governmental and commercial sectors, but also within the private sector. There is thus a need for taking measurements of solar irradiation and creating local and regional databases of irradiation and synoptic (meteorological) information. However, there is no guarantee of the quality of the data collected, as often due care is not exercised with respect to quality control of the measured dataset. This article reviews the presently available procedures for quality assessment of the solar irradiation data. Furthermore, we propose a set of stringent physical and statistical measures to create a semi-automated procedure that is based on the creation of an envelope in the clearness index-diffuse to global irradiance ratio domain. The procedure is very general in nature and may be used with equal effectiveness for any terrestrial dataset