For most of this evening, the one incandescent uplighter in our sitting room was really dim. All the LEDs and CFLs were as bright as usual, but I expect they were taking more current to compensate. Two of them were very reluctant to come on. I suspect the voltage was very low. I would have got a meter out and checked but as we had visitors I didn't think it appropriate. At about 9:30 everything suddenly went back to normal.

Anyone know what was going on?

super moon

Unfortunately Scottish Power provide the worst interface of the electricity companies to see problems (most have maps), you could try putting your postcode in HERE

Might as well have been the super moon

"There was a fault which has been resolved"

Very informative!