Electric dominoes?

Last week, the Committee on Climate Change published its latest report on the evidence of risks (and opportunities) to UK infrastructure from a changing climate, and warned that climate change could have a domino effect on key infrastructure – that failure in one part could affect others.

Specifically they highlighted the example of where local electricity supplies are carried across rivers attached to a road bridge, and if the bridge is swept away in a flood… well, you get the picture.

So how resilient is the electricity system in the UK?

Three recent research projects funded by the EPSRC have been looking at the resilience of the UK electricity system from generation through to local distribution. Their findings describe a system that is more resilient in some parts than others, but that as a whole, the system is quite robust to both sea level rise and the likely weather of the future.

The ARCoES project is looking at the generation system and specifically at some of the large coastal nuclear power sites and their vulnerability to long term sea level rise and to storm-driven surges. The project has identified the main processes that drive sea level rise and storm risks, and how these interact with other coastal processes such as coastal development, local defences and changes in sediment flows. This has resulted in the development of a Flood Hazard Rating and also highlighted the range of decision support tools that are available to help determine optimum investment in defences and to identify where coastal conditions may be suitable for new energy infrastructure.

The project also applied their approach to some of the original sites chosen for the coastal plants as long ago as the 1950s. The modelling showed that they had been really well selected and were resilient to both long term sea level rise and to storm surge – so the engineers back in the day had done a really good job without the benefit of computers or our current knowledge of climate change risks!

The other two projects, RESNET and ARIES, looked at the high voltage transmission system and the more local distribution systems respectively. The projects explored the duel challenges of ensuring a reliable electricity supply system while at the same time reducing carbon emissions.

The increase in low carbon forms of electricity supply and the shift to renewables will alter the way in which the grid needs to be designed and operated. But this seems to be manageable provided that proper long term planning is in place – the new modelling approaches developed by these two EPSRC projects can help with this.

Changes in weather patterns will cause some new challenges to this planning. In particular, higher temperatures will result in a reduction in capacity in parts of the system, such as cables and transformers, that are unable to carry as much power as the heat increases. This will be exacerbated by the increase in demand for cooling as summer temperatures rise, and as a result the peak energy demand is likely to move from the winter, as it is at present, to the summer.

However, much of the physical infrastructure – the pylons and sub-stations – are pretty robust particularly at the national transmission scale. Local distribution, where power is transmitted at lower voltage, often on wooden poles, will remain vulnerable to local storms – particularly due to falling trees – but these will not have any significant impact on the national system, but will continue to have localised impacts.

The final challenge identified for the industry as a whole is how to consider resilience at multiple scales to ensure that the differing needs of different consumer groups are reflected in planning, and the fact that large industrial consumers, critical users (e.g. hospitals) and private consumers all have different needs and priorities. Allied to this is an opportunity for the industry to provide additional help to users by making appropriate advice available for differing consumers and consumer groups as to the types of measures that they can take to enhance their own resilience.

With the system showing a robustness to both sea level rise and the impacts of a changing climate, perhaps the biggest challenge is how the system responds from the need to de-carbonise on both the demand and supply side.

So is the UK’s electricity system a part of a national game of dominoes where a failure in one place is like to make it all fall over? No – the research suggests not. No electric dominoes here, but certainly always ongoing opportunities at the local level to be more prepared.

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