How does Britain keep the lights on and connections live during extreme weather events? In the wake of 2025’s first major storm, we take a closer look at resilience in the power network.
Storm-related outages are common. We only have to think back a few weeks to Storm Darragh to see that. But what lies at the heart of why the UK Grid remains so resilient? The answer is permanent monitoring equipment which can detect pre-faults, their location, and assist network operators in proactive repair work.
A pre-fault is a short-duration spike in current caused by a breakdown of insulation on the feeder, with the current returning to a normal level afterwards. A fault, however, is a higher energy event where the fault current persists until protection operates to clear it, which results in an interruption to the customer supply.
Faults can be caused by numerous things such as insulation breakdown, third-party damage, thermo-mechanical effects, and moisture ingress – which is a key risk during adverse weather.
When we think of rainfall and storms impacting electricity networks, we envision lightning strikes and heavy gales bringing down power lines and pylons, but damage is also done underground. Heavy rainfall that settles in one spot filters through the ground and into the electricity lines below, causing faults and outages in the network and the substations that feed homes and businesses.
Rainfall and precipitation in the UK, on average, can be as high as 130mm per month in the winter and between 70mm-90mm in the summer. In addition to heavy rainfall, storms introduce more volatile and challenging weather to the country’s electricity networks.
When storm Babet, hit the UK in October 2023, our fleet of 19,000+ VisNet Hubs and Guard devices saw over 10,000 pre-fault events across 24 hours, indicating widespread electrical disturbance. These events indicate damage to underground cables, inevitably leading to future outages.
To prevent pre-faults from becoming full faults that lead to customer outages, you must locate the pre-fault to perform repair or restoration work. To do this efficiently, waveform-capable monitoring equipment such as the VisNet Hub and the reliability app suite must be installed.
Adverse weather is unavoidable in the UK, meaning electricity networks and lines will always be vulnerable. A complete monitoring system will allow you to take a proactive approach to pre-faults, reducing the number of customer outages and increasing the quality of your service. Outages result in costly penalties and complaints, and repair work on full faults is more expensive than proactive work on a pre-fault.
Electricity networks frequently prevent outages from storm-related faults – sometimes as many as 100-200 per day. However, according to VisNet, from EA Technology, the low voltage asset management solutions provider, you would never notice it.
Dr David Clements is Data Analytics Manager at low voltage asset management solutions provider VisNet from EA Technology.
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Image: Rose Galloway Green via Unsplash