The design of overhead transmission lines must take into account the maximum ambient temperature that determines conductor sag (and therefore pole/line height requirements). – AGL found that savings can be made in the design of overhead transmission lines.
Report extract
The design of overhead transmission lines must take into account the maximum ambient temperature that determines conductor sag (and therefore pole/line height requirements). Transmission lines are also designed to take into account maximum expected current (in this case, the current generated by the solar plant).
While it would be reasonable to assume that peak solar plant output would occur during periods of high solar radiation (which would imply high ambient temperatures), due to the thermal de rating of photovoltaic (PV) modules with temperature, it is unlikely that the peak output of a solar plant will occur at the same time as the maximum ambient temperature. As a result, overhead transmission lines may not need to be designed for the condition in which peak plant output and maximum ambient temperature occurs at the same time.