Effects of global warming on transmission line sag

Abstract

Global warming has forced the power industry to adapt its infrastructure and develop technology in order to mitigate the effects and reduce the extent to which it will affect the operation of the electrical grid. With this goal in mind, the project attempts to quantify the effect of global warming on transmission line sag. First, a climate model that could predict temperature data for the time period (2001-2100) was needed. Next, a relationship between temperature and electricity demand needed to be quantified. Using this relationship and the temperature values generated by the climate model, the predicted electricity demand values were calculated for the examined time period. Since the voltage at which power is transported remains constant, the rate at which power is delivered will be given by the current flowing through the conductor. Using the estimated current values, the temperature of the conductor was calculated. This value is then used to calculate incremental sag due to the additional electrical demand. The calculated incremental sag is then plotted across time to show the increase in sag as temperatures increase. The plots also show various spikes in transmission line sag values ranging from less than an inch to just over two inches over the examined time period which does not significantly affect the operation of the grid. However, the project was performed using ideal values and is only a best case scenario. Overall, the project was successful in establishing that a relationship between global warming and transmission sag does exist, and that it needs to be addressed during future infrastructure planning.