Here's a snapshot of grid frequency over the past week - the operational limits have been breached in both directions over the week Both yesterday and today saw swings between exceeding the upper and lower limits within relatively short periods - today was the most dramatic with a jump above 50.2 Hz, a couple of short drops below 49.8 Hz and then a larger jump above 50.2 Hz in the space of 90 minutes Friday saw frequency below the operational limit for 9 continuous minutes falling to a low of 49.75 Hz, resolved with Emergency Assistance on the interconnectors while today saw 2.5 minutes above 50.2 Hz rising to a high of 50.278 Hz Also shown are interconnector flows and SO-SO trades with the times when the intraday limits were breached highlighted - yesterday NESO traded against the flow for 14 consecutive settlement periods (7 hours) with several hours at 2700 MW (vs limit of 1500 MW) Finally we can see the de-rated margin and loss of load probability for the past week. The margin was healthy at all times and the LOLP was always zero So, in a well supplied market, NESO has struggled to keep the frequency inside the operational limit and has breached intraday interconnector trading limits multiple times, and extensively yesterday Not shown here are the EA on Friday and the two large EAs on Monday of 500 MW and 1200 MW. Also not shown are the balancing costs - yesterday was close to £50m which is the highest day ever. Today is £23.44m so far - the daily average is £2.3m. September was a record month and October is on track to be worse This is not evidence of a system operating securely. It's evidence of a system that's being held together with expensive last-minute actions. Yes, the lights have stayed on, but conditions have been really benign. I'm not sure we can be confident of the same outcome when demand is higher later in winter Adding insult to injury we hear that NESO has spent £££ on PR to gaslight us into thinking the grid was operated securely over the summer despite several margin warnings and lots of trading breaches. This week it has again tried to make us believe EMNs and EAs are just ordinary everyday tools and not exceptional actions. The cost and frequency data tell a different story And at a time when consumers are really struggling with high energy bills, NESO should be doing everything it can to avoid spending so much on balancing and interconnector trading - expenditure which gets added to bills via network costs @Miatsf @mgshanks @AndrewBowie_MP @ClaireCoutinho @HarrietCross_MP @drlukeevans @Ashley7Fox @ColinMoynihanUK @TiceRichard @DavidGHFrost @mattwridley @cmackinlay @Iromg @AllisonPearson @MerrynSW @EdConwaySky @afneil @mattotele @Jonathan__Leake @CitySamuel @neso_energy @neso_energy @ofgem