This is what I received from Ukpowernet. As of 05:16 here is a summary of the issue - We became aware of the fault at 04:44. The cause is a fault with an underground cable in the Dulwich SE22 area, our engineers were on their way to site at 04:50. The current status of the issue is that we've assigned engineers to locate and fix the issue; they are now on their way, the estimated timeframe to have power back on is 06:30 to 07:30. We'll be in touch when we have more information.