Storm Arwen Report

Reports, plans and updates

Publication date

Industry sector

Distribution Network

Storm Arwen brought widespread disruption to the UK and resulted in over one million customers losing power. Approximately 40,000 customers were without supply for more than three days, and nearly 4,000 customers were off supply for over a week. In light of the severity of the event and the long duration that many customers endured without power, we have conducted a review of the DNOs response to Storm Arwen.

We published an interim report in February 2022 and provided an early indication of the areas that needed to be investigated further. We recognised that staff in all DNOs worked hard in challenging circumstances to get customers reconnected but found that there are clear lessons to be learned to improve DNO performance.  This final report builds upon on the initial findings we outlined in our interim report and sets out clear recommendations for improvement.

The final report has been published today.

In this report we have set out findings of our review and identified a clear package of recommendations.

Final report Recommendations:

  • Alternative action package – An additional £10.28 million alternative action package from NPg, SSEN and ENWL was agreed upon for consumers.
  • Network Resilience – We found that the majority of network faults were caused by strong winds or trees and branches falling onto power lines. We have recommended four actions to improve network resilience and the speed of customer reconnections.
  • Planning and Preparation – Emergency plans not sufficient to deal with the scale of the storm and some DNOs did not adapt their resources or strategies quickly enough. We have recommended that DNOs submit winter preparedness plans to Ofgem to provide assurance that all necessary steps have been taken.
  • Handling of Incidents – limited monitoring on the lower voltage networks, hindered the DNOs from understanding the full scale and complexity of faults. This impacted the resources they initially deployed to undertake repairs, restore power, and support customers. We have made three recommendations to improve the identification of faults and the deployment of generators.
  • Communication and Support – There were issues with the availability of phone lines, websites and how efficient customer enquiries were dealt with. We have made four recommendations to improve the handling of large call volumes, website traffic, reporting metrics of comms channels and customer service for call-backs. We have provided a recommendation for DNOs improve how they estimate restoration times, work with local resilience partners and making clear to customers what support (e.g. hot meals, accommodation) is available to them. 
  • Support after the Incident – Ofgem believes that some DNOs were too slow in paying out compensation. We have made four recommendations to improve how DNOs obtain customer data and develop more robust payment mechanisms to deliver compensation at scale.

Severe weather events are likely to become more common, as the effects of the climate change are felt, so it is imperative that all DNOs are well prepared. All DNOs have areas for improvement, and it will require coordination and collaboration amongst them to implement the recommendations effectively. This is an opportunity that the DNOs must seize and show improved performance in future severe weather events.

We will continue to use all the tools in our regulatory toolkit to hold DNOs to account in delivering for their customers.