Optimum Tilt Angle and the Corresponding Uncertainty for an Inclined Solar Collector

Determination of the optimum slope angle of a solar collector is highly dependent on the incident solar radiations on the collector surface. As collectedinstantaneous data of incident solar radiation values are averaged, more attention must be directed towards these figures by determining the uncertainties in thesemeasurements as this allows the calculation of the optimum slope angle. These average solar radiations give a definite optimum slope angle if they come alongwith the lowest uncertainties. Hence, this study aimed to find the optimum slope angles of solar collectors withcorresponding uncertainties. For doing this, the solar radiation data borrowed from the Iranian Metrological Organization (IMO) which were measured on ahorizontal surface in a period of twenty years (1986- 2005), were employed. The results showed that the uncertainties of the optimum slope angles in some citieswere quite high and it indicated that in this case more attention should be paid to select the appropriate optimum slope angle. These changes were more in coldregions compared to hot and dry regions because, the weather in the colder climates is typically more transientthan the weather in hot and dry climates.

کلیدواژه ها:

Tilt angle ، Solar collectors ، Solar radiation ، Uncertainty