Halloween: Severe weather not solar flare caused power cuts
The lights went out across parts of south Wales on Sunday night during Halloween.
On social media there was speculation it was caused by a solar flare - but National Grid said it was caused by a voltage drop due to severe weather.
South Wales Fire and Rescue Service said it triggered alarm systems and Cardiff and Vale health board said a power cut briefly affected its mass vaccination centre in Cardiff Bay.
It happened at about 18:00 GMT on Sunday during heavy showers and strong winds.
A spokesman for the National Grid Group confirmed the fault had been traced to a large substation on the outskirts of Newport.
The Whitson substation carries high voltage circuits and is connected to the substations at Seabank in Bristol and Iron Acton in south Gloucestershire.
