
Development: Design considerations of photovoltaic systems 159
In addition, there is no standard to determine the ambient temperature, T, to use
in equation (1). It is common practice to observe historical meteorological data and
based on this information, select one of the lowest values in the trend. It is important
to note that this temperature value should be selected at sunrise, where the lowest
temperature during daylight hours is likely to happen and when the cell and ambient
temperature are the closest. The selection of this temperature tends to be made con-
servatively, which further accentuates the already biased effect of using the ...