Lovely Weather We’re Having.

Climate change is never far from the minds of anyone working in and around the power section today. Electrical grids across the world are beginning to be adapted to an ever increasing diversity of fuel types, and of generator sizes, with a large focus on renewables, as the UK and other countries seek to significantly lower their carbon emissions. However, climate change may have another, more direct, impact on these grids. One significant consequence of rising global temperatures is likely to be a change in weather patterns, with the potential for more frequent significant weather events (such as lightning storms and blizzards), or for these events to be more extreme when they do happen (or both).

On the GB grid around half of all transmission level faults, are caused in some manner by the weather, so an increase in weather events, or extremes, could lead to a significant increase in the number, and impact, of these faults, which could noticeably reduce the stability of the electricity supply.

One project in the CDT that began to address this potential problem, was to look at the extent to which individual weather-related fault events on the GB transmission network were related. Faults which occurred in the ScottishPower Energy Networks (SPEN) transmission license area between 1985-2011 were grouped based on the likelihood of them being caused by the same weather event, based on their proximity and the time at which they occurred.

The main types of fault-causing weather that were identified in the data were: snow, sleet, ice, and blizzard; wind, gales, and windborne objects; salt, corrosion, and condensation, and lightning. Of these, the wind-type had the greatest impact, and occurred most often, the snow-type occurred less, but had a significant impact, the lightning-type occurred often, but did not have a large impact, and the pollution-type were infrequent and low-impact.

From this information, it was possible to make a qualitative assessment on various future weather scenarios, based on how they might impact the overall stability of the grid. Lightning is likely to increase as temperatures rise, while snow and blizzards are likely to decrease, which would give an overall decrease in the number of transmission fault events. However, the impact of climate change on the wind is not currently known. If average wind speeds increase in the coming years, there could be a large increase in transmission faults.

Similar work looking at the impact of the weather on transmission faults in Norway and Iceland, has come to similar conclusions. Transmission network operators, therefore, must be prepared for the additional challenges of a changing global climate, beyond merely carbon-reduction.

Euan Morris MEng

This project entitled “Spatial and Temporal Clustering of Fault Events on the GB Transmission Network” was presented at the Probabilistic Methods Applied to Power Systems conference in October 2016 held in Beijing, PR China.