Last night at around 4am there was a power cut for c.20 mins. Does anyone know what happened or if this was a planned outage? From what I could see from the window, it was roughly between Honor Oak Park parade, Brockley Rise and Stanstead Road

If it was planned it would have probably been during daylight hours, not at 4 am.
I reckon it was only for 4 or 5 minutes.
Perhaps something to do with the very high winds last night?

A tree came down on the railway line to Catford. Perhaps it brought down a power cable.

Ah, that sounds like it may well be the reason, thanks. All back to normal now. I had a bout of insomnia and was staring out of the window, when suddenly all the lights went off outside. For a minute there, I thought I had magic powers.