On 9th September national grid paid in excess of £80 per MWh just to balance the grid, pissing £40m away in just one day, at least tenfold what a normal day costs and the most expensive day on record.
Of the 10 most expensive days ever (beast from the east etc) 3 of them were In the first 10 days of September. (Edit: just checked the latest NG data and now 5 of the most expensive days in history are in the first 14 days of September)
We actually had to step in and bail out Ireland as they were about to have massive power cuts.
All these costs are an extra nail in the coffin of struggling suppliers and highlight the problems of the UK grid and our reliance on renewables and gas.