I suspect it being evening peak made it worse, because that's peak time, so I think in normal operation they're discharging some of the batteries/pump storage t

I suspect it being evening peak made it worse, because that's peak time, so I think in normal operation they're discharging some of the batteries/pump storage that's taken up some of the spare capacity during the day. I would encourage more people to read the actual interim report - it's quite detailed with lots of detail about the frequency measurement and trips.